Sylvia Zukowski. in fulfilment of the thesis requirement for the degree of. Doctor of Philosophy. Charles Sturt University. Faculty of Science

Transcription

1 Impacts of fishing regulations on the sustainability of Murray crayfish (Euastacus armatus), Australia: Social and biological perspectives. by Sylvia Zukowski A thesis presented to Charles Sturt University in fulfilment of the thesis requirement for the degree of Doctor of Philosophy Charles Sturt University Faculty of Science School of Environmental Sciences Albury, New South Wales, 2640 Australia (Sylvia Zukowski), 2012 i

2 Based on the decrease in Murray crayfish numbers over the last ten years, there won t be any left for our kids to see in the next ten years, except for in a museum. Anonymous fisher

3 Table of Contents Certificate of Authorship... i Acknowledgements... ii Ethics approval... v Abstract... vi List of Figures... x List of Tables... xiii Chapter 1 General Introduction Background Thesis objectives How chapters are linked... 3 Chapter 2 Literature Review... 6 Fisheries Regulations Managing people, not fish!... 6 A review of inland recreational fisheries management and the Murray crayfish (Euastacus armatus) (Von Martens, 1866) Introduction Fishery Management Ecosystem-based fishery management (EBFM) Co-management of fisheries Values Conflicting values in fishery management Values of fishers Institutional levels Indigenous Australians Ecological effects of fishing Fisher knowledge Inland recreational fisheries management in Australia History... 26

4 2.4.2 Inland recreational fishing today Ecological Sustainable Development (ESD) & the Precautionary Principle State management Legislation Freshwater recreational fishing regulations in Australia History Basis for regulations Fishery regulation tools Measuring fish resources through fisher surveys Compliance of fishing regulations Are the current regulations working? Decline of native species Are the current regulations working? The Murray crayfish Murray crayfish (Euastacus armatus) background Conservation status Knowledge Local knowledge Knowledge gaps Recreational fishing regulations for Murray crayfish History of fishing regulations Size limits Consistency between regulations across NSW and VIC Summary...82 Chapter Is the Murray crayfish (Euastacus armatus) fishery sustainable? Insights from recreational fishers...83 Abstract Introduction Methods Participant selection...89

5 3.2.2 Fisher interviews Data analysis Results Fisher values, attitudes and norms Fisher local ecological knowledge Sustainability Fishing regulations Compliance rates Future management Discussion Conclusion Chapter Using fisher local ecological knowledge to improve management: the Murray crayfish in Australia Abstract Introduction Methods Participant selection Fisher interviews Fisher catch cards Crayfish surveys Data analysis Results Fisher interviews Fisher catch cards Scientific field surveys Fisher catch cards vs. scientific surveys Fisher interviews vs. fisher catch cards and scientific surveys Discussion

6 4.5 Conclusion Chapter Linking biology to fishing regulations: Australia s Murray crayfish (Euastacus armatus) Abstract Introduction Methods Crayfish surveys Year round catch rates Egg and hatchling timing Size at onset of sexual maturity (SOM) Percentage of sexually mature females in berry Egg dislodgement rates Data analysis Results Year round catch rates Egg and hatchling timing Size at onset of sexual maturity (SOM) Percentage of sexually mature females in berry Egg dislodgement rates Discussion Minimum Legal Length (MLL) Restricted fishing season Protection of berried females Conclusion Chapter Recreational fishing effects on Murray crayfish (Euastacus armatus) population dynamics in Australian rivers Abstract...148

7 6.1 Introduction Methods Talbingo and Blowering reservoirs Crayfish surveys Data analysis Results CPUE Size frequencies and sex ratios SOM Discussion CPUE Size frequencies and sex ratios SOM Conclusion Chapter 7 Spatial and temporal sampling designs to analyse the population dynamics of a broadly distributed freshwater crayfish Abstract Introduction Methods Study location Sampling design Sampling protocol Determination of population dynamics Data analysis Results Summary of population dynamics from spatial dataset Summary of population dynamics from temporal dataset Comparison between the two datasets Discussion

8 7.4.1 Murray crayfish population dynamics Comparison of spatial and temporal monitoring strategies Transferring data from detailed studies across a broader geographical area Implications for monitoring of Murray crayfish Implications for management of Murray crayfish Implications for monitoring and management of other spatially independent species Conclusion Chapter 8 Discussion Key findings Reliability of fisher LEK Better knowledge of the biology of Murray crayfish Effects of fishing Methods for understanding fish population dynamics Chapter 9 Conclusion Summary of major findings Summary of contributions based on knowledge gaps Reflection on research methods Management and policy implications Further research Summary of key points Chapter 10 References...214

9 Certificate of Authorship I hereby declare that this submission is my own work and that, to the best of my knowledge and belief, it contains no material previously published or written by another person nor material which to a substantial extent has been accepted for the award of any other degree or diploma of a university or other institution of higher learning, except where due acknowledgement is made in the acknowledgements. Any contribution made to the research by colleagues with whom I have worked at Charles Sturt University or elsewhere during my candidature is fully acknowledged. I agree that the thesis be accessible for the purpose of study and research in accordance with the normal conditions established by the University Library for the care, loan and reproduction of the thesis (subject to confidentiality provisions as approved by the University). Signature Date i

10 Acknowledgements This PhD was funded by the Institute of Land Water and Society and the Murray-Darling Basin Association. I would like to thank my supervisory team, Robyn Watts (CSU) and Allan Curtis (CSU) for all their help, advice and ongoing support along the way, and constructive review of chapters. I thank Robyn who I could drop in on any time and always had lots of ideas, solutions and questions. She was a constant source of encouragement and stability. Her ability to get things happening and help with things such as grants and field gear also made things much easier. Allan, with his one day review turnover times of chapters and papers, his amazing ability to make me feel that I was always succeeding and his vast knowledge and experience in the social dynamics that he was more than happy to share with me were all assets that I greatly thank him for and which made producing the thesis possible. I am grateful to all the fishers who by willingly sharing their knowledge, views and catch data, made writing this thesis possible. The attitude and kindness of the fishers also made interviews fun and sharing a beer with them while they told their stories made the field days much more interesting. My trusty four legged field partner Calum, who came out in the field with me even when no-one else was available and the weather was 40 o C or freezing and raining. Nick and Charlie Whiterod for slugging it out on the month long River survey and the annual Dam surveys. Also thanks to Nick for technical input, ongoing support, sense of humour and all the other bits and pieces that made home, work and PhD life bearable. Rhonda Sinclair and Stacey Kopf for field assistance and above all for all the champagnes, wines, lunches and nights out we had during my time in Albury. I will treasure these times and miss these two gorgeous girls dearly. Thanks to Simon McDonald (Charles Sturt University Spatial Data Analysis Network) who was extremely helpful in his technical assistance and Paul Humphries who always had an ii

11 open door policy and was happy to chat about ideas and problems and who also provided input on the methodology of my last research chapter. Thanks to Beck, Dave, Dot and Colin Whiterod and Iain Ellis, Tommy, Will and Finn Nixon for help in the field. A big hand to Dr Bern McCarthy for suggestions and helpful advice along the way and for comments on draft chapters and manuscripts of my papers. Thanks also to Cameron Westaway, Michelle Kavanagh and anonymous reviewers for comments on draft manuscripts of my papers. I wish to thank my family and friends, who continued to support me throughout my PhD and more importantly provided ongoing sources of fun and distraction that included trips to India (thanks Shaun and Clare), Vietnam and various spots in NSW and VIC and my initiation into the 100 club (thanks Iain and Kirst), the roasting of a 4-year old Jesus sheep for my 30 th birthday, yearly pilgrimages back to Adelaide where mum and Wally and dad and Stacia would always greet us at the door with vodka, wine, sausage and enough food to feed all of Poland and my Jess who would be there with a wine in waiting and an evening of fantastic catch ups. The staff at the MDFRC provided continuing friendship, great times and lots of ideas. And last but definitely not least, thanks to my gorgeous son Charlie Bear who was born in the third year of my thesis and whilst it made finishing it much harder, the amazement, laughter and new perspectives on life that he has bought to me has made the PhD journey an even more rewarding experience. iii

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13 Ethics approval This thesis was conducted under the conditions and requirements of relevant human and animal research permits. Murray crayfish surveys were conducted under a Charles Sturt University Wildlife Research Ethics Permit 07/142 and NSW Fisheries permit P08/0017 and OUT10/6463. The Charles Sturt University Ethics in Human Research Committee in accordance with the National Statement on the Ethical Conduct in Human Research approved the fisher interviews, catch cards and surveys. Ethics number: 2007/322. v

14 Abstract The decline in abundance and distribution of many native freshwater species throughout the Murray-Darling Basin has occurred in parallel with degradation of riverine habitats as a result of river regulation, land clearing for agriculture, cattle grazing, and the introduction of exotic freshwater species. Over-fishing has also contributed to the decline of native freshwater species. Murray crayfish (Euastacus armatus), an iconic native species once found throughout the Murray-Darling Basin has been affected by these threats to the extent there has been a reduction in both the abundance and distribution of this species. Recreational fishing regulations are in place to conserve Murray crayfish; however anecdotal reports by fishers suggest that the sustainability of this species remains threatened and that current regulations may be inadequate. Furthermore, there are large gaps in knowledge of the distribution, ecology, biology and habitat requirements of this species as well as the effects of fishing pressure and current fishing regulations on biological dynamics (distribution, abundance, genetic diversity, size-frequency ratios and sex ratios). There is also a lack of documentation of fisher local ecological knowledge (LEK) of Murray crayfish. These knowledge gaps attribute to uncertainty about the accuracy of current fishing regulations and management protocols for this species. In this research, I explored the impact of fishing regulations on the sustainability of Murray crayfish from both a biological and LEK perspective. To achieve this, three broad questions were examined: 1. What do stakeholders think about the sustainability of the Murray crayfish fishery? 2. What is the impact of recreational fishing on the sustainability of Murray crayfish? 3. What are the best research methods for collection of data to inform management decisions for Murray crayfish? To address the first question, I conducted semi-structured face-to-face interviews with 30 recreational fishers along a 230 km reach of the River Murray, from Hume Weir to Yarrawaonga Weir, NSW to explore their knowledge, values and experiences related to fishing for Murray crayfish. In addition, thirty separate recreational fishers independently completed single-trip fishing catch cards in the same river reach that enabled me to gather information about the date, time and duration of fishing, and the number, size and sex of Murray crayfish vi

15 that were caught. The majority of interviewees thought that Murray crayfish populations were not sustainable, as catch rates were likely exceeding sustainable levels, and believed that non compliance with fishing regulations was common. In line with these views, recreational fishers suggested changes were required to current fishing regulations, enforcement and community education approaches. They also stated that a total closure of the Murray crayfish fishery for two to five years was necessary to achieve long-term species sustainability. The comparison of data obtained through fisher interviews, fishing catch cards and Murray crayfish field surveys showed high similarities between the three methodologies. This finding suggested that fisher LEK can be a reliable source of information for managers wanting to improve fishery sustainability. The impacts of recreational fishing on Murray crayfish populations were investigated through the monitoring of Murray crayfish population dynamics between a recreationally fished (Blowering Reservoir) and non-fished reservoir (Talbingo Reservoir), and at recreationally fished reaches of the River Murray, NSW. Comparisons between fished and non-fished reservoirs revealed that in the fished reservoir Murray crayfish had a low abundance (0.02 individuals per net per hour), poorly represented size frequency distribution and uneven sex ratios with skews towards females most evident in size classes above the minimum legal length (MLL) (90 mm occipital carapace length (OCL)). In the non-fished reservoir Murray crayfish had a comparably higher abundance (0.22 individuals per net per hour), well represented size frequency distribution, approximately even sex ratios and a size at onset of sexual maturity (SOM) of mm OCL. In a recreationally fished 1,250 km reach of the River Murray (30 sites sampled once) and in a 230 km reach that was nestled within the 1,250 km reach (3 sites sampled monthly over 12 months), Murray crayfish exhibited abundances of 0.29 and 0.33 individuals per net per hour, respectively, SOMs of and mm OC, respectively, and significantly skewed sex ratios (toward females, particularly above 90 mm OCL). In addition, females were found to first come into berry 16 days after the commencement of the open fishing season and an experiment to assess the effects of handling of berried females on egg loss showed that an average of 1.3 eggs dropped off when the tail was left closed and 3.9 when the tail was opened. vii

16 The research findings raise concerns about the sustainability of Murray crayfish and recreational fishing impacts on this species. Biological information presented here depicts Murray crayfish populations with patchy distributions and significantly skewed sex ratios (toward females) in fished areas. These results and the significant differences in population dynamics between fished and non-fished areas suggest that recreational fishing may indeed be having a large impact on populations and that fishing regulations may need to be re-evaluated to ensure sustainable future populations of Murray crayfish. In particular, fishing regulations relating to the MLL and timing of the open fishing season may need to be re-evaluated. Further, the low and patchy distributions in the fished datasets are of concern and highlight the vulnerability of spatially independent sub-populations. Thus, as suggested by recreational fishers, a total closure of the Murray crayfish fishery may be advisable until populations to recover. Murray crayfish data from the spatial (1,250 km river reach) and temporal (230 km river reach) focused sampling designs were compared to determine the best research method for collection of data to inform management decisions for Murray crayfish. High similarities in the biological dynamics between the two sampling designs suggest that the choice of sampling method does not affect outcomes for characterising spatially-independent species. However, high variability within sampling designs demonstrates the need to (a) sample at a time of year which maximises CPUE and (b) maximise the number of sites to represent a larger proportion of the population. Further, where resources are scarce, sampling at a smaller geographical scale would produce beneficial information, as I found that the data from a small part of the species range was transferable to the whole population across a broader geographical area. Monitoring of Murray crayfish populations and the review of the appropriateness of fishing regulations should be an ongoing task. The aim of this research was to contribute new knowledge to assist a shift towards a more sustainable fishery. This research illustrates the wealth of knowledge that fishers have about their local resource and the management needs associated with it and that fisher LEK can indeed be a reliable source of information for use in fisheries management. It also highlights the effects of fishing and the associated fishing regulations on crayfish populations including changes in abundance, size frequencies and sex viii

17 ratios and effects of handling pressure on the eggs of berried females. This information is important not just for this species but for all fish and especially crayfish species which are fished and managed. The research also provides important information on the best monitoring strategies to effectively sample spatially independent species. From the information presented in the thesis, important changes to management strategies have been suggested such as the need for increased compliance rates and increased consultation and communication with the community and a total closure of the Murray crayfish fishery for two to five years. The main suggested changes to fishing regulations include decreasing the minimum size limit, the number of nets per campsite and changing the timing of the open season so that females have a chance to come into berry before the season commences. The LEK, biological contributions, monitoring proposals and suggested changes to management strategies and fishing regulations presented here should be considered to improve the sustainability of native species.. ix

18 List of Figures Figure 1. Co-management of fisheries Figure 2. Fish total length is measured from the tip of the snout on the upper jaw with the mouth closed to the tip of the tail Figure 3. Murray crayfish are measured from the rear of the eye socket to the centre rear of the carapace Figure 4. Influences leading to declined native fish species in Australia Figure 5. Illustration of a hoop net used to catch Murray crayfish Figure 6. Waterways closed to recreational fishing for Murray crayfish Figure 7. Murray crayfish eggs...78 Figure 8. Location of gonopores in male (a) and female (b) Murray crayfish Figure 9. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray between Hume Weir and Yarrawonga Weir in which fisher interviews were undertaken in Figure 10. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray between Hume Weir and Yarrawonga Weir in which fisher interviews, catch cards and scientific surveys were undertaken in Figure 11. OCL frequencies for male (grey bar) and female (black bar) Murray crayfish sampled by recreational fishers in 2009 in the River Murray, NSW (n = 198) Figure 12. OCL size frequencies of male (grey bar) and female (black bar) Murray crayfish, from scientific field surveys in 2009 in the River Murray, NSW (n = 421) Figure 13. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray, NSW, in which crayfish surveys were undertaken Figure 14. Total median Murray crayfish CPUE (Individuals per net per hour) (grey bars) from three sites in the River Murray, NSW (+/- Interquartile ranges) in 2009, plotted against water temperature ( o C) (black line) and daily discharge (ML day -1 ) (grey line) and timing of berries first present (black circle), larvae first present (grey triangle) and independent larvae (black triangle) (n = 421, net hrs = 1280) x

19 Figure 15. Median CPUE of Murray crayfish 90 mm OCL (Individuals per net per hour) (grey bars) from three sites in the River Murray, NSW (+/- Interquartile ranges) in 2009 (n = 60, net hrs = 1280) Figure 16. OCL frequencies (grey bars), SOM (size at onset of sexual maturity) per size class data (dots), fitted line (black line) and associated LC50 values (dashed line) for female Murray crayfish in the River Murray, NSW in 2009 (n = 248) Figure 17. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the location of the three River Murray sites and Blowering and Talbingo reservoirs in which crayfish surveys were undertaken Figure 18. Talbingo and Blowering reservoirs Figure 19. Female, male and total median Murray crayfish CPUE (Individuals per net per hour) (grey bars) from Talbingo (black bar) and Blowering (grey bar) reservoirs (+/- Interquartile ranges) in combined years (2008, 2009 and 2010) (n = 207, net hrs = 1787) Figure 20. OCL size frequencies of male (grey bar) (n = 93) and female (black bar) (n = 95) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Talbingo Reservoir (n = 188) Figure 21. OCL size frequencies of total female (black bar) (n = 95) and sexually mature females (grey bar) (n = 28) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Talbingo Reservoir (n = 95) Figure 22. OCL size frequencies of male (grey bar) (n = 8) and female (black bar) (n = 11) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Blowering Reservoir (n = 19) Figure 23. OCL size frequencies (grey bars), SOM data (dots), fitted line (black line) and associated LC 50 values (dashed line) for female Murray crayfish in Talbingo Reservoir (n = 95) Figure 24. Location of the sites used in the spatial (1-26) and temporal (3, 4 and 5) datasets to describe Murray crayfish in the River Murray, NSW. Note: site 1 is 2344 ATMD km and a there is 50 km interval between sites (site 26 is 1094 AMTD km) Figure 25. Murray crayfish abundance (CPUE) (Individuals per net per hour) along the 1,250 km sampled River Murray stretch in the spatial sampling dataset, 2009 (n = 383). 179 xi

20 Figure 26. OCL size frequency distribution for Murray crayfish populations taken from (a) spatial (females n = 232, male n = 151) and (b) temporal (females n = 248, male n = 173) datasets from the River Murray, Australia Figure 27. Sexually mature female Murray crayfish SOM spatial (grey bars and circles) (n = 54) and temporal (black bars and circles) (n = 50) datasets from the River Murray, Australia Figure 28. Summary of fisher LEK and biological data and its application to increase the sustainability of the Murray crayfish recreational fishery xii

21 List of Tables Table 1. Contrasts between conventional and ecosystem-based management Table 2. Summary of objectives of fisheries Acts in Australian jurisdictions Table 3. Acts (non fishery) included in Australian inland recreational fishery management Table Fishing regulations for native freshwater fish in NSW and VIC Table 5. Summary of purposes for the selection of minimum legal sizes in Table 6. Minimum legal size fishing regulations for freshwater fish species prior to Table 7. Minimum legal size recreational fishing regulations for freshwater fish in Table Fishing regulations for native freshwater fish in NSW and VIC Table 9. Input, output and access tools that can be used to manage a fishery Table 10. Changes to NSW freshwater fishing regulations, September Table 11. Conservation status of the Murray crayfish Table 12. Key Murray crayfish fishing regulations (1989 to 2008)* Table 13. Closed areas to Murray crayfish fishing in NSW and VIC Table Murray crayfishing regulations that are consistent across NSW (Tilbrook 2006) and VIC Table Murray crayfishing regulations that are inconsistent across NSW (Tilbrook 2006) and VIC Table 16. Key points for fisher interview schedule and associated probes Table 17. Recreational fisher LEK of Murray crayfish in NSW (fisher n = 30) Table 18. Summary of suggested changes to current fishing regulations for Murray crayfish in NSW as stated by the interview participants and the percentage of interviewers who suggested the change (fisher n = 30) Table 19. Summary of fishing regulations not complied with as listed by recreational fishers in NSW (fisher n = 30) Table 20. Summary of the fisher interview schedule xiii

22 Table 21. Fishers statements and associated hypotheses tested on Murray crayfish size and sex ratios in the River Murray in Table 22. Sex ratios of Murray crayfish obtained from fisher catch card results and scientific survey undertaken in 2009 the River Murray, NSW Table 23. Hypotheses tested through scientific and fisher catch card data on Murray crayfish size and sex ratios in the River Murray in Table 24. Number of Murray crayfish eggs dislodged under two treatments and under repeat captures (n = 71) Table 25. Sex ratios of Murray crayfish in the River Murray, NSW in 2009, and in Blowering and Talbingo reservoirs from 2008 to Table 26. Differences between the sex ratios of Murray crayfish in the River Murray, NSW in 2009, and in Blowering and Talbingo reservoirs from 2008 to Table 27. Summary and statistical comparison between spatial and temporal datasets describing sex ratio of Murray crayfish populations in the River Murray, NSW Table 28. Summary and statistical comparison between spatial and temporal datasets describing demographics of Murray crayfish populations in the River Murray, NSW xiv

23 Chapter 1 General Introduction 1.1 Background There are many definitions of sustainability; however the basic principle behind it is that all our needs rely either directly or indirectly on our natural environment and sustainability provides the conditions under which humans and nature can co-exist in harmony and fulfil the biological, economic and social criteria for present and future generations (EPA 2012). The aim of achieving sustainable fisheries has changed over time. Management goals originally focused on simply providing enough food to eat locally, then to providing enough food to supply national and international markets (Huxley 1883). Today, the management of sustainable fisheries has become more complex and aims have evolved to ensure an ecological, environmental and human balance so that ecological processes are maintained and the total quality of life, now and in the future, can be increased (National Strategy for Ecologically Sustainable Development, Council of Australia Governments, 1992). This is however a complicated task and as Glaser and Diele (2004) report in the mangrove crab fishery in North Brazil, the act of achieving harmony between biological, economic and social requirements are difficult to maintain. With marine and freshwater fish populations declining at an unprecedented rate (Sims and Southward 2006), the sustainability of fisheries world-wide has become a major concern over the past century. Indeed, the Food and Agriculture Organisation (FAO 1999) stated that most rivers, reservoirs and lakes have been fished to levels beyond their optimum. To help protect these valued resources, fisheries managers have had to expand and improve their management techniques and tools. Fishing regulations are now widely applied with the aim of ensuring healthy and sustainable fisheries for future generations (NSW DPI 2007; VIC DPI 2007). Regulations generally control inputs such as the number of boats, fishing gear and fishing times, and outputs such as size and quantity of catch (Hatcher et al. 2000). For regulations to be effective, they need to be based on sound information, include 1

24 values and information from stakeholders, be understood and supported by fishers and backed up by a significant level of enforcement effort (Nicol et al. 2005; Winstanley 1992). But there are many gaps in available information, both scientific and local. Murray crayfish (Euastacus armatus) (von Martens 1866), an iconic native and highly valued recreational fishing species in the Murray-Darling Basin, Australia, have been declining in abundance and distribution for the past 100 years. There is uncertainty about the exact causes, but declines have been related to degradation and regulation of rivers and over-fishing (Geddes et al. 1993). Murray crayfish can still be legally fished in New South Wales (NSW) and Victoria (VIC). Fishing regulations exist in both states for the management of this species; however; the sustainability of Murray crayfish remains questionable. Currently there are large gaps in the available information for Murray crayfish and published literature for this species is almost nonexistent. A scoping study was produced in 2007 that identified the knowledge requirements for Murray crayfish (Gilligan et al. 2007). That study and a review of past literature demonstrate that there are knowledge gaps in the distribution, ecology, biology and habitat requirements of this species. Furthermore, information on the effects of fishing pressure and the current regulations on the distribution, abundance, genetic diversity, length frequency ratios and sex ratios is very scarce, but is essential for future management of this species. A large knowledge gap also exists in the collation and documentation of local ecological knowledge (LEK) on Murray crayfish. However the use of LEK in fisheries management is limited by concerns about the reliability of that knowledge. There is also a need to decipher fishers values, attitudes, support and compliance in relation to current fishing regulations. Detailed information on available knowledge and knowledge gaps is presented in the literature review (Chapter 2, Section 2.8.4). 2

25 1.2 Thesis objectives The objective of the thesis is to explore the impact of fishing regulations on the sustainability of Murray crayfish in NSW from both an ecological and social perspective. Specifically, three broad questions are asked, with sub-questions under each of them. These are: 1. What do stakeholders think about the sustainability of the Murray crayfish fishery? (Chapters 3 and 4) 1.1. Is the Murray crayfish fishery sustainable from recreational fishers perspectives? 1.2. Can recreational fisher LEK be a reliable source of information for fisheries management? 2. What is the impact of recreational fishing on the sustainability of Murray crayfish? (Chapters 5 and 6) 2.1. Are current fishing regulations for Murray crayfish linked to the biology of this species? 2.2. Are there differences between Murray crayfish populations in recreationally fished and non-fished areas? 3. What are the best research methods for collection of data to inform management decisions for Murray crayfish? (Chapter 7) 3.1. Do spatial and temporal sampling designs produce the same results? 3.2. Are data from detailed studies in a small part of the species range transferable to the whole population across a broader geographical area? 1.3 How chapters are linked This thesis incorporates this general introduction (Chapter 1), a literature review on fisheries management, fishing regulations and Murray crayfish (Chapter 2), five research chapters (Chapters 3-7) and a general discussion (Chapter 8). The five research chapters focus on the fishing regulations for Murray crayfish and the associated sustainability of this species from a biological and social perspective. 3

26 Fisher LEK can provide detailed but often underutilised information about fishing resources and can guide the path for further questions. Thus, in the first research chapter (Chapter 3), I explore recreational fishers knowledge, values and experiences related to fishing for Murray crayfish (Euastacus armatus) and examine whether the Murray crayfish fishery is sustainable from the perceptions of recreational fishers in NSW (Q1.1). From the interview data presented in Chapter 3 and the literature review it was evident that one of the main reasons fisher LEK is generally underutilised in fisheries management is that the reliability of fisher LEK is often questioned. Thus, I next compare fisher LEK, fisher catch data and scientific data for Murray crayfish size and sex ratios in the River Murray to determine if these data are consistent and if fisher knowledge can be a reliable source of information for use in fisheries management (Chapter 4, Q1.2). Chapter 4 has been published in the journal Fisheries Research (Zukowski et al. 2011a). Fishers interviewed said they were noticing changes in the population structure and declines in numbers of Murray crayfish populations (Chapters 3 and 4). One of the reasons suggested by the fishers for these changes was inappropriate fishing regulations. There is also limited published biological information on which recreational fishing regulations can be based. There was therefore for a strong justification for investigating the biology of Murray crayfish and their link to fishing regulations. Thus, in the next chapter (Chapter 5), I investigate whether current fishing regulations for Murray crayfish are linked to their biology in a fished section of the River Murray, NSW (Q2.1). Specifically in this chapter, relevant elements of the biology of Murray crayfish including size and sex ratios, size at sexual maturity (SOM), catch per unit effort (CPUE) and effects of handling on berried females are explored in relation to fishing regulations and fishing for this species. Chapter 5 has been published in the journal Ecological Management and Restoration (Zukowski et al. 2011b). The data that are presented in chapters 3 to 5 were gathered in areas where recreational fishing for Murray crayfish occurs. As there is currently no information on the biological traits of Murray crayfish in virgin non-fished waters, nor are there many areas that have not 4

27 been or are not being fished either legally or illegally, baseline biological data for Murray crayfish is nonexistent. However, in order to understand the effects of fishing and fishing regulations on Murray crayfish populations, it is important to know what the benchmark is in natural or non-fished populations. As explained in chapters 1 and 2, fishers suggest that twenty years ago, prior to fishing regulations, Murray crayfish populations had equally distributed sex ratios, wide size frequency distributions and a higher distribution range and abundance than is currently found. Thus, in Chapter 6, the Murray crayfish biology traits that were reported in chapters 4 and 5 (size and sex ratios, SOM and CPUE), are used to compare crayfish in a fished (Blowering Reservoir) and non-fished (Talbingo Reservoir) reservoir in the Murrumbidgee catchment to determine the effect of fishing regulations on the sustainability of Murray crayfish populations (Q2.2). The data for the River Murray crayfish surveys in chapters 4 and 5 of this thesis were collected in a 230 km reach of the River Murray over a one-year period. Thus, in the last research chapter (Chapter 7), I discuss the biological traits (size and sex ratios, SOM and CPUE) of Murray crayfish obtained through sampling in a 1,250 km section of the River Murray over a shorter temporal period (one month) and compare these data with the biological data presented in chapters 4 and 5. In this chapter I aim to assess whether spatial and temporal sampling designs produce the same results and, if not, which one is most appropriate for the development of best management fishing guidelines (Q3.1) and whether data from detailed studies is transferable across a broader area (Q3.2). In the general discussion (Chapter 8), I summarise the findings of the five research chapters and discuss the contribution of my findings to the broader literature. In the conclusion (Chapter 9), I provide a summary of my main questions and findings and my major contributions to the broader literature. I then provide a reflection of the methodology used. Further, I evaluate the use of current fishing regulations and assess the impact of fishing regulations on the sustainability of Murray crayfish. I then discuss the implications of my research for management for Murray crayfish. I conclude the thesis by considering future research opportunities and management directions. 5

28 Chapter 2 Literature Review Fisheries Regulations Managing people, not fish! A review of inland recreational fisheries management and the Murray crayfish (Euastacus armatus) (Von Martens, 1866) 2.1 Introduction Murray crayfish (Euastacus armatus) (von Martens 1866), an iconic species in Australian river systems, was once widespread and abundant. Over the past century, this species has declined in abundance and distribution across the Murray-Darling Basin. Murray crayfish are now listed as threatened in South Australia (SA), the Australian Capital Territory (ACT) and VIC and are a part of the Lower Murray endangered ecological community in NSW (Gilligan et al. 2007). One of the main threats to Murray crayfish is over-fishing by recreational fishers (Geddes et al. 1993). The species is now protected in SA, where it is considered very rare or locally extinct, and in the ACT, but continues to be a popularly targeted species by recreational fishers in NSW and VIC. Fishing regulations which govern the time of year, number, sex and size of individuals that can be removed have been in place in NSW and VIC since However, the effect of these on improving Murray crayfish numbers is uncertain. It seems that fishing regulations are currently not doing enough to prevent the decline of native species such Murray crayfish. This view is supported by some local fishers who would like to see increased protection for the dwindling species and are frustrated by the lack of action by government authorities. Perhaps an integrated holistic approach, which includes biological, ecological and environmental information and stakeholder values, is required in order to sustain Murray crayfish in Australian river systems and provide a more successful approach to fisheries management. In this review I outline the history of fishing management. I then investigate the importance of values in fishery management, examine the role of fishery management and fishing regulations for freshwater recreational fisheries in Australia and look at the compliance of 6

29 fishing regulations by fishers. I also look into whether the current fishing regulations are working, using Murray crayfish as a case study. The conservation strategies, available information and knowledge gaps are also detailed for Murray crayfish, as are the fishing regulations. 2.2 Fishery Management In the late 1970s fishery management was generally defined as the practice of analysing, making and implementing decisions to maintain or alter the structure, dynamics, and interaction of habitat, aquatic biota and man, to achieve human goals and objectives through the aquatic resources (Lackey 1979). Fishery management in the mid 1990s was defined as the manipulation of aquatic organisms, aquatic environments and their human users to produce sustained and ever increasing benefits for people (Nielsen and Tomas 1999). The control of fisheries and fish production has been exercised in many places around the world for hundreds of years. The aims of fishery management have changed over the decades from simply providing enough food to eat locally, to providing enough food on a larger scale for trading benefits i.e. The supply of food is, in the long run, the chief of these [fishery management] interests (Huxley 1883), to where we are now aiming to ensure an ecological, environmental and human balance and the long-term sustainability of fish populations and biodiversity. Over the past century, most of the world's fisheries have been exploited, some to the point of severe degradation in response to the changing economic and regulatory environment (APFIC 2006). In 2008, worldwide marine and freshwater fish populations are still declining at an unprecedented rate, requiring greater international cooperation, research capacity and timely action (Sims and Southward 2006). Today, more than 52% of the world s marine fish stocks are fully exploited, meaning that they are being fished at their maximum biological capacity (AFMA 2008). Twenty four percent are over exploited, depleted or recovering from depletion. Twenty one percent are moderately exploited. Only 3% of the world's fish stocks are underexploited (AFMA 2008a). There is no comparable data for inland waters, but the FAO (FAO 1999) made the observation that most rivers, reservoirs and lakes have been fished to levels beyond their optimum. 7

30 It is thus now critical that fisheries be managed correctly, protecting the fish and the habitat in which they live, ensuring sustainability of healthy levels of fish populations and allowing responsible fishing (DPI NSW 2007a; DPI Victoria 2007b; MSC 2005). However, today there is still some disagreement among managers, fisheries, ecologists, conservation biologists, fishers and the general public as to the way forward with fisheries management. On a global level, there are now some basic assumptions that drive the way forward to long-term sustainable fishery resources (AFMA 2008a). These include the following: Sustainability of ecosystems is fundamental to achieving narrower management objectives. Humans are a part of the ecosystem. Human welfare depends on the sustainability of ecosystems. Effective management requires the incorporation of ecological, social, and economic considerations into management goals. Effective management requires individuals, groups, and agencies to be bought together to seek common goals. A change of attitude in fishery management has occurred over the past half a century in parallel with an increased realisation of the effects of fishing on dwindling fish numbers and a loss of biodiversity (Walters and Kitchell 2001). Fishery management authorities around the world have embraced the theory of ecosystem-based fishery management (EBFM) and co-management, and are stating that they are now more than ever focusing on the conservation of fishery stocks, ecosystems and the environment (i.e. EBFM), and are involving fishers, stakeholders and the broader community in the implementation of new management regulations (co-management) (AFMA 2008a). One example of this is the Australian Fisheries Management Authority (AFMA). This was established in 1992 with an aim to ensure healthy fish stocks as well as managing fishing in a way that takes into account its effect on the broader environment and minimizing detrimental environmental impacts (AFMA 2008a). The AFMA is the Australian statutory authority responsible for the efficient management and sustainable use of Commonwealth fish resources on behalf of the Australian community (AFMA 2008a). The operations of 8

31 AFMA are governed by the Fisheries Administration Act 1991 and the Fisheries Management Act These laws created a statutory authority model for fisheries management whereby everyday fishery management was vested in the AFMA, with the broader fisheries policy, international negotiations and strategic issues being administered by a smaller group within the Department of Agriculture, Fisheries and Forestry (AFMA 2008a). The management structure of the AFMA was implemented in order to overcome problems of excess capacity and over-fishing, and to allow fishers and other stakeholders direct involvement in fisheries management decisions (Gooday and Galeano 2003) Ecosystem-based fishery management (EBFM) Conventional fisheries management has focused on the management of single species (Hilborn 2004; Walters and Kitchell 2001). Management has been directed towards the abundance of individual stocks and the direct effects of exploitation on single species stock productivity (Walters and Kitchell 2001). This management style, combined with the impact of increased fishing pressure with increasing world populations and technology, which enables fishers to target fish more effectively, has led to the over-exploitation of fisheries around the world (Hilborn 2004; Stevens 2005). The ongoing significant depletions of fish stocks and their unexpected or unknown ecosystem consequences, has lead to the realisation that the majority of single species techniques are unsatisfactory when considered on their own (Bundy 2001; Jackson 2001; Longhurst 1998; Myers and Worm 2003; Myers and Worm 2005). During the previous two decades, the focus has shifted towards management of ecological interactions at more holistic levels. These issues now generally involve tradeoffs and interactions within and between nature and people (Field and Francis 2006). It was in the late 1980s that these realisations led to formalisation of ecosystem-based fishery management (EBFM) by the environmental historian Arthur McEvoy (1986). This was one of the first concepts that was used to work with communities and fishery management to achieve desired management outcomes (Adelman 2007). McEvoy (1986) based the context for the establishment of EBFM on the history of the California fisheries. Ten years later, he built on this experience and defined a sustainable fishery as follows: What a fishery is, descriptively, and what management ought to try to sustain, prescriptively, is an interaction between three 9

32 variables: an ecosystem, a group of people working (economy), and the system of social control within which the work takes place (management) (McEvoy 1996). Since its formation, there have been many definitions of EBFM. Grumbine (1994) has synthesised these definitions and produced one that encompasses them: Ecosystem management integrates scientific knowledge of ecological relationships within a complex socio-political and values of framework toward the general goal of protecting native ecosystem integrity over the long-term (Grumbine 1994). By using EBFM, fisheries managers aim to equally include the vast social and economic relationships within fisheries with the ecosystem processes and dynamics and incorporate how they are influenced by one another (McEvoy 1996). McEvoy (1996) stated that a fishery is a classic example of a social-ecological system which integrates humans and nature. The most important elements of EBFM are further defined as making sure that ecosystem-wide overfishing does not occur, by-catch is kept low and that habitats are protected during fishing activities (Hilborn 2011) and recent publications have demonstrated that effectiveness of current uses of EBFM (Castrejon and Charles 2011; Gascuel et al. 2011; Yeon et al. 2011). The increasing use of EBFM at a management level has necessitated the development of scientific tools and socioeconomic indicators to help guide the practical implantation of EBFM (Kim and Zhang 2011; Smith et al. 2007). Scientific tools include methods to evaluate broader EBFM strategies and the development of novel ideas to evaluate the ecological impacts of fishing (Smith et al. 2007). Socioeconomic indicators for EBFM were developed to be incorporated with ecological and biological indicators to enable the detection of changes in ecosystems and the application of a ecosystem-based fisheries assessment to guide management (Kim and Zhang 2011). There is a strong link between EBFM and ecologically sustainable development (ESD). EBFM has been defined as a subset of ESD that can act as an operational mechanism to aid the progress of ESD (Fletcher 2006). In Australia, EBFM is more evolutionary than revolutionary. The revolution is occurring with the mainstream incorporation of ESD into fisheries management (Al-Humaidhi et al. 2012; McPhee 2008; Vainikka and Hyvarinen 2012) (see Section 2.4.3). In 2000 a ESD framework was developed at a national scale in 10

33 Australia based on a number of case studies and stakeholder workshops (Fletcher et al. 2005). Based on this framework, an ESD report is completed for a fishery through the implementation of four key steps which include the identification and prioritisation of relevant issues and the completion and compilation of reports of each of the issues (Fletcher et al. 2005). Table 1 lists the differences between conventional management and the ecosystem management that is now being used in fishery and other natural resource management. Table 1. Contrasts between conventional and ecosystem-based management. Source: (Adelman 2007) Conventional management Emphasis on commodities and natural resource extraction Equilibrium perspective Reductionism; site specificity Predictability and control Solutions developed by resource agencies Confrontation, single-issue polarization; public as adversary Ecosystem management Emphasis on balance between commodities, amenities and ecological integrity Nonequilibrium perspective; dynamics and resilience; shifting mosaics Holism; contextual view Uncertainty and flexibility Solutions developed through discussions among all stakeholders Consensus building; multiple issues, partnerships Co-management of fisheries Fisheries management should be tailored at managing people, not fish. Fishery resources are the common-property of all of the community. In line with this perspective, over the last decade fishery resources have been increasingly co-managed through the interaction between government and fishery management organisations and in consultation with stakeholders such as fishers, conservation groups and local communities (Heyman and Granados-Dieseldorff 2012; Jentoft et al. 1998). Co-management can be defined as a partnership arrangement in which government agencies, the community of local resource users (fishers), non-government organisations, and other stakeholders (fish traders, boat 11

34 owners, business people, etc.) share the responsibility and authority for the management of a fishery (Fig. 1) (Pomeroy 1998). Co-management differs from community-based resource management (CBRM) as the government is also involved in the decision making process in co-management (Sen and Raakjaer-Nielsen 1996). CBRM has been defined as: A process by which the people themselves are given the opportunity and/or responsibility to manage their own resources, define their needs, goals and aspirations, and to make decisions affecting their wellbeing (Sajise 1995). Fisheries co-management has resulted in a shift of management from top-down to bottomup approaches that include the government sharing responsibility and decision making with fishery stakeholders (McCay and Jentoft 1996). Internationally, there have numerous examples of successful co-management investigations and reviews that have occurred in the last decade. These include, but are not limited to, Brazil (Da Silva 2004; Kalikoski and Satterfield 2004), Chile (Gelcich et al. 2004), Denmark (Nielsen and Vedsmand 1997), the Gulf of Honduras (GOH), shared by Belize, Guatemala, and Honduras (Heyman and Granados-Dieseldorff 2012), New Zealand (Yandle 2006), Norway (Soreng 2006), Spain (Suarez de Vivero et al. 1997), Sri Lanka (Nathaneael and Edirisinghe 2002) and the United States (Acheson and Taylor 2001; Carr and Heyman 2012). Many overseas examples include co-management changes made at an institutional level in an advisory capacity with committees being created to help increase fisher involvement in the resource (Fisheries Research and Development Corporation 2008). However some example where fishers have successfully taken the management responsibilities of comanagement into their hands include the management of quota arrangements in the New Zealand Rock Lobster fishery, management of fishing regulations and conflict resolution Maine Lobster fishery, management of fishing regulations and their enforcement in the Canadian Atlantic Sea Scallop Fishery and the management of quotas in the Dutch Biesheuvel fishery (Fisheries Research and Development Corporation 2008; McPhee 2008). Overseas cases have provided information about some of the challenges which can be faced during the co-management approach which also apply to Australian fisheries. These have 12

35 been summarised by the Fisheries Research and Development Corporation (2008) as follows: There is often little unity of purpose from fishers to take on additional tasks and responsibility. The voluntary nature of fishers organisations means it is impossible to impose common approaches on all fishers. Fisher organisations also find it difficult to resolve internal conflicts. There is often a lack of skills, resources and experience in fisher groups to take over many tasks. It is often difficult to clearly delineate individual fisheries from overlapping fisheries or overlapping regional boundaries. Fisheries with multi-user groups significantly complicate co-management negotiations. It can be difficult to gain consensus from a wider group of stakeholders that need to be involved in co-management than just the fishers themselves. Transaction costs may need to be significantly high before there is sufficient will for negotiations towards co-management to occur. In Australia, co-management was initially partially driven by the ESD Working Group report which was one of the first to call on public comment and input in relation to developing fishery management plans (McPhea 2008). It was also driven by the realisation that the inclusion of stakeholders in the decision making of fisheries management would lead to enhanced management and would have a greater chance of success (Johnson et al. 2003; Pretty and Smith 2004). Finally, with the present inclusion of fishing fees for commercial and recreational fishing that pay for a large amount of the management costs associated with fishing, the user pays, user says adage has relevance (McPhea 2008). Much attention has been directed at co-management as a tool for fisheries management in recent years. Although there are high hopes about what it may be able to accomplish, there are also significant and very real doubts, questions and criticisms regarding its general applicability (McPhea 2008). In Australia, there are ongoing investigations into the arrangements of co-management of fisheries (McPhea 2008). In 2006, a working group was formed by the Fisheries Research and Development Corporation to help guide comanagement of fisheries in Australia and assist in obtaining the best possible environmental, social and economic outcomes from fisheries (Fisheries Research and Development Corporation 2008). The group undertook the Fisheries co-management 13

36 initiative project in order to provide information for a broad audience and for individual comanagement projects (Fisheries Research and Development Corporation 2008). Some examples of successful co-management cases in Australia include the Spencer Gulf prawn fishery in South Australia and the New Zealand Southern Scallop Fishery in the Nelson Marlborough Sound area. In both of these cases the success has been largely attributed to use of a broader ecosystem approach to the management of fisheries instead of simply concentrating on one species (Fisheries Research and Development Corporation 2008). Although co-management has been used for the last decade, the outcomes of it have not yet been subjected to vigorous research. Co-management is not a solution to fishery problems but an adaptive tool that can help solve some of these problems and lead to better management outcomes (Carlsson and Berkes 2005). Anglers External Agent Non government organisation Academic Fishery Management Government National Regional State District River Stakeholders Tourism Industry Hotels Fisheries Stakeholders Boat owners Money lenders Recreational fishers Figure 1. Co-management of fisheries. Adapted and altered from (Pomeroy 1998) Values In managing environmental resources such as fisheries, it is vital to understand how all stakeholders value the resource (Lockwood 1999) and how people s values can best be 14

37 incorporated in the management of the resource. Stakeholders of a fishery can include fishers, community groups, landholders adjacent to river or wetland reaches, conservation groups, fishery management agencies and local and national governments. Between and within each of these groups, a wide range of similar and conflicting values are inevitable regarding the management of fisheries. Values are learned through experiences. Both long- and short-term experiences can affect evaluations and beliefs regarding both concrete objects and abstract ideas (Breer and Locke 1965). Values that may be involved in the decision making of natural resource issues such as fisheries are developed with the context of social norms, individual socioeconomic attributes, and understanding of the policy issues (Lockwood 1998). Fishery managers in Australia have recently begun to try to include the values of fishers into the development plans of some species (i.e. North East Fishery Management Plan) (DPI NSW 2006). However, the effects of including values in the management of Australian fishery management not yet been investigated. Indeed, even at a global level, there is only a limited understanding of people s values, the ways in which people express values, how values can be incorporated into management decisions and how values change (Lockwood 1999). There is a growing need for natural resource managers to incorporate values into management designs to help achieve sustainable outcomes (Burkett 2006). Although there is an increasing amount of literature on ecological and socio-economic values associated with the management of natural resources (de Groot et al. 2002) there are ongoing debates between the social balance of utilising resources and keeping a healthy co-evolution between the environment and people (Burkett 2006). Natural resource managers often utilise values associated with people s satisfaction of preference where individuals select or use those resources that will make their life most enhanced and able them to attain the resources they wish. The inclusion of such social-economic values based on individual s choices often underpin management guidelines as these values mainly incorporate economic considerations which are favoured by natural resource managers (Diener and Eunkook 1997). However, management decisions based on economic indicators are based on the assumption that resource users share a common view of the resource where the 15

38 extraction of the recourse and economic incentives are the main focus (McFarlane et al. 2011). Further the inclusion of economic values into policy does not prevent crime and illegal activities taking place (Diener and Eunkook 1997) (for further information on compliance behaviour please refer to section 2.6.2). Values have been defined by Rokeach (1979) as standards or criteria that guide action as well as other psychological phenomena such as attitudes, judgments and attributes. He goes on to add that values are considered deeper and generally more stable than attitudes and are classed as determinants of attitudes (Rokeach 1979). The difference between values and other factors such as behaviours and attitudes can be briefly summarized in that values are slow to change, few in quantity, central to beliefs, and transcend situations, whilst value orientations, attitudes and norms, behavioural intentions and behaviours change linearly in that order to become slow to change, numerous, peripheral and specific to situations (Fulton et al. 1996). The term values has been used widely to identify selective orientations such as but not limited to likes, preferences, interests, duties, moral obligations, wants, goals and needs (Williams 1979). Thus, it seems that values generally guide people s decisions and actions. Biocentric values are generally centred around living things (Halpenny and Caissie 2003) and are relevant where preservation of the environment or an environmental resource is underpinned by beliefs that people have obligations to the natural environment that stem from the intrinsic values in nature, over and above those of human survival, economic, recreational or aesthetic purposes (Halpenny and Caissie 2003; Pluhar 1983; Rolston 1981). Held values are ideas or principles that are important to individuals. They include notions of responsibility, liberty or justice, or beliefs about biocentric values (Brown 1984). They are generally categorised into instrumental or means values (i.e. generosity, courage, obedience, responsibility, fairness and frugality) and terminal or end values (i.e. happiness, freedom, equality, beauty, pleasure, friendship and wisdom) (Brown 1984). Held values can lead to assigned values. Assigned values are those that individuals attach to things, or express the importance or worth of, relative to other objects such as places, services, objects, or activities (Brown 1984). The difference between these two sets of values should 16

39 not be overlooked in the management of natural resources and both of these values should be included in management (Brown 1984). Intrinsic values indicate that the referent entity is an end to itself and as such the value is autonomous and independent of any other entity (Lockwood 1999). Intrinsic value beliefs are likely to influence the way in which a person makes a decision about environmental resources (Lockwood 1999). For example, although someone s support of nature does not necessarily have to imply that that person has a strong belief in the intrinsic value of nature, the two factors do generally have a high level of correlation between them (Lockwood 1999). Furthermore, it is logical that these values would have a strong effect on their beliefs, attitudes and so choice of decision. Managers and stakeholders alike generally have to decide on fishery management actions with a very limited knowledge backing or experience. In such cases, people s value orientations are likely to be especially strong in determining their choice of action (Stern and Dietz 1994). A value orientation as described by Axelrod (1994) is the position taken by a person where a particular set of related held values are more important to them compared to all others. The following three value orientations have been identified by Axelrod (1994): 1. Economic: Desire for material well-being. 2. Social: Need for belonging and acceptance. 3. Universal: Self respect from contributing to societal improvement regardless of personal and social costs. With the increasing pressure from the worldwide conflict of increasing resource use and environmental conservation, these three value orientations can be conflicting when people make decisions about environmental resources. This can especially be true where the increased rewards from one area can directly lead to detrimental actions in another area. For example, hypothetically speaking, fishers may act on economic value orientations, catching more fish and disregarding fishing regulations. This would in turn lead to diminishing fish supplies and a detrimental effect on the sustainable management of fishing resources. 17

40 Axelrod (1994) developed a number of hypotheses relating to the interactions between the listed value orientations and environmental behaviour as follows: 1. Economically oriented people would be more likely to engage in environmentally protective behaviour when it was linked with some economic benefit. When no such link is evident, economically oriented individuals would be guided by other behavioural cues and may or may not act in support of the environment. 2. Socially oriented individuals would be more likely to participate in environmental preservation, particularly when there is a social benefit associated with their decision. 3. Universally oriented individuals would be more likely to favour environmental protection. 4. Universally-oriented people would be more likely to pursue decisions that favour environmental protection over those who are more economically oriented. Axelrod (1994) found that people acting on universal value orientations were most likely to support environmentally protective actions (Axelrod 1994). However, this research was not tailored to fisheries resources. It would be interesting to determine the value orientation that fisheries stakeholders most likely act on when determining their choice of management decisions and when determining their support and in the case of fishers, their compliance with fishing regulations. For this to occur, stakeholder values would need to be expressed and captured in some way. This can be achieved through the use of surveys (Clement and Cheng 2011), interviews, citizens juries, planning cells, focus groups, or through behavioural methods such as whether fishers comply with fishing regulations or whether they pay their licence fee Conflicting values in fishery management Values in fisheries can be very different between and within different groups of people. For example, for fishing managers, values may focus on a well-managed resource free from disease, access for harvesting and farming fish, a sustainable harvest and for viable and competitive industries. For the general community, values might be focussed on the maintenance of healthy rivers and fish habitats that support a diverse range of species. 18

41 Values for recreational fishers might, among others, encompass the possibility of catching a large fish and the pleasure that comes from fishing. Values for Indigenous communities might be centred on maintaining and preserving local customary fishing practices (DPI NSW 1997). With such broad and differing values surrounding one resource, conflicts regarding the management of the resource can and usually do arise. Such conflicts can arise for a number of reasons that include the simultaneous value of a natural resource such as a fishery in a number of different ways (Trainor 2006; Vaske and Donnelly 1999), the implementation of management practices that affect the strong views that stakeholders hold about fishery resources (Davies 2001) and failure by fisheries managers to take stakeholder values into consideration during the management process (O Brien 2003). Trainor (2006) outlined some of the ways in which values can conflict in the management of an environmental resource. Economic values may clash with ecosystem, aesthetic or social values. For example, research was undertaken at a mangrove crab fishery in North Brazil where over half of coastal households rely on the fishery for part of their income (Glaser and Diele 2004). Researchers found that although the fishery was sustainable from a biological perspective, an economic threshold had been reached and increasing territorial disputes between fishers meant that the economic and social sustainability of the fishery was under threat (Glaser and Diele 2004). Values within the same stakeholder group or realm may vary leading to differences as to the best management decisions. There can be a conflict across different levels or loci of stakeholders such as managers, scientists and fishers. Finally, values can conflict within and between nested geographic areas such as local, regional, state, national and global domains (Trainor 2006). The fisheries section of the Department of Primary Industries (VIC) states that it is often difficult to reconcile the vast differences in the environmental, social and economic values of external stakeholders of fishery resources such as recreational users, fishers and the broader community (DPI Victoria 2006). However, for fishery management to be effective, it needs to be supported and adhered to by stakeholders and management needs to be perceived as being effective (Smith 2004). This can occur only if management decisions 19

42 include an appreciation of stakeholder values and are also based on the reality of meaningful input from stakeholders (Lockwood 1999; Smith 2004). Fishery management therefore requires the need for a deliberative process to take place in which all interested and affected stakeholders collectively come to a decision outcome that is mutually agreed upon (Trainor 2006). However, when managing a complex resource such as a fishery, this is not always possible, and this can be seen by the high degree of disregard that occurs for fishing regulations (West and Gordon 1994). For the deliberative process to be successful in ensuring all stakeholder views are accounted for and that the process is successful in managing the resource, a number of key steps must be taken. First, members for each and every representative party or stakeholder group must participate in the process to account for the full range of values and ensure that all stakeholders will stand by the final management outcome (Susskind et al. 1999). Second, the collaborative process requires a relative balance of power between stakeholders (Trainor 2006). Third, there must be mutual trust and respect between all parties (Trainor 2006). This process is not always utilised. For example, during a fishery stakeholder meeting in early 2000, where anglers were present, fisheries managers referred to anglers during the meeting as Joe Six-Pack Angler. Michael Lockwood, an angler in the U.S. who was present at the meeting, refers to the countless times that anglers felt they had not been levelled with by state fishery agencies and he stated that that fishery managers generally tried to use a blind them with our science approach when dealing with the public and the media (Smith 2004). These types of actions can be damaging to the public s trust in fishery management. The final key step in a success deliberative process is to ensure that enough time is assigned to this complex task (Trainor 2006). The values people and groups hold for fisheries resources are often complex and multiple, and conflicts arise when fisheries managers fail to take these into consideration or when these values clash. Perhaps more information about the depth and breadth of values for fisheries resources would provide important information to fishery decision makers about best management practices (O Brien 2003). 20

43 2.2.5 Values of fishers A typical recreational fisher does not really exist from a demographic perspective. Recreational fishers come from all walks of life and the crossing of social, cultural and economic boundaries contributes to the appeal of recreational fishing. Bankers, farmers, lawyers and pilots all have a common discussion ground if they are recreational fishers (McPhee 2008). The most commonly used paradigm for understanding the multidimensional aspects of fishers values, attitudes and behaviours is generally referred to as recreational specialisation (Bryan 1977; Ditton et al. 1992; Oh and Ditton 2006). The identification of various groups of recreational fishers can be achieved along this continuum of specialisation using factors such as the equipment fishers use, how often they fish, why they fish, when they fish, who they fish with, the importance of catching fish and their compliance with fishery regulations and management policies (Bryan 1977). Two extreme groups of recreational fishers along this continuum can be explored. First, there are the fishers who go fishing maybe once or twice a year as a leisure pursuit, perhaps while they are on a holiday. This type of fisher generally will not have a specific species in mind and will have minimal equipment. This fisher also frequently has limited interest or involvement in the management of the fishery resource. On the other extreme of the continuum, there are the avid recreational fishers who consider fishing a way of life, go fishing frequently and have invested in extensive fishing equipment. Fishers from this group are more likely to belong to an angling club and take part in fishing competitions (Hilborn 1985). They are also more likely to have a heavily invested interest in the management of fishery resources and the implementation of fishing regulations and are more likely to sit on management advisory groups (McPhee 2008). In respect to the two extreme groups described above, the majority of fishers are represented by the first group of fishers, the once a year fishers. Therefore, the majority of all fishers have a low catch rate of fish and the small number of highly skilled fishers catch the majority of fish. McPhee (2008) provides some figures relating to this by estimating that as a general rule, 10% of recreational fishers catch 90% of the recreationally caught fish. 21

44 The values that underpin the attitudes and behaviours of these two extreme groups and all the stakeholders who fall between these groups would almost certainly differ between and within groups and demographic locations. Therefore encompassing the values of all involved in fishery management decisions is a complex and difficult task. However, if fishery managers can ensure that all stakeholders and potential stakeholders values are reflected in the management of fisheries resources, policy and regulations will be more likely seen as fair by all stakeholders (O Brien 2003). Further, the input of stakeholder values into the decision making process can provide individuals with a sense of local identity and increased feelings of involvement, and can lead to a sense of ownership associated with local fishing resources (O Brien 2003). This is turn can lead to higher compliance levels with fishing regulations and thus a more sustainable fishery Institutional levels The values at institutional levels and their influence in the decision making also need to be examined. As well as understanding the values that fishers and community stakeholders have for fishery resources, it is important to investigate the values of managers and researchers and how their values affect their interactions with the public and their role in the management of a fishery (O Brien 2003). Dunn (2004) examined the ecological values that river managers place on the conservation of Australia s rivers. The research revealed that the values held by managers varied widely, but that the need for naturalness was the most cited value in relation to the conservation of Australia s rivers (Dunn 2004). Although this study did not specifically refer to fishery resources, it is the closest that any study has come to examining values of managers in environmental issues. It would be interesting to compare the values of managers, researchers and other stakeholders such as fishers in relation to fishery management Indigenous Australians In Australia, Indigenous people are still practising traditional fishing in some inland and coastal areas. Franklyn (2003) describes traditional fishing as being applied to people of an Aboriginal descent, who are fishing for the purpose of satisfying personal, domestic, ceremonial, educational or non-commercial communal needs and who are accepted by the Aboriginal community in the area being fished as having a right to fish in accordance with 22

45 Aboriginal tradition. The management of fishing by Indigenous people varies between Australian states and territories. For example, in the Northern Territory (NT), Western Australia (WA) and Queensland (QLD), Indigenous people are exempt from fishing regulations under certain conditions. In NSW, Indigenous people abide by the Indigenous fisheries strategy and implementation plan (DPI NSW 2002). The strategy aims to support the values and the greater involvement of Indigenous people in the management of the NSW fisheries resources, and encourages the involvement of Aboriginal communities in the emerging aquaculture industry (DPI NSW 2002). As key stakeholders in Australia s fisheries, the values of Aboriginal people need to be, and in the majority of cases are, reflected in fishery management decisions. At state levels in Australia, Aboriginal consultants now form part of the management committees for the implementation of the majority of the fishery management decisions (DPI NSW 2007a; DPI Victoria 2007b) Ecological effects of fishing The effects of fishing on ecological processes, habitat and on the productivity and diversity of benthic communities can be both direct and indirect (Jennings and Kaiser 1998). For example, in the North Sea fishing pressure not only removes 30 to 40% of fish biomass every year but is also responsible for the death of fish species caught as by-catch which is discarded during fishing activities and of non-target animals such as seabirds, marine mammals, other fish species and benthos (Gislason 1994). By-catch can also increase population numbers of scavenging species such as seabirds (Jennings and Kaiser 1998). The modification of habitat through fishing practises such as bottom trawling can result in interruptions to significant ecological processes, benthos being raked and the mortality of epibenthic animals and plants (Auster 1998). However, it is not only bottom trawling which can pose such significant effects. The effects of mid and surface long-line fishing have also been reported with significant declines in the abundances of leatherback turtles and high death rates of seabirds, respectively (NRC 1995). The severity and duration of fishing effects can be heightened in regions which are exposed to infrequent natural disturbance and in previously non-fished systems (Jennings and Kaiser 1998). The introduction of fishing to a non-fished area can dramatically change the community structure of not only the fish being targeted (for more information please see 23

46 Chapter 6) but also of many forage fishes leading to follow on effects on bird and marine mammal abundances (Jennings and Kaiser 1998). The introduction of fishing to coral reefs can have a dramatic direct role through the destruction or modification of habitat and also an indirect role where prey or predator species which begin to be fished fill an important role resulting in a shift in alternative stable states of ecosystems due to the disruption to the tight predator-prey coupling (Jennings and Kaiser 1998). Indeed, populations of top level predatory fish have been locally extinct or reduced in this manner. The removal of larger fish through fishing pressure can cause a change in the mean length or weight of a population (Shin et al. 2005). Further a reduction in the numbers of top predators, even at lower quantities or at a recreational fishing scale can lead to cascading top down effects which can decrease diversity or productivity of food webs and increase the survival rates and numbers of smaller fish as predation pressure on them is reduced (Agardy 2000). 2.3 Fisher knowledge Fishers often have a broad and detailed knowledge of fisheries stemming from ongoing and frequently extensive interactions with the environment (Johannes 1981; Ruddle 1994). They can provide species specific information about population dynamics and biological and ecological aspects including reproductive parameters such as migration patterns, seasons and places (Silvano et al. 2006), spawning grounds, juvenile habitat, migration patterns and habitat preferences (Ames 2004; Hall-Arber and Pederson 1999; Maurstad and Sundet 1998; Neis et al. 1999). Fishers can also provide information about changes in stock and fishing pressure in response to regulatory changes (Neis and Felt 2001) and can often be the first to detect an environmental problem or change, or suggest when regulations need to be introduced or changed (Alexander 2008). It is no surprise then that the literature suggests that fisher knowledge can complement scientific information (Johannes 1998; Johannes et al. 2000), improve decision making (Baticados 2004; Berkes and Folke 1998), and provide practical knowledge that can be used to improve fishery management (Bergmann et al. 2004; Silvano and Begossi 2005). 24

47 Recreational fishing surveys provide a range of data for fisheries managers and can be implemented through door-to-door, mail or telephone surveys, logbooks and diaries, and can occur at fishery access point, by aerial or roving surveys (Pollock et al. 1994). In Australia, recreational fishing surveys began in the 1970s and since then the majority of state fisheries conduct routine surveys (Henry and Lyle 2003). However, survey objectives, temporal and spatial scales and methodologies are generally inconsistent (Henry and Lyle 2003). Further, whilst they can provide ongoing data if they are well designed and resourced, they generally use one-off point data sources and do not provide ongoing data on a continuous basis. Although state and national recreational fishing surveys have been undertaken in Australia, the debate as to the best way to incorporate fisher data and knowledge into fisheries management remains ongoing. This is due to a number of reasons. Fishery managers must be able to ascertain the reliability of so called anecdotal evidence, and they need the information to be available to them in a form that is readily useable (Neis et al. 2007). However, the engagement of fishers in decision making processes is likely to enhance their acceptance of the legitimacy of management and increase commitment to conservation and management aims. This could lead to higher compliance rates and better management outcomes (Castello et al. 2009). A small number of papers have compared data collected by fishers with data collected by scientists (Baigòn et al. 2006; Bray and Schramm 2001; Ebbers 1987; Rochet et al. 2008; Silvano et al. 2006; Silvano and Valbo-Jørgensen 2008; SilvanoI and BegossiII 2012) or data volunteered by recreational fishers and data that commercial fishing operators are obliged to provide. Recreational fishers are seldom required to provide fishing trip reports or catch rates and generally do not have an opportunity to feed their knowledge and observations into the management of fisheries. Occasionally this occurs through voluntary surveys (Gerdeaux and Janjua 2009; Mann et al. 2002). A number of issues can arise from this. The knowledge generated by fishers can often be left underutilized, a lack of consensus on the status of fish stocks can occur, and compliance rates with fishing regulations can be affected. Fishers often feel that scientific investigations provide one off snap-shot assessments that are not accurate and often take 25

48 place once a problem has been evident for some time. When science is distrusted (Dobbs 2000) and fishers are not engaged in management processes, the perceived legitimacy of fishing authorities and fisheries regulations can be weakened, leading to lower compliance rates (Tyler 1990). 2.4 Inland recreational fisheries management in Australia History In Australia, fishing played a major role in the life of Aboriginal people prior to the colonisation of the continent by Europeans (Pownall 1979). In many Aboriginal tribes, fish were used as a staple diet and valuable trade source and were also of great cultural significance (Kearney and Kildea 2003; Pownall 1979). Their knowledge of fish movement allowed them to erect fixed and moveable barriers and traps in rivers and lakes and along the sea front to catch fish (Kailola et al. 1993; Pownall 1979). Pre-European fishing activity is well documented in Port Jackson (Attenbrow and Steele 1995) and in south-western Australia (Dortch 1997). Although fish made up a large component of the staple diet of Aboriginal communities, the fishing activities of Aboriginal people does not appear to have had a large impact on fish populations or distributions (DPI NSW 1997). Some of the earliest European descriptions of primitive fishing were described by British navigators, Dampier and James Cook in 1688 and 1770 respectively (Pownall 1979). At the time of Cook s travels, the idea that over-fishing could lead to the exploitation of fish resources was ludicrous. This view seems to have been maintained until a global alarm was raised with the remarkable failure of haddocks due to over-fishing in the north of England (Pownall 1979). The first fisheries observations from Australia were probably those of Joseph Banks on 23 April 1770 in NSW where he used a dipping net to sample and classify plankton, the megalope-larva of a crab, a number of jellyfishes and pelagic molluscs (Pownall 1979). European settlers commenced early fishing activities immediately after the establishment of the colony at Port Jackson in Some 1,000 people colonised Port Jackson at that time, thereby significantly increasing the demand on the area s fishing and other natural resources. This resulted in the depletion of the fish supply that had previously supported 26

49 Aboriginal and contributed to the starvation of many Aboriginal people during the winter of In response, Governor Phillip issued a general order that all fishing parties were to provide Aboriginal people with a part of their catch if approached by them (DPI NSW 1997). The earliest account of a commercial fishery operation in Australia was in 1806 when a boat-load of salted fish landed at the Hospital Wharf, Circular Quay and was recorded in the Sydney Gazette of 14 December In 1827, the first fish auctions were held in Sydney (DPI NSW 1997). One of the earliest recordings of fisheries management in Australia was the introduction of trout on 19 April 1864, 76 years after the first European settlers had arrived in Australia. Pownell (1979) concluded that brown trout were abundant throughout many streams in Tasmania and Australia, and made for a great sporting fish for thousands of fishers. However, it must be added that trout now also act as competitors with and predators of many native fish (Crowl et al. 1992). By 1865, the first serious depletions of fish stocks were recorded in waters around Sydney as a result of over-fishing and inappropriate fishing techniques. Techniques included fine-mesh nets that destroyed large amounts of fry, and stalling techniques, in which fixed nets were used to isolate shallow bays or mud flats at high tide in order to leave fish stranded at low tide (Godden Mackay Consultants 1997). During the mid to late 1800s, the inland commercial and recreational fisheries were developed and species such as golden perch (Macquaria ambigua ambigua) and Murray cod (Maccullochella peelii) were extensively fished throughout the Murray-Darling Basin and supplied to fish markets in Sydney, Melbourne and Adelaide (Kailola et al. 1993). These early catches were dominated by Murray cod, which made up 75% of river fish available at the Melbourne Wholesale Fish market in In 1899, the sustainability of the fishery was questioned, and the Fisheries Commissioners requested fishing regulations to be put into effect to ban the use of traps that spanned the entire stream and prevented free fish passage up and down the river (Kailola et al. 1993). The decline of freshwater fish stocks that were being exploited through commercial and recreational fishing continued to be a problem throughout the 1940s and 1950s. In 1953, the NSW parliament declared that a degree of management over the operations of fishers 27

50 needed to be enforced and regulations preventing the sale of undersized fish needed to be implemented to protect fishing stocks and habitats (NSW Parliament 1953). In 1958, the first general fishing licence was implemented in NSW at a cost of 1 per annum. This replaced the existing trout angling fee paid to the acclimatisation societies (DPI NSW 1997). Between 1958 and 1959, 49,350 licences were issued (Roughley 1961) Inland recreational fishing today Today, inland recreational fishing is considered to be the third most popular outdoor activity in Australia (Ross and Duffy 1995) and it is of far more importance than commercial fishing in the Murray-Darling Basin. Indeed, the commercial fishing industry was closed in the Murray-Darling Basin due to an ongoing decline in catch rates. In the Basin, freshwater recreational fishing is undertaken in nearly all the rivers, tributaries, reservoirs and wetlands, and forms a major component of the Basin's recreational and tourism activities (Lynch 1995). Angling is considered to be the main form of fishing used in Australia. This is supplemented with hoop nets to catch crayfish and crabs, spear fishing in clearer waters, and bait traps (McPhee 2008). In the Murray-Darling Basin, the main fish species that are recreationally fished are Murray cod, golden perch, freshwater catfish (Tandanus tandanus), spangled perch (Leiopotherapon unicolour), river blackfish (Gadopsis marmoratus), two-spined blackfish (Gadopsis bispinosus), brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). Murray crayfish and yabbies are also major targets for recreational fishing. There is no clear data available on the annual catch taken by recreational fishing, but the activity has an economic value estimated at over $400 million a year and at least 1.75 million people fish recreationally in NSW each year (McPhea 2008). Fisheries management in Australia has historically focussed on controlling commercial fishing harvest. The need to incorporate recreational fishing into fishing management did not fully emerge in Australia until the late 1980s (McPhee et al. 2002). McPhee (2008) suggested that this need arose due to three main factors: 1. The formation of representative recreational fishing groups. 28

51 2. An increased realisation of the significance of recreational fishing on key species, leading to a need for it to be monitored and managed as commercial fishing was (Cooke 1999; McPhee et al. 2002). 3. An increased emphasis on public consultation and general public participation in fisheries management. In Australian fishery management services, three main categories are used to support the management of fishery resources. These are research, management services and enforcement (Gooday and Galeano 2003). Gooday and Galeano (2003) summarised these categories as follows: 1. Research is used as a basis for management decisions, the creation of new management systems to meet aims such as ensuring healthy fish stocks and to assess the effectiveness of existing management techniques. Research methods include surveys, data analysis and stock assessments. 2. Management comprises three functions: adjusting management settings within existing systems, recommending amendments or additions, and administering management systems. This is worked within the Ecological Sustainable Development (ESD) principles that are described below. 3. Enforcement encompasses the surveillance of compliance of fishers with fisheries law and regulations Ecological Sustainable Development (ESD) & the Precautionary Principle Australian fisheries management has an underlying theme of ESD and has also been guided by the precautionary principle (Fletcher et al. 2005). The benefits of ESD stem from its triple bottom line approach, recognising that a sustainable economy and sustainable communities are dependent on the sustainable use of natural resources (DPI and Fisheries QLD 2007). ESD was first formally introduced to the management of Australian fisheries in 1990 by the Hawke government and with the support of public consultation (McPhee 2008). The theory of ESD originated from a report titled Our Common Future released by the UN World Commission on Environment and Development (WCED) in In the 29

52 report, the broad aims of ESD were to meet the needs of the present generations without affecting the capacity of generations in the future to be able to meet their needs. The ESD Fisheries Working Group was established in the 1990s. It recommended that all fishery management should be based on specific three to five year management plans that included legally binding management measures, public input and influence at the draft stages and in the ongoing review of the plan (EISs) (McPhee 2008). In Australia, the definition of ESD was used in the setting of objectives for the Commonwealth Fisheries Management Act In 1992, the National Strategy for ESD (NSESD) was produced by the Australian ESD Fisheries Working Groups. This outlined the core objectives of the Australian fisheries ESD, and guidelines for achieving these objectives. The three core objectives included in the NSESD (1992) were: 1. To enhance individual and community well-being and welfare by following a path of economic development that safeguards the welfare of future generations. 2. To provide for equity within and between generations. 3. To protect biological diversity and maintain essential ecological processes and life support systems. Following the implementation of the NSESD (1992), the Council of Australian Governments (COAG) declared that all future fisheries policies, programs and regulations were to take place within the conceptual framework of the ESD. Today in Australia, fisheries management still adheres to ESD principles and objectives and aims for a united approach from both a community and regulatory perspective for ESD (McPhee 2008). The precautionary principle is another framework that has had a significant influence on Australian fishery policy and legislation. This principle has been used when the environmental impact of an activity is not well understood and decision makers are unclear of the outcomes of the activity (McPhee 2008). The precautionary principle has been defined by the Intergovernmental Agreement on the Environment (IGAE 1992) as follows: Where there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. 30

53 This principle therefore does not prohibit an activity until the scientific evidence for it is clear, but instead urges that decision makers need to anticipate the possibility of ecological damage and use proactive management rather than react to it as it occurs (Stein 2000). Under the principle the activity does require an assessment of the severity of the effects that may occur (i.e. whether the effects will be irreversible), and an assessment of the degree of uncertainty that indicates the level of impact that will occur (McPhee 2008). The use of the precautionary principle in fishery management has been subjected to some contentions. In particular, although the principle works in theory, in operation it may fail due to the fact it is a values based concept. Where one person may find an action not risky, another person may find the same action too risky (McPhee 1999). As there are no rules or regulations guiding what defines a certain risk or uncertainty level, it is difficult for fishery managers to be consistent in their decisions. Further information on the precautionary principle and its use in Australia can be found in the previous papers (Deville and Harding 1997; Harding and Fisher 1999) State management Currently, in Australia the only remaining statutory authority is the Australian Fisheries Management Authority (AFMA) which was established in 1989 following an extensive review of Commonwealth fishery management policies and arrangements (McPhee 2008). State primary industries constitute the most common form of institutional structure for fisheries management in Australia. The primary industries in each state work under the relevant Acts for that state (See Tables 2 and 3). Australian state fisheries management advisors have suggested that the management of fisheries is greatly assisted by a number of key elements (Stevens 2005): 1. Sound legislation (principal Act and subordinate legislation) that provides the necessary framework for sensible decision making. 2. An overall policy that is clear and unambiguous on sensitive issues such as resource access, resource sharing, allocation, and cost recovery. This helps guide the provision of consistent advice and recommendations to governments and has the 31

54 added advantage of providing a credible basis for responding to issues raised by key stakeholder groups and the community. 3. A strategic plan for each fishery that reflects long-term sustainability and economic targets i.e. government, industry and other stakeholders know where they are going and manage towards that goal. 4. Sound consultative mechanisms that facilitate the provision of robust and constructive advice to relevant ministers. 5. Committed and quality staff to analyse and provide advice/information on sometimes difficult and complex natural resource management issues. 6. Effective administrative processes, management systems, (including appropriate delegation of authority), governance arrangements and resources aligned to the best and most timely advice possible. 7. A sensible communications strategy that ensures all stakeholder groups have ready access to information on decisions and recommendations from the Minister, DPI and consultative groups affecting their future. 8. An acknowledgement by resource users that they are involved in both the problem and the solution. Although the management of fishery resources is the responsibility of state Departments of Primary Industries (DPIs), the Murray-Darling Basin Authority has been involved in the assessment and improvement of fisheries in the Murray-Darling Basin. The Murray-Darling Basin Authority has also assisted NSW, VIC, SA and the ACT by coordinating plans, especially where cross border issues exist. In 1991, the Murray-Darling Basin Authority (formally Murray-Darling Basin Commission) implemented the River Murray Fish Management Plan to complement the activities of the state DPIs (MDBC 2003). In 2003, this document was completely revised, updated and re-implemented as the Native Fish Strategy (MDBC 2005). 32

55 2.4.5 Legislation In Australia, fishing legislation makes provision for the use of fisheries resources. The legislation also aims to conserve fish stocks, habitats and ecosystems and provide community benefits from the use of fisheries resources (McPhee 2008). Fisheries Acts have been developed at a national (Commonwealth) level and at state levels which provide management direction for Australian fisheries resources. The Commonwealth Fisheries Management Act 1991 is focused solely on the management of the Australian commercial fishing sector and is tailored towards cost effective fisheries management. The NSW and VIC Acts specifically identify objectives for recreational inland fishing. Further the NSW Fisheries Management Act 1994 is the only Australian state Act that has an objective to conserve aquatic threatened species (McPhee 2008). The Victorian Fisheries Act 1995 and the South Australian Fisheries Management Act 2007 are the only two states to have a specific objective to encourage participation in fisheries management (Table 2). Aside from fishery Acts, fishery managers also need to consider Acts that are not directly Fisheries Acts but do support fisheries production and/or aquatic resources (McPhee 2008). A list of Acts, other than fishery Acts, that impact on inland recreational fisheries planning and management is provided and briefly summarised in Table 3. 33

56 Table 2. Summary of objectives of fisheries Acts in Australian jurisdictions Source: McPhee (2008) Objectives Fisheries Management Act 1991 (Cth) Fisheries Management Act 1994 (NSW) Fisheries Act 1991 (QLD) Fisheries Act 1988 (NT) Fisheries Management Act 2007 (SA) Fisheries Act 1995 (VIC) Fish Resources Management Act 1994 (WA) Ecologically sustainable development Sharing fisheries resources and equity considerations Maximise net economic returns Encourage participation in fisheries management Provide for utilisation by the community or a specific sector Efficient, cost effective fisheries management and cost recovery Conserve fish stocks, habitats and ecosystems YES YES YES YES YES YES YES NO YES YES (as principle of ESD) YES YES (as principle of ESD) - YES YES NO NO NO NO NO NO NO NO NO NO YES YES NO YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO YES NO YES YES YES YES Conserve threatened species NO YES NO NO NO NO NO Provide community benefit/needs YES YES YES (as principle of ESD) YES YES NO NO Promote recreational fishing opportunities Increase community understanding of aquatic ecosystems Promote viable/sustainable commercial fishing NO YES NO NO YES YES NO NO NO NO NO NO NO NO NO YES NO NO YES YES YES 34

57 Table 3. Acts (non fishery) included in Australian inland recreational fishery management. Source McPhee (2008) State Acts Description of Major Functions ALL Water Act 2007 Establishes the Murray-Darling Basin Authority with the functions and powers, including enforcement powers, needed to ensure that Basin water resources are managed in an integrated and sustainable way NSW Environmental Planning and Assessment Act 1979 QLD SA VIC WA Catchment Management Authority Act 2003 Environment Protection Act 1994 Environment Protection Act 1993 River Murray Act 2003 Environment Protection Act 1970 Environment Protection Act 1986 Waterways Act 1976 Environmental Impact Assessments (EIAs), including for fishing activities Provides for the establishment of CMAs to prepare and implement action plans Relates to threatened species, environmental protection and EIAs Implements environmental protection policies to minimise environmental harm Provides for the protection, restoration and enhancement of the River Murray Environmental protection principles used to create a environmental protection legislative framework Provides for the prevention, control and abatement of pollution and environmental harm, and for the conservation, preservation, protection, enhancement and management of the environment Conservation and management of certain waters and associated land and environment and for the establishment of a Rivers and Estuaries Council and certain management authorities 35

58 2.5 Freshwater recreational fishing regulations in Australia History Fisheries management should be aimed at managing human behaviour by controlling the access to fisheries resources through fishing regulations (McPhee 2008). Fishing regulations include management tools such as size limits, daily bag limits, gear restrictions, bans on taking breeding females, closed areas and closed seasons (Table 4). If effective, such fishing regulations can help ensure healthy and sustainable fisheries for future generations. However, for them to be effective they need to be based on sound information, include values of stakeholders, be understood and supported by recreational fisher, be backed up by a significant level of enforcement effort and quantified by scientific research (Winstanley 1990). In Australia, fishing regulations have long held a place in freshwater recreational fishery management. For example, in VIC, fish size limits were introduced in 1873 and in QLD in 1877 (Hancock 1990). In WA, minimum legal weights were implemented for the western rock lobster in 1897, but converted to legal sizes later in the same year (Bowen 1980). Legal size limits and weights are among the oldest and most frequently used types of fishing regulations (Hill 1990). They set the smallest or largest size or length at which a particular species can be legally retained (Hill 1990). Size limits are easily understood and simple to apply, and as they are the same for all fishers and so ultimately affect all fishers equally, they are generally seen in this respect as being fair throughout the fishing community (Hill 1990). However, as early as 1986, Harrison (1986), made the realistic assumption that size limits alone cannot provide the control required for stock management and extra regulations such as bag limits, closed areas and seasons and protection of species began to be implemented. 36

59 Table Fishing regulations for native freshwater fish in NSW and VIC. Data sourced from DPI VIC 2007; DPI NSW 2007 Species State Fishing closure Legal length (cm) Australian bass & Estuary perch (combined) Blackfish- river Catfish, freshwater or eel-tailed Murray cod Golden perch Silver perch Crayfish - Murray Yabbies - freshwater NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC Closed season in rivers. June - August incl. Fishing prohibited. Bag, size limits, closed season apply in waters south of the Great Dividing Range. Sept - Dec incl. Closed to fishing in all western flowing waters incl. unlisted western dams. Take from waters within the Wimmera Basin. Closed season Sep - Nov incl. Closed season Sep - Nov incl. N/A N/A Fishing banned in rivers Nth Great Dividing Range excl. Wimmera Basin: Only taken from lakes and dams. Sth Great Dividing Range incl. Wimmera Basin: Taken from all waters. Closed season Sept - April incl. Fishing prohibited in notified trout waters and in Blowering Dam. Vic waters north of the Great Divide Sept April incl. No take berried females N/A N/A in listed stocked dams Bag limit/day 2, 1 fish over 35cm Lake Bullen Merri 5 Other Victorian waters (in listed western dams) 2 2 (only 1 over 100 cm) 2 (only 1 over 75 cm) in listed stocked dams 5 5 (only 1>12cm) 5 (only 1>12cm) 200 in total 20 litres whole yabby or 5 litres yabby tails 37

60 2.5.2 Basis for regulations The original reasons behind the implementation of individual fishing regulations such as size limits in Australia are today somewhat obscured by history, destroyed records and lost memories (Hancock 1990). In NSW in about 1960 many species including prawns were removed from the size limit schedule because there was no biological or marketing reason for the limits. Most of the minimum legal lengths appear to be based on empirical information from law enforcement staff since there were few biologists doing population dynamics work before 1958 (Hancock 1990). Early bag limit decisions in NSW where recorded to have been requested by fishers who provided comments when they delivered their catch to the fish markets in Sydney. This story is similar for other Australian states. For example, the following information has been provided by the DPI in QLD: In relation to the historic basis for establishing the minimum sizes no records exist and present staff are unaware of the background. It is felt that the minimum sizes were applied with size at sexual maturity, sex change and market acceptability in mind. However, no firm evidence is at hand to confirm this (Hancock 1990). In Tasmania, statements from the DPI include: No species for which sound scientific advice is currently available except flounder (Hancock 1990). These quotations were taken from questionnaires that were prepared by the Australian Society for Fish Biology s Workshop Planning Committee. They were sent out in 1989 to each Australian state, the NT, the ACT, the Commonwealth (Department of Primary Industries and Energy) and to Papua New Guinea to gain information about freshwater fishing regulations (Hancock 1990). The questionnaires sought information about the legal sizes currently in use, the purpose(s) for which they were introduced, and any associated or alternative means of control such as escape gaps, nursery closures, closed seasons and mesh size (Hancock 1990). Additional questions were also included to ascertain whether there were any prohibitions on the capture of spawning (berried) females and whether any bag limits, possession limits or catch quotas existed. Information was also sought on the basis for selecting the minimum legal size, in particular whether legal size limits were selected through the use of 'proper' scientific assessment (including any subsequent revisions), or 38

61 whether selection was made by using only selected data, such as size at first maturity and spawning periods (Hancock 1990). Table 5 shows the reasons that were listed in the survey for the implementation of minimum size limits in Australian states and territories prior to The protection of immature animals (allowing them to spawn at least once) was the favoured reason for the implementation of size regulations and made up 43% of the total purposes. This was followed by optimal marketable sizes and harvest control. Aesthetics referred to the intent to make available larger individuals, and this made up 6% of the cited reasons for size limit implementation. Interestingly, in SA at least, the size of trout was based on representations by amateur fishing interests. Economic reasons contributed only 4% of the total cited reasons, and the majority of this was in SA (Hancock 1990). Early (prior to 1989) minimum legal size limits were therefore mainly set on the size at first maturity to protect immature animals and allow animals to spawn at least once. For example, in NSW, Most estuarine fish sizes were apparently set on this [size at first maturity] basis; marketing may also have been a factor. Interestingly, the surveys also showed that the size limits that were based on size at first maturity did not have much if any scientific backing. For example, in QLD, The intent was to base regulations on size at first maturity but, except for scallops, full scientific assessments have not been made, and most sizes were in need of review (Hancock 1990). In fact, from the surveys it was clear that regardless for the reasons of minimum size limit implementation, the size limits for very few species were based on scientific assessment or biological information when size regulations were first implemented. For example, for freshwater fish species, size limits had been implemented for four species in NSW, eight in VIC, five in SA, five in QLD, two in WA and one in the NT. Of these, the only size limit that had been based on scientific assessment was that implemented for Barramundi in the NT in 1962 (Hancock 1990). In the past, maximum legal sizes have rarely been used for managing Australian fishery resources. QLD was the only state to implement maximum size restrictions by In the same year, in NSW, a maximum size limit was proposed for Murray crayfish but was rejected (Hancock 1990). The reasons for setting maximum size limits vary. For example, 39

62 a maximum size limit of 120 cm was set for the QLD groper after public complaints about large groper being killed. This limit was set due to a community emotional response to these extremely large fish (Hill 1990). On the other hand, the upper limit for Trochus niloticus in QLD was set after the larger animals were exploited heavily, because they provide most of the egg production (Hill 1990). The importance of using maximum size limits is being increasingly recognised (Birkeland and Dayton 2005). Over the last five years, maximum size limits have been used more widely in Australian fisheries management and are now mainly aimed at protecting larger egg producing animals. Table 5. Summary of purposes for the selection of minimum legal sizes in Source: Hancock (1990) Summary Protect immatures Control harvest Economic reasons Optimum market size Aesthetics VIC NSW SA QLD TAS WA NT PNG Total* * Approximate totals only; sometimes more than one species per listing. Total* Today, to yield sustainable fisheries, fishing regulations need to be combined with a holistic approach to fishery management where the management is shared by users and policy makers alike. With populations of recreationally fished freshwater species rapidly declining, some fishing regulations have become more stringent and the DPIs state that the knowledge regulations are based on has increased through scientific research and community input (DPI NSW 2007a; DPI Victoria 2007b). Fishing regulations are now preferably based on scientific evidence if it is available and also incorporate social pressures and socially acceptable aspects of regulation limits (i.e. size and bag limits) (Georgie Raby pers. comm. DPI VIC, 12 Oct. 2007). However, there are many gaps in 40

63 available information. In the absence of both scientific and social information, fisheries managers adhere to the relative state Acts, the aims of ESD and the precautionary principle, and they endeavour to make the regulatory rules as simple as possible for fishers to follow (Georgie Raby pers. comm. DPI VIC, 12 th Oct. 2007). In 1990, a number of authors (Hancock 1990; Hill 1990; Winstanley 1992) stated that, when subjected to proper scientific review, long-established minimum sizes often seem to be appropriate even though they were originally based on intuition or very basic empirical information and not on scientific information. Winstanley (1992) further stated that there was no basis for varying the size limits that had been implemented over a century previously, even though great advances had been made in fishery knowledge. He noted that indeed, in Australia, few species had actually had their size limits revised on the basis of thorough scientific assessment, and he highlighted the necessity for comprehensive and credible data as the basis for the implementation of such measures (Winstanley 1992). Minimum size fishing regulations for freshwater species have changed between 1989 and 2008 (Tables 6 and 7) From the tables it can be seen that size regulations have not been changed in the last 20 years for Australian bass in VIC and QLD, river blackfish in VIC, golden perch in SA, silver perch in QLD and rainbow and brown trout in VIC, NSW, SA, and WA. The size limits for other species such as Murray cod and catfish have been updated in parallel with increasing scientific findings on the species, increased stakeholder support and continued population declines in the past 20 years. Which of these three factors had a greater influence on the regulation changes is hard to determine. Table 8 provides an example of the range of fishing regulations that are used for native freshwater species in NSW and VIC in

64 Table 6. Minimum legal size fishing regulations for freshwater fish species prior to Data sourced from Hancock (1990) Common name Vic (cm) NSW (cm) SA (cm) Qld (cm) Tas (cm) WA (cm) NT (cm) Barramundi c x 50 d x Bass, Australian Blackfish, river 22 b Catfish Murray cod 40 b Perch, golden Perch, silver Trout, brown 25 b Trout, rainbow 25 b (b = within specified areas; c = commercial; d = recreational; x = standard at 55cm from 1 March 1991) Table 7. Minimum legal size recreational fishing regulations for freshwater fish in Data sourced DPI VIC 2007; DPI NSW 2007; PIRSA 2007; DPI QLD 2007; DPI TAS 2007; DPI NT Common name Vic (cm) NSW (cm) SA (cm) Qld (cm) Tas (cm) WA (cm) NT (cm) Barramundi Bass, Australian Blackfish, river 22 No take - No take Catfish No take Murray cod Perch, golden Perch, silver No take Trout, brown Trout, rainbow

65 Table Fishing regulations for native freshwater fish in NSW and VIC. Data sourced from DPI VIC 2007; DPI NSW 2007 Species State Fishing closure Legal length (cm) Australian bass & Estuary perch (combined) Blackfish- river Catfish, freshwater or eel-tailed Murray cod Golden perch Silver perch Crayfish - Murray Yabbies - freshwater NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC NSW VIC Closed season in rivers June - August inc. Fishing prohibited Bag, size limits, closed season south of the Great Dividing Range. Sept-Dec. Closed to fishing in all western flowing waters incl. unlisted western dams. Take from waters within the Wimmera Basin. Closed season Sep Nov Incl. Closed season Sep Nov Incl. N/A N/A Fishing banned in rivers Nth Great Dividing Range excl. Wimmera Basin: Only taken from lakes and dams. Sth Great Dividing Range incl. Wimmera Basin: Taken from all waters. Closed season Sept April Incl. Fishing prohibited in notified trout waters and in Blowering Dam Vic waters north of the Great Divide Sept April Incl. N/A N/A in listed stocked dams Bag limit/day 2, 1 fish over 35cm Lake Bullen Merri 5 Other VIC waters (in listed western dams) 2 2 (only 1 over 100cm) 2 (only 1 over 75cm) in listed stocked dams 5 5 (only 1>12cm) 5 (only 1>12cm) 200 in total 20 litres whole yabby or 5 litres yabby tails 43

66 2.6 Fishery regulation tools Fisheries managers employ a range of tools to manage fishery resources. These have been divided into three categories, namely input controls, output controls and access controls (McPhea 2008) (Table 9). Input controls include tools such as legal size limits which are measured differently for fish and crayfish species (Figs. 2 and 3), fishing gear/net restrictions and no takes on berried females. These measures control the amount of fishing effort used and the efficiency of catches through the regulation of fishing equipment. Output controls such as bag limits, possession limits, and limits on prohibited species work directly to restrict the magnitude of the total catch of an individual fisher or of a fishery. Access controls, such as closed areas and closed seasons, limit the areas and times when fishing can occur (McPhea 2008). The definitions and objectives of each of these tools are listed in Table 9. Closed or fully protected areas (no-take) are regions or reserves where some major threats can be effectively managed and are perhaps the most important tool used in biodiversity conservation globally (Kingsford and Nevill 2005). The long-term benefits of creating freshwater protected areas can far outweigh short-term costs. Freshwater protected areas can directly benefit fishers, tourist operators, tourists and agriculturalists through increased production and protection of freshwater areas (Kingsford and Nevill 2005) and can encourage education, research, and the appreciation of aesthetic values of nature (Dayton et al. 2000). Closed areas can increase protection for spawning and recruitment and for older individuals. Berkeley et al. (2004) showed that larger, older female ground-fish such as the rockfishes in the Atlantic and Pacific had higher recruitment success as they produced larvae that could withstand starvation periods for a greater duration and which grew faster than the larvae from younger, smaller fish (Berkeley et al. 2004). Indeed the protection of larger or older individuals is critical for the sustainability of species currently exploited by humans (Birkeland and Dayton 2005). Seasonal closed areas protect fish during the spawning season, enable uninterrupted spawning, limit the magnitude of yearly catch rates and conserve heavily exploited species. For example, on Georges Bank in New England the fishing closure of three areas totalling 17,000 km 2 of important ground-fish spawning and recruitment grounds resulted in a 44

67 significant reduction in the fishing mortality of reduced fish stocks and increased sustainability of ground-fish (Murawski et al. 2000). Size limits are one of the oldest methods used in fisheries management. They are generally used to protect immature fish and allow them to spawn at least once before they can be harvested, control the numbers and sizes of fish harvested and protect large breeding females. However, for minimum, maximum or slot size limits to be effective it is vital that resource managers have information about the growth, recruitment, mortality and structure of the fish population as size limits can change the dynamics and structure of fish populations such as was demonstrated in populations of walleyes in United States lakes (Brousseau and Armstrong 1987). Figure 2. Fish total length is measured from the tip of the snout on the upper jaw with the mouth closed to the tip of the tail. Source: NSW DPI (2007) 45

68 Figure 3. Murray crayfish are measured from the rear of the eye socket to the centre rear of the carapace. Source: NSW DPI (2007) 46

69 Table 9. Type of tools Input controls Input controls Input controls Input controls Output controls Output controls Output controls Access controls Access controls Input, output and access tools that can be used to manage a fishery. Fishing Regulation Minimum legal sizes Maximum legal sizes Release of berried females Gear restrictions Daily bag limits Possession limits Prohibited species Closed seasons Definition Min length of a fish unless otherwise stated. Max length of a fish unless otherwise stated. No taking of females with eggs or juveniles attached. Restrictions on fishing gear i.e. nets, lines etc. Max number of fish that one person can legally take and keep in one day. Max number of fish per person when fishing for > one day No take on protected species Areas closed permanently, temporarily or at a specific time of year Objective Protect immature fish, allow to spawn at least once. Control numbers, sizes of fish landed. Promote aesthetic values of fish. Protect large breeding females. Protect berried females, eggs and juveniles. Limit harvest level. Limit magnitude of total catch rates. Conserve heavily exploited species and species susceptible to capture. Share the catch more equitably. Reduce the illegal marketing of fish. Control harvest level. Restrict the number of fish held in possession. Reduce harm to fish. Protect threatened & endangered species. Protect fish during spawning season and enable uninterrupted spawning. Limit magnitude of yearly catch rates. Conserve heavily exploited species. Closed areas Areas closed to fishing Protect spawning aggregations Protect key nursery, fish habitat Allocate fishing areas between fishing sectors Safety reasons 47

70 In the twentieth century, the realisation that fish stocks are not infinite has bought about the introduction of a number of fishing tools. As with any changes to fishery dynamics, the implementation of any fishing regulations should be viewed with caution, and possible consequences should be considered (Hill 1990). Even small changes to a dynamic, living system with complex physical and biological processes such as a river, stream or wetland can and probably do have complex and far reaching effects. This problem is further exacerbated because the effectiveness of fishing regulations is difficult to determine. For example, introducing daily bag limits can encourage fishers to catch and keep only the larger animals. The real effect of regulations is hard to ascertain as fishers may also discard or throw back smaller animals, perhaps increasing population mortality rates and there are often many factors affecting an ecosystem, not just fishing (Hill 1990). Population models offer a method of predicting the effects of a change in a fishing regulation such as a size limit on populations (i.e. (Hall 1989; Jones et al. 1990; Potts and Todd 2005). However, for them to work effectively, they generally need considerable background biological information of the species, as well as a thorough knowledge of the fishery and the extent of compliance on behalf of fishers. Without these, population models can make far reaching predictions that in reality can be of little use. Regardless of the fishing regulations that are administered, fishers consistently act in a way that is generally not expected to occur through the implementation of fishing polices (Fulton et al. 2011). Although human uncertainties have recieved much less attention than scientific uncertainties in the past, the effects also need to be taken into account as the consequences reslting from the uncertainties can result in management outcomes which are unintended (Fulton et al. 2011). So it is essential to ensure that the remedy employed does not cause unintended repercussions elsewhere when addressing a fisheries management problem (Favier et al. 2000) Measuring fish resources through fisher surveys The success of fishery regulations is based on the information that underpins them and on the compliance with them by fishers. Monitoring of fisheries resources, such as catch and compliance rates, is vital if the effects of fishing and fishing regulations on fish stocks are to be determined. Monitoring of recreational fisheries usually involves surveying fishers 48

71 using a variety of survey techniques and can include on site and off site methods (Pollock et al. 1994). On site or face to face interviews are often conducted at boat ramps, fishing grounds or around camp grounds, and these are generally called creel surveys. (A creel was a tackle box carried by fishers.) These types of surveys are generally conducted to gain regional or site specific information for management. If well designed, they can provide excellent information on catch rates, retained catch rates, compliance with fishing regulations, reasons for fishing, levels of fishing satisfaction, and economic expenditure. Two types of creel surveys can be undertaken: roving or access point. Roving surveys allow the interviewer to move from fisher to fisher and are best undertaken in large areas with many access points to interviewees. Access point surveys can be conducted where smaller areas are surveyed and access points to fishers are limited (e.g. boat ramps) (McPhea 2008). The total harvest in creel surveys is determined by harvest rates per fisher x total effort. The independent estimates of harvest and effort rates are essential to design a robust survey (Pollock et al. 1994). To gain broader information, say at a state or national level, with a more cost effective approach, off site survey methods including mail send outs, and phone and diary surveys can be conducted (McPhea 2008). These types of surveys can be prone to potential biases as they need to rely on the accurate recall of activities that may have occurred sometime before surveys are filled out. However, they can provide useful demographic information on where fishers fish, what fish species are present and on approximate catch rates. One of the largest fishery surveys conducted to date in Australia is the National Recreational and Indigenous Fishing Survey (NRIFS), conducted in This survey used a combination of methods, including creel, phone, diary and screening surveys (household interviews) (PIRSA 2008b). It gathered information at national, state and regional levels on fishing participation rates, catch and effort rates, economic expenditure and fishers attitudes to and awareness levels of management issues (Henry and Lyle 2003). The survey provided an excellent overview of Indigenous and recreational fishing and provided the main source of contemporary information on fishing catch and participation by Indigenous people (McPhea 2008). This survey was conducted again in

72 using the same methodology as the NRIFS, to maximize data comparability and trend measurement (PIRSA 2008). Fishing records from recreational angling competitions can also provide data on fish catch rates (Gartside et al. 1999; Thwaites and Williams 1994). However, members of fishing clubs do not represent the views and attitudes of the entire fishing community (Hilborn 1985) and any trends that are recorded cannot be extrapolated to the whole fishing population (McPhea 2008) Compliance of fishing regulations As well as understanding the ecological, biological and environmental aspects of fisheries to ensure best regulations can be set, an understanding of the social aspects is also critical to ensure regulations are complied with. However, in the past, this component has largely been overlooked in Australian fisheries management (McPhee 2008). Non-compliance with regulations by recreational fishers has been documented as an ongoing problem in fishery management in countries such as Australia (West and Gordon 1994), South Africa (Brouwer et al. 1997) and the United States (Gigliotti and Taylor 1990). Brazilian fisheries have generally been managed by a top-down method with fishing communities having no input into management strategies and set fishing regulations (Castello et al. 2007). This type of management method can lead to ineffective protection of the fishing resource (Silva 2004) as a result of fishers having a low level of compliance of fishing regulations (Reis and D Incao 2000). Although the inclusion of co-management has been increasing in Brazilian fisheries, the need for a higher level of participation from resource users in management processes has been highlighted by Lopes et al. (2011). The author states that this would increase the efficiency of fishing regulations and unless this is achieved successfully the successful co-management of the system will be limited (Lopes et al. 2011). Compliance with fishing regulations can also be increased by providing fishers with incentives to promote higher compliance rates. For example, Begossi et al. (2011) conducted research with 34 artisanal fishing communities in South Eastern Brazil to gain information about the space used by fishers for fishing and about management 50

73 recommendations for the fishing resources. The authors concluded that using a comanagement approach instead of a top down approach which includes the use of fishing agreements into which fishers have input into and using economic incentives in the form of payments for environmental services could help improve the compliance of fishing regulations, management of fishing resources and the livelihoods of fishers (Begossi et al. 2011). In Australia, state government departments (Department of Primary Industries) manage the compliance strategies for fishing regulations. These departments work within the objectives of the Australian Fisheries National Compliance Strategy in developing local compliance strategies and plans to provide a consistent approach to fisheries compliance throughout Australia. The objectives of the strategy are to achieve optimal levels of compliance with fisheries laws by maximizing voluntary compliance and creating an effective deterrent against illegal activity (NFCC 2005). The state departments also enforce regulations in a number of ways. One means for this is application of extensive fines. For example, in NSW, the maximum fine for possessing illegally taken Murray cod and possessing prohibited size Murray cod is $11,000 and/or three months imprisonment for each offence. Another method involves fisheries offence reporting telephone lines. In VIC, since the inception of the offence reporting hotline (13FISH) in 2003, more than 7328 calls have been received. These calls have resulted in 424 infringement notices being issued, 81 prosecutions, the generation of 982 intelligence reports, the seizure of countless pieces of fishing equipment, and a number of significant investigations undertaken (DPI Victoria 2008). A third means involves use of patrolling officers. However, these officers cannot be placed on every river reach at all times and other fishers are not always around when illegal activity is taking place and so frequently high levels of non-compliance do occur. There is no one type of regulation that is mainly not adhered to. Fishing offences vary widely and depend on many factors such as the species fished, area fished, fishers attitudes, knowledge and reason for fishing and, of course, on the information base behind the actual regulation that has been set. In Australian states, fishing offences include undersized catches, catches of berried females, excess bag and possession limits, fishing in 51

74 closed areas or in closed seasons, fishing with excess or illegal fishing gear and removing appendages from animals such as crayfish (DPI NSW 2005; DPI NSW 2008; DPI Victoria 2007a; Fishnet 2003b; PIRSA 2008a). Recently there have also been a number of cases of non-compliance for one target species, the Murray crayfish. For example, in the Murrumbidgee River, NSW, anecdotal evidence suggests that there is currently less than 60% compliance with regulations for that species (Anonymous pers. comm. 2008). In south-west NSW, 35 fishers were fined up to $500 in a major operation enforcing new rules for Murray crayfish over the 2003 June long weekend (Fishnet 2003a). The operation, which focused on the Murrumbidgee, Edward and Murray Rivers, aimed to educate fishers about Murray crayfish and prevent illegal fishing for them. Over 1,200 fishers were checked during the three day operation by officers from the NSW Fisheries Department of Primary Industries (DPI). Fifty two undersized Murray crayfish and nine Murray crayfish in berry (carrying eggs) were seized. Of the 35 people fined, 15 were fined for not having a recreational fishing licence, and 13 were fined for possessing undersized Murray crayfish. The remainder of the fishers were fined for possessing Murray crayfish with eggs, fishing in closed waters and illegally using set lines (Fishnet 2003b). Morey (1998) found that illegal fishing in closed fishing areas of the Bunyip and La Trobe rivers accounted for similarities in catch numbers between open and closed waters. He found that overall there was no significant difference between the catch rates of crayfish from closed waters compared with open waters, nor were any differences in growth rates found (Morey 1998). This is supported by the finding that very low catch rates were observed at sites that were easily accessible such as picnic sites, roadsides and bridges (DSE 2003). There is also strong evidence that many amateur fishers do not comply with set fishing regulations (Hill 1990; Jones et al. 1990; Moore 1986). The reasons for non-compliance with fishing regulations by recreational fishers vary and can include a lack of knowledge about current regulations or a deliberate disregard (McPhea 2008). Non-compliance through disregard can be increased if fishers feel the regulations are unfair, they have not been able to have a say in the regulations, or if they do not feel they are backed by sufficient scientific information (Winstanley 1992). A disregard for regulations can also occur if the regulations do not allow fishers to catch what 52

75 they feel is their adequate portion of fish (Winstanley 1992), if fishers think they will not get caught or if there is enough incentive for black market trade. From conversations with numerous freshwater researchers or scientists from around NSW, QLD, SA and VIC it seems that even these people do not always comply with the regulations if they feel they will not be caught. Amazingly a she ll be right attitude persists even in a group of people who work directly to try to prevent the declining fish species. If we refer to the VIC fishnet public forum (Fishnet 2007a; Fishnet 2007b), a large number of statements from fishers can be found that disagree with current fishing regulations or refer to non-compliance of fishing regulations. The following comments from the Fishnet public forum demonstrate this: The new laws are BS and they will only encourage more illegal methods. Who do the do gooders and tree huggers think they are? Making these decisions in an office a million miles from a river. I guess one good thing I do agree on is the new size limits etc. Now that is good thinking. But as for the rest of the laws - piss off. Really very few people setline legally and there will be no difference made to your fishing. The majority that setline illegally with more than their four and no name tags etc etc, will continue to do the same thing regardless. They were breaking the law before and will be breaking the law in the future. Supportive comments, however, are also voiced in such forums. For example, the following comments were made to the changes to NSW fishing regulations in June 2007 (Fishnet 2007b): Finally, some reason shown, some progress made. If we were in the pub, it'd be beers all round. Finally a step in the right direction. They look a bloody fair set or rules to me. Over the past decade, state fisheries departments (DPIs) have been increasingly involving fishers, the community and other stakeholders in the decision making about, and implementation of, new fishing regulations to ensure the sustainability and viability of future fisheries resources (DPI NSW 2007b). For example, some new changes to NSW 53

76 freshwater recreational fishing regulations were introduced in September 2007 (Table 10). These changes resulted in the minimum legal catch length for Murray cod being increased from 50 cm to 55 cm on 1 December 2007, followed by a further increase to 60 cm on 1 December 2008 (DPI NSW 2007b). According to NSW DPI, these changes reflected the findings of scientific environmental assessments, the National Recreational and Indigenous Fishing Survey (2000/01), the Palmer Inquiry into illegal fishing, advice from expert committees of anglers and public submissions (DPI NSW 2007b). The general public was invited to voice their opinions on the proposed modifications to size limits, bag limits and fishing methods. A total of 75,000 discussion papers were distributed across NSW and more than 3,300 public submissions on the proposed changes were returned. These submissions were reviewed by expert fisher committees and the final set of bag and size limit changes were supported by the Minister s key stakeholder advisory councils (the NSW Advisory Council on Recreational Fishing (ACoRF) and the Seafood Industry Advisory Council (SIAC)), before being implemented. To ensure fishers were aware of the changes, NSW DPI undertook an extensive public advisory campaign over a three month period. This campaign included signage, brochures, stickers, on-site advice from Fishcare volunteers and information on DPI s website (DPI NSW 2007b). 54

77 Table 10. Changes to NSW freshwater fishing regulations, September All changes are indicated in bold. Source NSW DPI (2007) Species Fishing Closure Size Limit Bag Limit Australian bass and estuary perch Zero bag limit in rivers and estuaries from 1 June to 31 August each year. Catfish Fishing prohibited in all (freshwater or eeltailed) and unlisted western western flowing streams dams. 1 fish longer than 35cm in streams. 30cm (in listed western dams) 30cm (in all other waters) *2 in total. 1 fish longer than 35cm in streams. 5 (listed western dams) 2 (all other waters) Eel (long finned) - 58cm 10 in total Murray cod Zero bag limit September November inclusive. From 1 Dec 2007, MLL will 2. Only 1 over be increased to 55cm, followed 100cm. by a further increase to 60cm on 1 December River blackfish Fishing prohibited in all waters. 0 0 Unlisted native species (except invertebrates) N/A N/A 10 in total State departments are now more than ever including community and fishers views in changes made to fishing regulations. The main way that this is achieved is through peak bodies that represent recreational fishers who advice government and fisheries management on policy and policy changes. For example in NSW the main advisory body is the advisory council on recreational fishing (ACORF) and in VIC the Victorian recreational fishing (VRFish) is utilised. However, from this section of the review it can be seen that there are still a significant number of fishers who do not support current regulations and/or do not comply with them. These fishers can be perfectly aware of the fishing regulations but choose to disregard them. The above example of community involvement in the new NSW regulations set in June 2007 provides an example of one of the reasons why this may be occurring. Fishers in this process were not consulted about their opinions as to what the regulations should be changed to but as to whether they agree with the proposed changes or not. Perhaps a different approach is needed. One possibility is a more holistic approach 55

78 where all stakeholders provide information on the species and all stakeholders are included in the initial decision making stages when deciding what changes could be made. But in an approach such as this it is difficult to determine at what point the line needs to be drawn between where fishers comments are taken on board and used to drive decision making and where decisions are made based on scientific evidence. It seems that new fishing regulations now cannot be implemented without the support of fishers who are willing to voice their opinions. Fishing regulations either need to be designed with the assumption that non-compliance will occur and therefore need to have more stringent parameters attached to them (i.e. higher minimum sizes and lower maximum sizes, lower bag limits) or fisheries management needs to be redesigned so that fishers support the regulations and comply with them to a greater degree. It would not seem fair for complying fishers if fishing regulations were increased because some fishers do not comply with them. In fact, increasing fishing regulations for this reason could very well lead to non-compliance by fishers who currently do comply. Further consideration is by fishery managers is required if presently declining regulated species are not to be lost from river sections all together Are the current regulations working? Decline of native species Australian rivers, lakes, wetlands and streams are home to approximately 300 species of freshwater fish (Lintermans 2007) and to over 120 crayfish species (Taylor 2002). In the past 200 years, many of these freshwater species have suffered serious declines in abundance and distribution due to natural events such as prolonged droughts as well as to human exploitation and intervention (Lintermans 2007; Wager and Jackson 1993). Human induced events include over-fishing from the late 1800s to the mid 1900s; the use of and runoff from toxic agricultural chemicals in the early 1900s; introduction and spread of exotic species, which act as both competitors and predators of native species, in the mid 1900s; and the construction of weirs and commencement of river regulation, which led to a change in environmental flows, blocked migration passage and the decline in survival and recruitment rates of larvae and juveniles, in the mid 1900s (Ball 2001) (Fig. 4). These factors, bar the use of toxic chemicals, are serious obstacles that even today are associated with declining populations of native freshwater species. 56

79 European settlement Settlement in Murray-Darling Basing Over-fishing Toxic chemicals Locks and Weirs Introduced species Figure 4. Influences leading to declined native fish species in Australia. In comparison to marine fish species, declines in native freshwater species have become increasingly harrowing. For example, in NSW, 6% of freshwater fish species have been listed as threatened under the Fisheries Management Act 1994 whereas less than 1% of marine fish species are considered threatened (NSW EPA 2001). In the Murray-Darling Basin, it has been estimated that native fish populations are at 10% of pre-european levels, and introduced fish such as carp make up more than 80% of the fish population at many sites (Lintermans 2007). Although no freshwater fish species are known to have become extinct in Australia since European settlement (ASFB 2000), there has been some localised extinction of native species. In addition, approximately 40% of the Australian fish fauna is now considered of conservation concern (Lintermans 2007). Despite widespread recognition of the issue, the decline of native fish species has not been extensively studied at a national level, and data do not exist for the whole of Australia (Ball 2001). In addition, the success rate of current fishing regulations has not yet been validated, even for species that are still declining in abundance and distribution (DSE 2003). In the Murray-Darling Basin, over-fishing has contributed to the decline of many native aquatic species such as Macquarie Perch (Macquaria australasica) (Cadwallader and Gooley 1984; Harris and Rowland 1996), Murray Cod (Maccullochella peelii) (Rowland 1989) and Murray crayfish (Euastacus armatus) (DSE 2003; Geddes 1991; Geddes et al. 57

80 1993). Each of these species has been extensively fished in the past. State fishing closures and fishing regulations now exist for each of these species but the effects of illegal fishing and the effectiveness of current fishing regulations is yet to be determined. For example, Murray crayfish is still thought to be declining in both distribution and abundance in NSW where it is legally fished. It has suffered a considerable reduction in range over the last 50 years and due to its life history and limited dispersal capability is at continued risk from over-fishing and population fragmentation (Asmus 1999). Currently, there is limited baseline data on the biology and habitat requirements of Murray crayfish in both the Murrumbidgee and Murray River systems (Asmus 1999) Are the current regulations working? The Murray crayfish Fishing for Murray crayfish is now banned in both SA and the ACT. Fishing regulations for this species were first implemented in NSW and VIC in 1989 (See section 9). In 1999 NSW Fisheries increased the legal size of Murray crayfish from 8 cm to 9 cm occipital carapace length (OCL). As with past regulation decisions, this decision was based on a perceived decline in crayfish numbers based on fishers reports and not on clear scientific evidence (Asmus 1999). Today, even with the implementation of fishing regulations such as size limits, bag limits, closed seasons and protection of berried females in NSW and VIC, the simple act of catching crayfish may undermine the value of these regulations (Hill 1990). The extent of mortality suffered by under-sized individuals, berried females or by their attached eggs or juveniles, during capture and release needs to be assessed whenever fishing regulations are a major part of a management strategy. All mortality of animals that are just below the legal limit is particularly deleterious because these animals would have had a high chance of reaching reproductive age (Hill 1990). Further, the open fishing season for Murray crayfish is during the time that females are sexually active, lay eggs and nurse eggs and juveniles. Although there is a ban on taking berried females at any time, berried females are still caught in the nets and then generally released. There is therefore a strong probability that eggs and juveniles carried by females are disturbed or killed. The effects of catching and releasing under sized crayfish and berried females has not yet been examined. To this 58

81 day, there is no knowledge of the effects of catch and release on Murray crayfish populations. Introducing a ban on taking berried females could also prove problematic in the long-term. As a result of not being able to take larger berried females, fishers target larger males. This means that fewer males than females make up the remaining population and that, of that population, males are generally smaller than the females. For example, in the Murrumbidgee River, a greater proportion of female Murray crayfish were found with increasing recreational fishing pressure (Asmus 1999). The maintenance of suitable sex ratios has been an objective in the management of the southern rock lobster in VIC and Tasmania (Winstanley 1990). A ban on taking berried females resulted in a female biased sex ratio, and in 1988 the minimum legal length for females was lowered in order to increase the exploitation rate of females relative to males (Winstanley 1990). Previous studies have not examined the effects of a biased sex ratio on Murray crayfish populations or long-term sustainability. This raises strong concerns for the reproductive and recruitment success of this species. These concerns are further heightened with current knowledge gaps such as whether larger females will they mate with smaller males and the effects of smaller, younger parents on recruitment successes and population diversity. A further potential limitation in the current fishing regulations may be the effect of size limits on fecundity, recruitment success and overall population dynamics. Larger bodied animals, such as Murray crayfish generally grow slowly and have higher fecundity at older life stages. The number of eggs produced by a female of such species is directly proportional to the size of the female. Therefore the larger females generally produce more eggs (Hill 1990) and the fecundity of a mature female can be said to increase with length (Walker 1990). Interestingly, the current size regulations protect smaller animals but provide limited protection for Murray crayfish when they reach their reproductive stage and for older, larger animals. Further, these larger bodied, slow growing animals are biologically designed to have higher death rates during their younger life stages, and lower mortality with increased size and age. The rationale of these size regulations seems to go against Murray crayfish morphology and biology. Perhaps in order to provide better protection for Murray crayfish, size limits should be adjusted to protect the larger, older 59

82 reproducing adults which naturally have a lower mortality rate, higher fecundity rate and generally higher recruitment success. Such issues need to be addressed through further research. The current effects of fishing and the fishing regulations on Murray crayfish populations are largely unknown Murray crayfish (Euastacus armatus) background Over 120 of the world s approximately 540 freshwater crayfish species are endemic to Australia (Taylor 2002). Australia s crayfish belong to the family Parastacidae which includes all freshwater crayfish from the southern hemisphere. Despite having a diverse crayfish fauna, information on the ecology and biology of most of these species is lacking (McCarthy 2005). McCarthy (2005) has recently summarised some of the Euastacus species on which published information exists. This includes E. bispinosus (Honan 1998; Honan and Mitchell 1995a; Honan and Mitchell 1995b; Honan and Mitchell 1995c), E. spinifer (Merrick 1997; Turvey and Merrick 1997a; Turvey and Merrick 1997b; Turvey and Merrick 1997c; Turvey and Merrick 1997d; Turvey and Merrick 1997e), E. kershawi (Morey 1998), E. hystricosus (Smith et al. 1998), E. urospinosus (Borsboom 1998) and E. armatus (Asmus 1999; Geddes 1990; Geddes 1991; Geddes et al. 1993; Lintermans and Rutzou 1991; Versteegen and Lawler 1996). Australia s crayfish species occupy a variety of habitats ranging from riparian zones to cool mountain streams and include species commonly referred to as yabbies, marron and lobsters (Ball 2001). The Murray crayfish is the largest of 43 species of spiny freshwater crayfish in the Euastacus genus and the second largest freshwater crayfish in the world. It has the widest distribution of any of the spiny crayfish (members of the genus Euastacus and Astacopsis). The species predominantly resides in the main channel of a river; uses clay banks, woody debris, deep holes and boulders as shelter; and has a small home range (McCarthy 2005). Important habitat parameters include flowing water, water temperatures below 27 o C, moderate salinities (under 16 parts per thousand) and well oxygenated water (Gilligan et al. 2007). Murray crayfish traditionally supported Indigenous Australians with a food source throughout the Murray Darling Basin (Horwitz and Knott 1995). In the 1800s and early 1900s this iconic species was widespread throughout the River Murray and many of its 60

83 tributaries in NSW, SA, VIC and the ACT. The natural distribution encompassed around 12,500 km of waterways within the catchments of the Murrumbidgee, Murray, Mitta Mitta, Kiewa, Ovens and Goulburn Rivers, with the distribution ranging from near Murray Bridge in SA, upstream to over 700 m altitude (Gilligan et al. 2007) Conservation status In the twentieth century Murray crayfish supported small commercial fisheries in NSW and SA. Professional fishers in SA noted a decline in Murray crayfish stocks in the mid 1950s, and by 1965 the species was no longer commercially targeted in SA (Geddes et al. 1993). Declines in the distribution, abundance and average size of Murray crayfish were also noted in NSW, VIC and the ACT by commercial and recreational fishers and researchers from the 1950s onwards. In NSW, concerns over the sustainability of commercial fishing led to an end to the commercial fishery for Murray crayfish in 1990 (McCarthy 2005). Since the 1950s the species has suffered a dramatic decline in both abundance and distribution and is now considered very rare or locally extinct in the Murray River downstream of Mildura and is reportedly very rare in several lowland river reaches (Geddes 1990; Horwitz 1990a; Horwitz 1995). In 1989, a fishing ban was placed on Murray crayfish in SA and they were declared protected due to stock depletion through over-fishing. Murray crayfish have not been recently recorded in SA. In 1991, a survey of Murray crayfish in the Murrumbidgee River in the ACT found that numbers were low and being affected by overfishing (Lintermans and Rutzou 1991). In 1991, the species was declared protected in the ACT and the fishery was closed to allow stocks to recover (Lintermans and Rutzou 1991). In the ACT, the fishing ban has had limited success, with Murray crayfish numbers slightly increasing and most of the increases being at a single site (Ball 2001). The species is now listed as having conservation significance nationally, internationally and in three of the four Australian states in which it resides (Table 11) (McCarthy 2005). At a national scale, Murray crayfish have an indeterminate conservation status due to the lack of knowledge regarding the species at the time of the implementation of the status in 1990 (Horwitz 1990a). Murray crayfish were again listed as internationally indeterminate following a review of their status in 1994 by the IUCN (Groombridge 1994). Horwitz (1995) subsequently suggested the national conservation status be raised to threatened. 61

84 Following re-assessment in 1996 (Crandall 1996), the IUCN listed Murray crayfish as vulnerable (VU A1ade) on the IUCN Red List of Threatened Species. However, a review of the IUCN categorisation for the species using the Ramas Red-List software program (Akçakaya and Ferson 1999) resulted in a listing category of data deficient (Clark and Spier 2003). Due to the variability in abundance among different regions within its range, the conservation status of Murray crayfish is not consistent across Australian states. In SA, Murray crayfish are protected under the Fisheries Act 1982 and although are listed as endangered, are now considered to be locally extinct downstream of Mildura (Geddes et al. 1993). In the ACT, they are listed as vulnerable under Section 21 of the Nature Conservation Act 1980 (Protected Invertebrate schedule 1 of the Nature Conservation Act 1980, Gazette No. S85, 28 Aug 1991). Due to a reduction in its range and abundance, the species is now listed as threatened in VIC under the Flora and Fauna Guarantee Act 1988 (McCarthy 2005). In NSW, Murray crayfish are still found in parts of the River Murray and its tributaries, so the species is not considered to warrant a threatened species status (Gilligan et al. 2007). Instead, they form part of the Lower Murray River Endangered Ecological Community, listed under the NSW Fisheries Management Act 1994, which includes the Murray River and its NSW tributaries between the Hume Weir and the SA border, and the entire Murrumbidgee catchment downstream of Blowering and Burrinjuck Dams (DPI NSW 2002). In December 2001, the range of aquatic species in natural water bodies in the lower Murray and Murrumbidgee catchments were listed as the Lower Murray River Endangered Ecological Community by the Fisheries Scientific Committee (Recreational Fishing Trust 2002). The listing was based on the conservation status of the aquatic ecology and not on what activities (fishing or other) could or could not take place there. The Fisheries Scientific Committee made an interim order to allow recreational fishing to continue while a species impact statement (SIS) was prepared to determine the impact of recreational fishing. The SIS was prepared and community consultation occurred. As a result, changes to fishing for Murray crayfish were implemented from 1 December 2002 with an aim to 62

85 ensure that continued fishing was sustainable and did not have a significant impact on the endangered ecological community (Recreational Fishing Trust 2002). Murray crayfish continue to be a popularly targeted species for recreational anglers in both VIC and NSW (Gilligan et al. 2007). In NSW, recreational fishing for Murray crayfish is permitted within the Endangered Ecological Community boundaries, and the threatened status is more aligned to protect the species from habitat disturbance (Gilligan et al. 2007). Fishing regulations have been implemented in both states because of the continuing decline in crayfish numbers (Ball 2001). However, the effectiveness of these regulations in sustaining long-term crayfish populations remains to be proven. Table 11. Conservation status of the Murray crayfish. Source: McCarthy (2005) Region Status Act Victoria Threatened Flora and Fauna Guarantee Act 1988 South Australia Protected Fisheries Act 1982 New South Wales Forms part of the Endangered Ecological Community of the Lower Murray River Catchment. Fisheries Management Act 1994 (Part 3 of Schedule 4) Fisheries Management Amendment Act 1997 Australian Capital Territory Vulnerable Nature Conservation Act 1980 (Section 21) Nationally Indeterminate* Threatened** Horwitz (1990) Horwitz (1995) Internationally Vulnerable 2000 IUCN Red List of Threatened Species *Indeterminate is defined as Taxa known to be Endangered, Vulnerable or Rare but where there is not enough information to say which of these three categories is appropriate (Horwitz 1990a)). **Horwitz (1995) reviewed and updated the status of Murray crayfish to Threatened. In Australia, action plans for threatened freshwater species are generally prepared by state government fisheries departments. In SA, despite being protected, to date, no action or recovery plan has been developed for Murray crayfish. Similarly, in NSW, the species is listed as a component of an endangered ecological community across much of its range but 63

86 also does not have any such plans implemented or prepared. However, recently, several key threatening processes to aquatic ecosystems that are relevant to the conservation of Murray crayfish have been declared in NSW (Gilligan et al. 2007). In VIC, an action statement has been developed for both Murray crayfish and Glenelg spiny crayfish (Van Praagh 2003). The long-term conservation objectives for Murray crayfish in VIC, as outlined in the Victorian Action Statement for Murray crayfish, are to guarantee that the species can survive, flourish and retain their potential for evolutionary development in the wild (van Praagh 2003). A specific action plan for Murray crayfish has been developed in the ACT (ACT Government 1999). Further, a new multi-species recovery plan for the ACT has incorporated Murray crayfish recovery actions (ACT Government 2006). Recreational and commercial fishing pressure on depleted stocks and illegal fishing has been listed as a key threat to native fish management in the Murray-Darling Basin in the Murray-Darling Basin s Native Fish Strategy (NFS) (MDBC 2003). The vision of the NFS is to ensure that the Basin sustains viable fish populations and communities throughout its rivers (MDBC 2003). The goal of this strategy is to rehabilitate native fish communities in the Basin back to 60 per cent of their estimated pre-european settlement levels after 50 years of implementation (MDBC 2003). In 2005, the importance of Murray crayfish in the Murray-Darling Basin was recognised and this species was included as part of the fish community covered by the Murray-Darling Basin Commission s Native Fish Strategy (NFS) (Gilligan et al. 2007). In the NFS, Murray crayfish fall under driving action 5: Protecting Threatened Native Fish Species (MDBC 2003). This driving action has been implemented to help achieve objectives 6, 10 and 13 of the NFS. These are to devise and implement recovery plans for threatened native fish species, manage fisheries in a sustainable manner, and ensure community and partner ownership and support for native fish management (MDBC 2003). This will hopefully improve the future coordination of management and knowledge generation for Murray crayfish across the Basin (Gilligan et al. 2007) Knowledge Murray crayfish are the basis of a popular recreational fishery in many areas of the southern Murray-Darling Basin (Sanger and King 2002). Yet despite the social importance of this 64

87 species, much ecological and biological data is lacking and so effective management remains a complex issue. Gilligan et al. (2007) recently summarised the published and unpublished data available for this species. They found that the majority of data was available only as unpublished departmental manuscripts, theses, secondary references to unpublished data, or in items published outside of peer-reviewed scientific journals (Gilligan et al. 2007). Gilligan et al. (2007) revealed that limited data was available on nomenclature, morphology, systematics, distribution, population genetics, habitat requirements, environmental tolerances, movement and migration, daily and yearly activity patterns, diseases and parasites, breeding biology, growth, age and mortality, and the population size structure and abundance of several populations. However the data available for each of these parameters was not extensive Local knowledge To date, the most comprehensive information available about the Murray crayfish recreational fishery remains to be that collected by O Connor between 1982 and 1984 (Gilligan et al. 2007). O Connor (1986) distributed 510 logbook surveys to obtain data on the locations, methods, timing, effort, size composition, catch and harvest of Murray crayfish fishers in NSW. O Connor also circulated questionnaires that were aimed at identifying the motivation behind fishing and the attitudes towards potential future regulation options. At the time of the surveys, fishing regulations for Murray crayfish in NSW were limited to restrictions on taking berried females and no size, bag or closed season restrictions were in place. O Connor (1986) found that 25% of fishers fished once or twice per year, 25% fished three to four times, 25% fished five to seven times and 25% fished more than seven times per year. Seventy four percent of fishers fished on weekends and this was mainly undertaken from a boat. Seventy nine percent of fishers used only hoop nets, while 6% used only traps. The majority of fishers concentrated their fishing effort between Albury and Tocumwal, and Echuca and Tooleybuc on the Murray River, and from Wagga Wagga to Darlington Point on the Murrumbidgee River. Seventy two percent of fishing was undertaken in May and June (during what is now the current open crayfish fishing season in NSW), 18% between July and August, and 10% in September and April (the current closed season). A 65

88 total catch of 28,165 Murray crayfish was recorded during the two year study period. O Connor (1986) recorded an average catch per unit effort of 0.36 crayfish per hoop net lift in the Murray River and 0.42 crayfish per hoop-net lift in the Murrumbidgee River. He noticed that the catch per unit effort was greatest between Barmah and Nyah on the Murray River and between Wagga Wagga and Darlington Point on the Murrumbidgee River. Sixty six percent of the catch was taken by 25% of the fishers, thereby representing a non-evenly distributed catch per fisher (O Connor 1986). Interestingly, O Connor (1986) found that even without size regulations in place, fishers reported releasing 91% of smaller crayfish (< 65 mm OCL). He also found that fishers were releasing 42% of the non-berried crayfish (< 80 mm OCL) and 3% of non-berried females (> 80 mm OCL). Sixty six percent of fishers thought of crayfishing mainly as a source of relaxation and occasion to spend with friends, while 21% went crayfishing to get food and 9% crayfished for sport (O Connor 1986). Thirteen years after O Connor s study was undertaken, Asmus (1999) conducted a recreational fisher s survey in NSW to obtain data on the level of understanding of recreational fishing regulations. One hundred and twenty nine fishers were interviewed. Of these, only 5.4% were unaware of the regulation to return berried females and 32.2% of fishers were unaware of the legal number of hoop nets allowed to be used. Interestingly, less than 50% of fishers were aware of the minimum legal size limit, the daily bag limit, the total possession limit and the presence of waters closed to recreational fishing. Many fishers (65.2%) were under the impression that the legal size limit was less than 90 mm (Asmus 1999). These results suggest that fishing regulations were at the time not sufficiently advertised or that people did not have access to areas where they were advertised Knowledge gaps Although Gilligan et al. (2007) demonstrated that more data is available on Murray crayfish than perhaps previously thought, current knowledge gaps still exist on the distribution, ecology, biology and habitat requirements of this species. Furthermore, information on the current effects of fishing pressure and the current regulations on the distribution, abundance, genetic diversity, length frequency ratios and sex ratios is currently very scarce 66

89 but also vital for future management of the species. For regulations to be effective, compliance is required by fishers. Currently a large gap exists to decipher fishers values, attitudes, support and compliance with current fishing regulations. Below I have listed the knowledge gaps that have been raised in a number of studies (ACT Government 1999; Barker 1990; Clark and Spier 2003; Geddes et al. 1993; Gilligan et al. 2007; Horwitz 1990b; Potts and Todd 2005; Sanger and King 2002; Van Praagh 2003). As some of the knowledge gaps listed in some dated studies have to date been filled, I have only listed those knowledge gaps that have not already been filled. Biology Reproductive rates. Fecundity/size relationships. Fitness of eggs and juveniles/size of parents relationships. Growth/age relationships. Oxygen requirements. Dietary requirements, preferences. Effect of moulting on females reproductive capacity. Ecology Factors that affect recruitment success in wild populations. Ecological role of crayfish in the ecosystem. Impact of burrowing behaviour and use of burrows at different life stages. Impact of burrowing behaviour and use of burrows at different flows / seasons. Migration and habitat requirements Migration and movement behaviour of berried females, especially movement between large major river channels where the adult populations reside, and smaller order tributary streams. Seasonal use of microhabitats. Spatial variability in biology and ecology of Murray crayfish (e.g. size at first breeding). Current status of Murray crayfish throughout their entire range. 67

90 Quantifying the population size of Murray crayfish. Tolerance of different life stages to different salinity, temperature and oxygen levels. Juveniles Biology. Habitat requirements. Dispersal, migration and movement behaviour. Survivorship. Size at sexual maturity. Growth/age relationships. Human impacts Effects of habitat modification on Murray crayfish populations. Effects of eutrophication and salinity. Impacts of river regulation on burrowing behaviour. Impacts of river regulation on abundance and distribution. Effect of land use practices and sedimentation. Tolerance of agricultural chemicals/pesticides. Impact of introduced species (e.g. trout, redfin, carp). Possibility for reintroduction into sites in SA at sites downstream from weirs. Fishing pressure Effects of fishing pressure on distribution. Effects of fishing pressure on abundance. Harvesting rates. Effects of fishing pressure on genetic diversity. Effects of fishing pressure on length frequency ratios. Effects of current fishing regulations on sex ratios. Implications of a biased sex ratio on sustainability of the population. Efficiency of current fishing regulations on long-term population survival. Population models for Murray crayfish to assist in determining sustainable levels of recreational fishing. 68

91 Local knowledge Fishers attitudes to current fishing regulations. Values of fishers. Fishers support of current regulations. Fishers views on what regulations should be. Fishers compliance with current regulations. 2.7 Recreational fishing regulations for Murray crayfish History of fishing regulations Over-fishing has been recognised as a threatening process for the Murray crayfish in NSW (Geddes 1990), VIC (DSE 2003), SA (Horwitz 1990a; Lintermans and Rutzou 1991) and the ACT (Lintermans and Rutzou 1991). Concern for Murray crayfish arose in the 1980s as a result of reports by fishers of a marked decrease in crayfish sizes and abundance (Horwitz 1990b). Prior to 1989 there was no size limit on Murray crayfish and fishers were permitted to retain all crayfish captured regardless of size. Murray crayfish have been protected in SA and the ACT since 1989, where total Murray crayfish fishing closures have been put into effect. Despite continued declining numbers in NSW and VIC, Murray crayfish are still a popularly targeted recreational fishing species using hoop nets (Fig. 5) in both these states and have been highlighted as one of the top four fished species in the lower Murray and Murrumbidgee Rivers in NSW (Sanger and King 2002). However few studies have examined the response of crayfish to over-fishing (DSE 2003). In 1989, fishing regulations were implemented for Murray crayfish of a minimum size limit of 8 cm and a no take on berried females in NSW and a no take on berried females in VIC (Table 12). Interestingly, a maximum size limit was also proposed in NSW in 1989, but was rejected due to insufficient evidence in its favour and the disapproval of the proposal from fishers (Hancock 1990). The main reason behind the implementation of these fishing regulations was to protect immature and berried females. The reasoning was to allow females to spawn at least once, and to prevent the take of females in berry. The minimum size regulation set in NSW of 8 cm was not based on scientific evidence but instead on the observed length at which 69

92 females reach first sexual maturity as reported by fishers. At this time, many fishers argued that stricter fishing regulations should not be effected until governments proved that an issue or problem would arise if regulations remained as they were (Walters and Martell 2004). No further regulations were therefore implemented until By 1995, fishers had noticed further declines in Murray crayfish distributions and abundance, and further fishing regulations were implemented that included minimum size limits in VIC, maximum numbers of crayfish caught per day in both NSW and VIC, and a maximum number of crayfish in possession in NSW (Table 12). Since the late 1990s, most fishery management agencies have been given the power to resist such demands due to the adoption of the precautionary principle (Dayton 1998; FAO 1995; United Nations General Assembly 1996). In December 2002, Murray crayfish were listed in the Lower Murray River Endangered Ecological Community in the Murray and Murrumbidgee Rivers in NSW. As a result, a reduction in the bag limit of Murray crayfish was implemented from 10 to 5 (with only one greater than 12 cm permitted) and a closed season from September to April was put into effect in NSW waters (Recreational Fishing Trust 2002). In the following year, The Flora and Fauna Guarantee (Taking or Keeping of Spiny Freshwater Crayfish) Order 1/2003 established the introduction of the same closed seasons in VIC waters (DPI Victoria 2003; DSE 2003). The annual closed seasons prohibited the harvest of Murray crayfish from the 1 September to 30 April each year. These were implemented to contribute to the sustainable management of Murray crayfish populations by providing additional protection for legal sized female Murray crayfish to maintain their long-term breeding capacity (DPI Victoria 2003). In VIC the closed seasons were also introduced to avoid the transference of fishing effort to that state from NSW waters. As the closed season had already been introduced into NSW, fishers were crossing the border to fish for crayfish in VIC waters. Therefore the VIC DPI decided that matching closed seasons for Murray crayfish would stop the pressure on VIC stocks (DPI Victoria 2003). 70

93 Figure 5. Illustration of a hoop net used to catch Murray crayfish. 71

94 Table 12. Key Murray crayfish fishing regulations (1989 to 2008)* Year Fishing Regulation NSW VIC SA ACT 1989 Length Min Max 8cm - Bag limit/day - - Limit/possession - - Closed season - - Berried female No take No take 1995 Length Min Max 8cm - Fisheries Department of Conservation and Natural Resources, Melbourne; Anon. (1996): Recreational cm - Bag limit/day Limit/possession 20 - Closed season - - Berried female No take No take 2003 Length Min Max 9cm Only 1>12cm 9cm - Bag limit/day 5 10 Limit/possession 10 - Closed season Sept April Sept April Berried female No take No take 2007 Length Min Max 9cm Only 1>12cm Bag limit/day 5 5 Limit/possession cm Only 1>12cm Closed season Sept April Sept April Berried female No take No take 2008 Length Min Max 9cm Only 1>12cm Bag limit/day 5 5 Limit/possession cm Only 1>12cm Closed season Sept April Sept April Berried female No take No take Protected Protected Protected Protected Protected Protected Protected Protected Protected Protected *Table sources: Lynch, P. (1995): Freshwater Guide 1995: Guide to NSW Inland Fishing Laws. NSW Fisheries, Sydney; Anon. (1995): Freshwater Recreational Fishing in New South Wales: A Brief Guide with New Trout Rules. NSW Fisheries, Sydney; Anon. (1995): Recreational Fishing in South Australia. Primary Industries South Australia, Adelaide; Anon. (1995): Victorian Recreational Fishing Guide. Victorian

95 Fishing in Queensland Freshwater. Queensland Boating and Fisheries Patrol, Brisbane); NSW DPI (2007); VIC DPI (2007). **NSW Crayfish: All crayfish must be landed whole. Tails and claws must not be detached in, on or adjacent to the water. It is an offence to keep crayfish with eggs or to remove those eggs. **VIC crayfish: Crayfish must be landed in carcass form. No possession of female spiny freshwater crayfish in berry (with eggs) or with young attached, no removal of eggs, spawn, setae or fibres from any female spiny freshwater crayfish Size limits Minimum size limits Minimum size limits are the oldest and most common tools used in managing fishery resources. Currently the minimum legal size for Murray crayfish in NSW and VIC is 9 cm OCL. This has been set to allow reproducing females a chance to breed at least once before they can be caught. However, as not all females would have reached a reproductive age by the time they are 9 cm, the current size limits limit the reproductive output of the population. Gilligan et al. (2007) have suggested increasing the minimum size limit to 10 cm OCL, which would help ensure that almost 100% of females would have reached sexual maturity by the time they can be caught. A 10 cm size limit was also recommended (Morison 1988; Sanger and King 2002). This would increase the reproductive output of the population and would also increase the average size of individuals within the population (Gilligan et al. 2007). The suggestion of setting maximum size limits in NSW first occurred in 1989, but was rejected due to insufficient supporting evidence. It was not until almost 20 years later, in 2007, that a maximum size limit was implemented in NSW and VIC. This consisted of the legal taking of only one Murray crayfish per fisher that was over 12 cm OCL in length per day. Although this may seem like a reasonable recommendation, it is well known that most species have an exponentially higher fecundity (number of eggs produced) with increasing size. Indeed, McPhea (2008) stated that if all other factors were kept constant, larger females could contribute disproportionately to the reproductive output of the entire population. Further, it has been found that older fish can produce larvae that have significantly higher survival potential than that of younger fish (Birkeland and Dayton 73

96 2005; Bobko and Berkeley 2004). These factors have not been studied for Murray crayfish. However, in terms of sustainably managing the species it would seem sensible to assume that some, if not all, of these factors may also be relevant to Murray crayfish. These suggested changes have been gazetted and implemented for action in 2013 by NSW Fisheries. Further, if one reach of river is fished by 20 fishers over a three day long weekend, between them they could take 60 Murray crayfish that are above 12 cm in length. This does not seem to equate to strong protection measures for these larger animals as Murray crayfish do not move large distances and a population can be reduced significantly if large numbers are taken. Perhaps an extra absolute maximum limit, above 12 cm, also needs to be introduced for all crayfish caught (i.e. a slot limit). The lack of knowledge of the above variables, coupled with the fact that Murray crayfish are extremely slow growing and can take up to 9 years to reach sexual maturity (Honan and Mitchell 1995b; Turvey and Merrick 1997b) seems to point to a need for additional regulations regarding maximum legal sizes for Murray crayfish. Indeed the protection of larger or older individuals is critical for the sustainability of species currently exploited by humans (Birkeland and Dayton 2005) Closed areas Closed or protected areas are regions where some major threats can be effectively managed and are perhaps the most important tool used in biodiversity conservation globally (Kingsford and Nevill 2005). The long-term benefits of creating freshwater protected areas can far outweigh short-term costs. Freshwater protected areas can directly benefit fishers, tourist operators, tourists and agriculturalists through increased production and protection of freshwater areas (Kingsford and Nevill 2005). Today, a number of sites along river reaches and streams in NSW and VIC are closed to recreational fishing for Murray crayfish (Fig. 6; Table 13). In NSW, the protected areas consist of both river and stream reaches that are closed to all types of recreational fishing and those that are specifically intended to protect populations of Murray crayfish (Gilligan et al. 2007). In NSW, a total of 1,084 km of stream are closed to crayfishing (Fig. 6). Included in these reaches are areas m upstream and downstream of weirs, some lowland river reaches and notified trout waters in upland areas (DPI NSW 2007a). In VIC, 74

97 Murray crayfish are protected by default in three closed fishing areas, totalling 16 km in length, as these are closed to all forms of recreational fishing (Gilligan et al. 2007). Murray crayfish are also protected in the 678 km of stream within their natural range in SA and the 163 km of stream within their natural range in the ACT. Combining the total areas of recreational fishing closures that protect Murray crayfish throughout these three states and territory, a total of approximately 16% or 1,941 km of their natural distribution is protected (Gilligan et al. 2007). Although these legislative protection strategies are in place, anecdotal evidence from fishers sggestes that the species are reportedly still in decline. Interestingly, following some brief conversations with fishers (pers. comm.), it seems that a number of people want to see the implementation of total closures of areas or more protected areas assigned to allow Murray crayfish a chance to return to more sustainable population levels. This will be further investigated through this current research project. Figure 6. Waterways closed to recreational fishing for Murray crayfish. closed waters; smaller closed waters of several hundred metres. Source: (Gilligan et al. 2007) 75

98 Table 13. Closed areas to Murray crayfish fishing in NSW and VIC. Data sourced from (Tilbrook 2006). River Site Specifics Murray River Hume Weir Downstream for 130 metres, upstream from Seven Mile Creek junction at Talmalmo to headwaters of Murray River. This includes any tributaries and creeks. Rufus River Yarrawonga Weir 50 metres upstream and 201 metres downstream of the weir. Yarrawonga Weir Yarrawonga Weir to the Tocumwal Road bridge closed to all forms of fishing during Sep, Oct and Nov. Torrumbarry Weir Near Euston 400 metres upstream and downstream of the weir, including Lock Lagoon. 800 metres of each side of inlet channels leading to, and including, Lake Benanee and Dry Lake; also Benanee Creek, Taila Creek, Washpen Creek and intake channel from the Murray River. The whole river, from the Murray River to Lake Victoria. Edward River Near Deniliquin From Tuppal Creek downstream to the Wakool River. Murrumbidgee River Tumut River Near Moulamein From the western boundary of Benjee State Forest No. 534, downstream to the eastern boundary of Berambong State Forest No Near Moulamein Near Mathoura Near Mathoura Burrinjuck Dam Billabong Creek, from the Edward River upstream to the western boundary of Ten Mile Reserve (Rural Lands Protection Board Reserve No ). From the Murray River at Picnic Point downstream to its junction with Gulpa Creek. Tuppal and Gulpa Creeks, from the Murray River downstream to the Edward River. Downstream for a distance of 640 metres. 50 metres upstream, downstream of Gogeldrie, Yanco Creek, Berembed, Redbank, Maude, Balranald weirs. Tumut River including Jounama Pondage and Talbingo Dam upstream of the stored waters of Blowering Dam. Tumut River and its tributaries upstream from its junction with the Murrumbidgee River to the Blowering Dam wall. 800 metres downstream from Jounama Dam spillway gates in Blowering Dam. 76

99 Closed seasons Closed seasons are applied primarily to protect species during the spawning period. Currently, the fishing season for Murray crayfish opens on 1 May and closes on 31 August each year in NSW and VIC. These dates align with times that the majority of fishers used to fish before regulations were introduced (O Connor 1986). It seems that the closed season was implemented because something had to be done, but it might not contribute significantly to sustaining viable populations of Murray crayfish. For mature Murray crayfish, mating activity commences at the beginning of May each year. After mating, females carry their eggs underneath their tail from May until hatching occurs in October (O Connor 1986; Van Praagh 2003). The dates for the open season therefore seem ineffective for a number of reasons. First, although closed seasons are meant to protect spawning species, the times of open fishing for this species correspond directly with their breeding time. Second, not all mature females would have deposited eggs by 1 May, so a percentage of females that have not yet had a chance to deposit eggs will actually be caught targeted. This is particularly problematic as there is generally a high level of fishing effort early in the season (Barker 1990; Rich and Johnstone 1988). Indeed, in the VIC public Fishnet forum, fishers have reported a significant decrease in Murray crayfish present just two weeks after the opening season commences compared to the first weekend of opening. Skurdal et al. (1997) suggested that the opening of the crayfishing season should be delayed until at least 15 May to allow all mature females to mate and develop eggs prior to the commencement of fishing. They stated that this would increase the reproductive output of the population, and therefore also increase the population growth rate and sustainability of the fishery (Skurdal et al. 1997). Third, although there is a no take policy for berried females, the effects of handling crayfish on eggs and juveniles is unknown and the current open season allows for extensive handling of berried females. Not adhering fishing regulations to the recruitment processes including spawning and egg deposition timing, is poor management practice in any fishery, but allowing recruitmentover-fishing of late maturing, long-lived species will usually have more significant longterm impacts than will recruitment-over-fishing of short-lived highly fecund species that reach maturity within one to two years. The population size of a short-lived highly fecund 77

100 species can build up much quicker than that of a long-lived species which does not reach reproductive maturity until some nine years, such as the Murray crayfish (Walker 1990). Thus, the current timing of the closed seasons for Murray crayfish needs to be investigated further No take of berried females A no take regulation on berried females requires the immediate release of berried female crayfish (Fig. 7). There has been little research to show that this method is actually effective in managing crayfish or other species populations. The regulation may limit the harvest rate of crayfish, but it may also have a dramatic effect on the sex ratios of a population and put significantly higher pressure on male crayfish. The impacts on population dynamics and sustainability of populations from such effects are currently unknown (McPhea 2008). Note: Differentiating between male and female crayfish is achieved by examining the location of their gonopores (Fig. 8). Figure 7. Murray crayfish eggs 78

101 a b Figure 8. Location of gonopores in male (a) and female (b) Murray crayfish. 2.8 Consistency between regulations across NSW and VIC In Australia, the history of freshwater fishing regulations such as closed areas is generally a story of good intentions not carried through. The Australian (Commonwealth) government is responsible for international treaty obligations, cooperating with the states, local government and regional resource management planning bodies (Kingsford and Nevill 2005). However, Australia s three-tiered three government ernment system places most resource management responsibilities with the states and territories (Kingsford and Nevill 2005). Generally, freshwater management decisions are made and implemented at the level of individual state DPIs where decisions are made solely for that state and not on a tri-state tri basis throughout the Murray Murray-Darling Basin. This means that management such as fishing regulations can and generally do vary between the states. Since the introduction of fishing regulations for Murray crayfish in NSW and VIC in 1989, they have not been consistent consisten across the two states.. This can lead to misunderstandings of the regulations by fishers and can lead a decrease in compliance rates. In 2008, the four key recreational fishing regulations minimum size limit, bag limit, closed season and no take on berried females were consistent between NSW and VIC IC (Table 14 14). However, several other Murray crayfish fishing regulations were not consistent between betw the two states (Table 79

102 15). One of these differences that may place a higher stress on NSW crayfish is a higher possession limit in NSW (Gilligan et al. 2007). With a higher possession limit, it would seem obvious that fishers would keep more crayfish in possession for longer to ensure they get the largest or best individuals from their catch. Keeping a higher number of crayfish in possession for longer periods could also increase the stress experienced by crayfish and it could result in lost appendages where crayfish are kept in small containers. A difference in the permissible dimensions of hoop nets (Figure could affect the catch rate and size of individuals caught (Table 15). Studies conducted by O Connor (1986) demonstrated catch efficiency differences due to mesh size and hoop diameter, but no differences were found relative to mesh drop or the use of bait holders. O Connor (1986) found that a mesh size of 13 cm was most efficient at capturing Murray crayfish. Conveniently, this is also the maximum mesh size that is permitted in NSW. There are no restrictions on mesh size in VIC. However, given the presence of a minimum size limit, crayfish caught with a smaller mesh size than 13 cm would not be able to be taken as they would be under the size limit. Therefore, the presence of a mesh size in NSW does not seem to contribute much to the sustainability of Murray crayfish. However, where fishers do not comply with minimum size limits, having a maximum mesh size limit is beneficial as this is easier to control than individual crayfish caught and results in undersized individuals being less likely to be caught and taken. O Connor (1986) also found that a hoop diameter of 0.7 m was the most efficient at catching Murray crayfish, while hoop diameters of 0.6 m, 0.9 m and 1.2 m caught 62%, 30% and 22% fewer individuals, respectively, than the 0.7 m diameter hoop net. Despite the differences in permitted hoop net sizes between NSW and VIC, both these states have maximum hoop net sizes that are within the most efficient hoop net size. So it seems that these regulations may be redundant (Gilligan et al. 2007). Given that O Connor (1986) found that hoop net depth (drop) was not significantly related to catch, the differences in the permissible hoop net drop between the states are not significant and in fact the regulation may also be redundant in both states (Gilligan et al. 2007). Hand collection of Murray crayfish is permissible in VIC but not in NSW (Table 15). This may have a strong impact on Murray crayfish populations in circumstances where Murray 80

103 crayfish leave the water to escape environmental disturbances. An example of Murray crayfish leaving the river was recorded in the Barmah-Millewa Forest in , during black-water events (McKinnon 1995). The final regulation that differs between the two states is prohibiting the mutilation of Murray crayfish (Table 15). In NSW, the regulations state that it is illegal to remove the claws, legs, head and/or tail in, on or adjacent to waters. This protects the entire animal and does not allow any appendages to be removed. However, VIC regulations state that crayfish must be landed in carcass form. The VIC recreational fishing regulations define carcass as: The body of a crayfish which is not cut in any way other than to remove one or more legs or claws, or is not mutilated in any way other than the absence of one or more legs or claws (Gilligan et al. 2007). Therefore, this regulation actually legalises the removal of one or more legs and claws from crayfish before they are released. Claws are essential in defence and feeding, and the removal of these appendages from undersized or berried female crayfish that are required to be returned to the water can cause detrimental impacts to the individuals. Gilligan et al. (2007) have recommended that inconsistencies in the regulations between NSW and VIC should be reviewed and where possible resolved. Further, in the future, it would be beneficial if states that were considering changes to their regulations liaised with other relevant states in order to ensure consistency across borders. Table Murray crayfishing regulations that are consistent across NSW (Tilbrook 2006) and VIC ( Source: Gilligan et al. (2007). Fishing regulations Closed season A four-month fishing season exists for the taking of Murray crayfish (May 1 - August 31). Size limit Berried females Daily bag limit The minimum size limit is 90 mm OCL. All berried females and females carrying young must be returned to the water immediately, regardless of size. The daily bag limit is 5 crayfish per person per day, of which only one individual can be larger than 120 mm OCL. 81

104 Table Murray crayfishing regulations that are inconsistent across NSW (Tilbrook 2006) and VIC ( Source: Gilligan et al. (2007). NSW Fishing regulations VIC Fishing regulations Possession limit Possession limit of 10. Possession limit of 5. Number of hoop nets per licensed fisherman A maximum of five labelled hoop nets in all waters. A maximum of five labelled hoop nets in all waters except Lake Eildon and Lake Dartmouth. Here, 10 hoop nets are permitted. Dimensions of hoop nets Collection by hand Lines Mutilation Hoop nets must not exceed a maximum diameter of 1.25 m, maximum drop of 1 m and minimum mesh size of 13 mm. Not recognised in the fishery regulations. A single attended line, or up to four set lines are permitted. Hooks are allowed. Illegal to remove the claws, head and/or tail in, on or adjacent to waters. Hoop nets must not exceed a maximum diameter of 0.77 m and maximum drop of 0.5 m. There are no mesh size limitation in VIC. Can also be collected by hand. Limit of 10 bait lines. Hooks are not allowed. Must land them in carcass form. 2.9 Summary Fisheries management has progressed from managing at a single species level with only managers involved to managing at an ecosystem level with the involvement of all stakeholders. In recent years, there seems to have been significant progress in the inclusion of freshwater research and the principles of ESD and co-management in fishery management in Australia. However, these changes do not seem to be reflected in fishing regulations for dwindling native species such as Murray crayfish. For Murray crayfish, this review reveals a number of problems with current regulations. These include biological, ecological and environmental problems, as well as social problems. Although there is limited information on this species, regulations even at this stage could be adjusted to improve the sustainable management of Murray crayfish. In this research project I will examine these issues and aim to gather information to help guide the sustainable management of Murray crayfish populations. 82

105 Chapter 3 Is the Murray crayfish (Euastacus armatus) fishery sustainable? Insights from recreational fishers Abstract Freshwater recreational fishing has long been a way of life in Australia. However, the current sustainability of native freshwater species is being questioned. Murray crayfish, an iconic native and highly valued recreational fishing species in the Murray-Darling Basin, Australia, have been declining in abundance and distribution for the past 100 years. There is uncertainty about exact causes, but declines have been related to habitat degradation, regulation of rivers and over-fishing. The current sustainability status of Murray crayfish remains questionable. Interviews were conducted with recreational fishers to explore their knowledge, values and experiences related to fishing for Murray crayfish (Euastacus armatus) with an aim to answer the following questions: What values, attitudes and norms do fishers associate with fishing for Murray crayfish? What biological information do fishers hold about Murray crayfish? What are fishers perceptions of current fishing regulations, compliance levels and the sustainability of Murray crayfish? And, what possible alternative management actions do fishers perceive are required to help ensure a sustainable Murray crayfish fishery? Thirty semi structured interviews were undertaken with fishers along the Murray River, NSW. Fishers generally went fishing to gain the experience of catching and eating crayfish and spending time with family and friends. Interviewees thought that Murray crayfish populations were not sustainable, perceived compliance rates with fishing regulations were low and catch rates were likely exceeding sustainable levels. Recreational fishers suggested that changes were required to current fishing regulations (increase in the MLL and in the duration of the closed season, a decrease in bag and net limits and a total fishing closure for three to five years), regulation enforcement methods and community education methods to achieve long-term sustainability of Murray crayfish. 83

106 3.1 Introduction Maintaining sustainable fisheries is often a complicated and difficult task for fisheries managers due to gaps in the available knowledge and the complexity of fishing resources. Biological information required to ensure sustainable fisheries is often examined from a scientific perspective. This process can be costly from both an economic and time outlook. Fisher local ecological knowledge (LEK) including fishers knowledge, values and experiences, can provide detailed information on the biology and ecology of species and requirements needed to help ensure the sustainability of resources, but is often not collected and generally underutilised in the management process. Detailed information about fisher LEK and its use in fisheries management is provided in Chapter 4 and the following references (Akers et al. 1979; Baigòn et al. 2006; Bray and Schramm 2001; Ebbers 1987; Johannes 1998; Johannes et al. 2000; Rochet et al. 2008; Silvano and Begossi 2012; Silvano et al. 2006; Silvano and Valbo-Jørgensen 2008). The aim of sustainable fisheries management is to use, conserve and enhance resources so that ecological processes, on which life depends, are maintained, and so that the total quality of life can be increased (see, for example, National Strategy for Ecologically Sustainable Development, Council of Australia Governments, 1992). However, increasing human populations and resource needs, as well as improved technology, have led to increased fishing effort and the geographic expansion of fishing. Together, these trends have contributed to the decline of world-wide marine and freshwater fish stocks at an unprecedented rate, and they have contributed to increased complexity of fisheries management (Henry and Lyle 2003; Ramsay 1991; Sims and Southward 2006). Indeed, most of the world s fisheries are being over-exploited (AFMA 2008b; APFIC 2006). For example, the FAO (1999) stated that most rivers, reservoirs and lakes have been fished to levels beyond their optimum. Thus the sustainability of fisheries world-wide has become a major concern. The growing concern about the state of the world s fisheries has led to an increased interest in the management of people and fisheries in marine environments (Alverson 2002; Hilborn 2007; Johnson and van Densen 2007; Neis et al. 1999). The importance of fishing and catch data for effective management of fisheries has been acknowledged by management 84

107 agencies across the globe. In commercial fisheries, fishers are generally obliged to provide fishing and catch data to assist the monitoring of compliance with regulations. These data are also used to monitor stock changes (Gerdeaux et al. 2006) and to facilitate the engagement of fishers in management and research. Until the 1970s it was generally perceived that commercial fisheries took the greater part of the total fishery catch and that recreational fishing did not make a large impact (Ramsay 1991). Therefore, compared to commercial fishery management, until recently there has been little effort to gather data from recreational fishers to monitor the impact of fishing. However, it is now evident that the growth of recreational fishing is greater than was previously anticipated (Ramsay 1991). For instance, in Australia, recreational fishing is the third most popular outdoor activity (Ross & Duffy 1995, Henry & Lyle 2003). In the Murray-Darling Basin, recreational fishing is undertaken in virtually all of the rivers and reservoirs and forms a major part of the Basin s recreational and tourism activities (Lynch 1995). Studies such as the National Recreational Fishing Survey (Henry & Lyle 2003) have provided information on the extent of recreational fishing in Australia. However, little published information is available about the knowledge, values and experiences of recreational fishers in relation to the sustainability and management of freshwater fisheries. Fishers often have a broad and detailed knowledge of fisheries stemming from ongoing and often extensive interactions with the environment in which they fish (Johannes 1981; Ruddle 1994) and through interactions with and observations of other fishers (Grant and Berkes 2007). Previous literature suggests that fisher LEK can complement scientific information (Johannes 1998; Johannes et al. 2000), improve decision making (Baticados 2004; Berkes and Folke 1998), and provide practical knowledge that can be used to improve fishery management (Bergmann et al. 2004; Silvano and Begossi 2005). Begossi (2008) identified four aspects of fisher LEK that are relevant to fishery management. These were knowledge of the use of the fishery and its natural resources, the location and space where fishing is undertaken, the behaviour of other fishers, and the ecological and biological knowledge fishers have of fish species (Begossi 2008). Detailed background information about fisher LEK has been provided in the introductory section of Chapter 4. 85

108 Face-to-face interviews with fishers can provide large amounts of detailed data on fishing practices and fish behaviour (Neis et al. 1999). For example, previous studies using personal interviews with fishers have provided detailed information on seasonal and directional fish movements and stock structure (Hutchings 1996), local changes in fish abundance (Hutchings and Myers 1994) spawning areas (Ames 1998) and mortality rates (Hilborn and Walters 1992). The use of fisher LEK in decision making processes is likely to enhance acceptance of the legitimacy of management decisions and increase fisher commitment to conservation and management aims (Castello et al. 2009; Fletcher 2005; Wilson et al. 2003). On the other hand, if adequate engagement is not achieved, management decision making and outcomes can be less than optimal. For example, Dobbs (2000) linked over-fishing in New England to managers failing to implement appropriate fishing regulations because of strong pressure from fishers who were not adequately engaged in the management process and did not trust stock assessments by scientists (Dobbs 2000). In concert with environmental changes, the introduction and spread of alien species, and over exploitation, most Australian inland native fish species have undergone dramatic declines in both number and distribution (Allen et al. 2002). Current predictions are that only 10% of pre-european fish populations are left and that without intervention this is likely to fall to 5% in the next half century (MDBC 2005). The future sustainability of iconic native freshwater species such as Murray cod Maccullochella peelii, catfish Tandanus tandanus, trout cod Maccullochella macquariensis and Murray crayfish Euastacus armatus has been undermined. Such native species were over-fished by commercial and recreational fishermen in the latter half of the nineteenth century when the fishery must have seemed inexhaustible (Allen et al. 2002; Geddes et al. 1993). In the southern Murray-Darling Basin, Murray crayfish were commercially fished in NSW and SA from the mid 1800s to the mid 1900s and were reportedly sent to markets in Sydney and Melbourne in great numbers (Geddes et al. 1993; McCoy 1867). In NSW, the Murray crayfish commercial fishery peaked at over 15 tonnes per year in 1955 and in Due to declines in numbers, Murray crayfish were rarely marketed by 1982 (O Connor 1986) and the commercial harvest of this species was 86

109 closed in 1987 (Gilligan et al. 2007). Although most commercial fisheries of native species are now closed in Australian inland waters, strong recreational fishing pressure still exists for long-lived prized species such as Murray cod and Murray crayfish. To help protect these valued resources, fisheries managers have had to expand and improve their management strategies. Fishing regulations are now widely used to ensure healthy and sustainable fisheries for future generations (DPI NSW 2007a; DPI Victoria 2007b)(NSW DPI 2007; VIC DPI 2007). Regulations generally control fixed and variable inputs such as the number of boats, fishing gear, fishing times and outputs such as size and quantity of catch (Hatcher et al. 2000). For example, fishing regulations including size limits (minimum 9 mm OCL, only one over 12 mm OCL), bag and possession limits (5), closed seasons (May August) and areas, and a no take on berried females are in place for Murray crayfish in NSW. The effectiveness of such fishing regulations is largely dependent on the knowledge base behind the regulations and on the compliance of fishers (Nicol et. al. 2004). To my knowledge, there are no published or current studies assessing fisher LEK, values and experiences related to Murray crayfish management, the fishing regulations associated with them or sustainability of the species. Indeed, only two unpublished studies by O Connor (1986) have documented cases where recreational fisher surveys have been used to gather information about the Murray crayfish recreational fishery in NSW (outlined in Literature Review, Section 2.6.8). These data are now dated due to the implementation of additional fishing regulations for Murray crayfish (e.g. minimum legal limit (MLL), bag limit, possession limit, net limit and closed season and waters) (Gilligan et al. 2007). Since the implementation of these additional fishing regulations in 1998, Asmus (1999) conducted surveys with 129 recreational fishers in NSW to explore recreational fisher behaviour and the extent of fisher understanding of recreational fishing regulations for Murray crayfish. He found that the majority of fishers were aware of the no take rule for berried females and net limits, but more than 50% of those interviewed were unaware of the regulations concerning minimum legal length (MLL), bag limit, possession limit and closed waters (Asmus 1999). These results suggested that there was a lack of publicised information about fishing regulations for Murray crayfish (Gilligan et al. 2007). 87

110 As part of the scoping study for Murray crayfish, Gilligan et al. (2007) compiled an overview of traditional ecological knowledge (TEK) on Murray crayfish from interviews held with Aboriginal communities throughout the Murray and Murrumbidgee river catchments in southern NSW. These authors gathered historic information about the methods, timing, areas, and seasonal patterns of harvesting Murray crayfish for food (Gilligan et al. 2007). The study revealed that Murray crayfish were generally harvested during the cooler months when they became more active, harvesting was undertaken in a geographically spaced manner to ensure that localised crayfish populations were not overfished or put under fishing pressure, limited numbers were captured to provide food solely for the family group, and berried females were consistently returned to the water (Gilligan et al. 2007). These methods suggest a sustainable harvesting of Murray crayfish. Today, with anecdotal evidence from recreational fishers suggesting continued declines in the abundance, distribution and size of crayfish caught (Horwitz 1990a; Horwitz 1995), there is much debate between managers, fishers and scientists about the appropriateness and effectiveness of current fishing regulations and what future management steps should entail. This raises questions about whether the fishery is sustainable under current regulations. It is difficult for decision makers to tackle these questions due to the large knowledge gaps associated with the biology and ecology of Murray crayfish and requirements needed to help ensure sustainability of the species. In this chapter, I explore some of these knowledge gaps by conducting interviews with recreational fishers to explore their knowledge, values and experiences related to fishing for Murray crayfish. Through this method, I aim to answer the following questions: What values, attitudes and norms do fishers associate with fishing for Murray crayfish? What biological information do fishers hold about Murray crayfish? What are fishers perceptions of current fishing regulations, compliance levels and the sustainability of Murray crayfish? What possible alternative management actions do fishers perceive are required to help ensure a sustainable Murray crayfish fishery? 88

111 These questions were examined by drawing on data from 30 interviews undertaken with recreational fishers in NSW. I anticipated that the data would provide vital information about fishing regulations that could be used in the management of Murray crayfish and other species. 3.2 Methods Participant selection The number of participants used in the study to reach saturation was estimated using the methods outlined by Morse This included factors such as the quality of the data, scope of the study, number of interviews per participant and the design of the interviews and study (Morse 2000). The 30 participants for this study were indentified during field 49 site visits. Recreational fishers who were fishing for Murray crayfish at river reserves and fishing locations within a 230 km reach of the River Murray between the Hume Weir (36º S, 147º E) and Yarrawonga Weir (36º S, 145º E), NSW (Fig. 9) during the 2009 open crayfish fishing season (May August) were approached and asked to participate in an interview. This river reach was used as it is a popular recreational crayfish fishing area (D. Potter, NSW Department of Primary Industries, pers. comm.). Interviews were conducted on boat ramps, river banks, on boats and at camping grounds adjacent to river sites. Interviews were conducted during different times and locations to gain variation in the sample of fisher informants (Seidman 1998) and achieve representation across the range of river access points, jurisdictions, week/weekends and days/nights (time of fishery effort) (Pollock et al. 1994). During the 49 site visits, 14 site visits were conducted over a weekend, 35 during week days, 11 were conducted after dark and 38 were conducted during daylight hours. All fishers at each site were asked to be interviewed, and all accepted the invitation. 89

112 Figure 9. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray between Hume Weir and Yarrawonga Weir in which fisher interviews were undertaken in Fisher interviews Thirty interviews were undertaken to ascertain recreational fisher knowledge of Murray crayfish population dynamics and associated fishing regulations. Semi-structured interviews (see explanation below) were used to facilitate a flexible approach that could explore viewpoints raised by participants. This method enabled one off interviews to be undertaken over a period of time and permitted depth and richness in the information obtained. The purpose of the research was explained to all informants prior to interviews taking place. Consent for participation and tape recording was obtained before each interview. The duration of the interviews varied between 20 and 70 minutes. Where possible, interviews were taped and subsequently transcribed. One informant preferred not 90

113 to be recorded; in this case, extensive notes were taken during and immediately after the interview following the framework developed by Spradley (1980). An interview schedule was designed on the basis of six key questions (Table 16), as identified from issues prevalent in the research literature. The interviews were undertaken in a conversational manner between the interviewer and informant. The interviewer attempted to guide the conversation rather than lead it, to incorporate the key questions, and, where necessary, to use probes (Table 16) to verify interpretations of responses provided by interviewees (see Brittan 1995; Kvale 1996). Table 16. Key points for fisher interview schedule and associated probes. Key points for fisher interview schedule Fisher values Biological knowledge about Murray crayfish Sustainability of crayfish fishery Knowledge and views on fishing regulations Perceived compliance rates Future management of crayfish fishery Data analysis Probes Why do you fish? What do you like about fishing? Views on fishing for future generations? Preferences for fishing? Where and how often do you fish? Where found? Habitat and environmental preferences? Growth rates? Is fishery sustainable? Why yes/no? How can it become sustainable? What are current regulations? History of regulations? Views on current regulations? Current compliance rates? Changes in compliance rates? Role of different stakeholders in management? Changes required? If yes, then detail? For fisher interviews, the audio recordings and notes were transcribed verbatim to a spreadsheet. The interview transcripts were entered into and analysed using the software package QSR NVIVO 8. Using the software package, all data were thoroughly examined, and themes associated with fisher values, crayfish biology (i.e. growth, size, sex, habitat) 91

114 (Holdich 2002), fishing regulations, compliance rates, and sustainability and future management of Murray crayfish were identified and coded (King and Horrocks 2010). These data were thoroughly searched for all divergent views to form a rich description of different factors related to the themes. Evidence in the form of selected quotes was provided to illustrate themes and support key findings. 3.3 Results Of the 30 informants, 25 were male and five were female. The age of informants ranged from 25 to 65 years (mean 41 ± 7.1 S.E.). The amount of time that informants had spent fishing ranged from their first fishing trip to fishing for over 50 years. Six of the informants were visiting from other areas (> 150 km away), 16 lived within 80 km of the fishing site and eight lived within 30 km of the area they were fishing in. Occupations of informants were grouped according to categories used by Kerkeni et al. (2006). There were eight professionals (doctor, pharmacist, teacher, professor), two clerical, two house wife s/husbands (women or men without employment outside of home), and 18 others (services, agricultural work, non-qualified employees, fisheries, day-labourers, not classifiable) (Kerkeni et al. 2006). Six dominant themes related to the Murray crayfish fishery emerged from analysis of the interview data. These themes emerged from all interview topics. The themes included fisher values, biological knowledge, sustainability, fishing regulations, perceived compliance rates, and future management. Some quotes are chosen to illustrate the data Fisher values, attitudes and norms Fishers values as to why they went fishing for Murray crayfish were mainly associated with the experience of catching and eating crayfish and spending time with family and friends. Fifty three percent of fishers commented that they went fishing for Murray crayfish because they enjoyed the thrill of catching large crayfish and being able to eat them (RF1 Thrill of the catch and the feast of crayfish, also great buzz to score a big crayfish, RF3 Like catching them to eat, RF26 Like a feed of crays ). Fishers (47%) also commented that they went fishing as a way to spend time with family and friends (RF7 After all, isn't it about getting away lighting a fire and talking shit with your mates, RF14 Just fish for 92

115 recreation, something to do, get away for a weekend with mates and a few beers, RF23 Used to go for the long weekend with 8 or so guys. Was a great weekend, hang out with mates, big piss up and a good feed of crays ). Seventy three percent of fishers attitudes towards changes that needed to be made to address the issues of low numbers of crayfish were that people should show respect for the river and fish in different ways (RF13 There s no respect for the river like there once was; now they eat females and their eggs, RF17 Need to change people s values and behaviour so they take one or two to taste and let the rest go. Respect the river and crays like we used to, RF30 Numbers are so low because people don t respect the river like we and our parents did; need people to stop raping and plumaging the resource; take only what they need for a taste and start respecting the river again ). Forty seven percent of fishers suggested that prior to the introduction of fishing regulations, the social norm was to return berried females and small crayfish to the water (RF11 Twenty five years ago, we used to catch heaps of crayfish, day or night. It was an unspoken rule that everyone put the berried females back and also put back any small ones they found. Didn t need regulations back then, people weren t as greedy and were smarter. Realised that if you took them all, then there d be none left, RF14 Fishers plan is first in best dressed and bugger the rest. Not like it used to be before regulations where everyone would put the babies and mothers back, RF22 Before regulations, old blokes never took berried females, but took ones that had a tail as big as thumb; now they take everything ) Fisher local ecological knowledge The majority of fishers (80%) suggested that Murray crayfish live in colonies mainly in outside bends, deeper holes and areas with muddy banks, timber and grass sedges. Most fishers (73%) stated that although the water needed to be moving it did not necessarily need to be fast flowing water and most of the Murray crayfish that they caught were in the slower flowing, deeper outside bends. One fisher commented on the size of Murray crayfish in relation to their age (RF22 The old fishers used to say that the bigger crays, around 17cm, were around 50 to 100 years old ). This fisher did not identify whether he 93

116 agreed or disagreed with this comment. The biological knowledge of Murray crayfish as supplied by recreational fishers during the interviews is summarized in Table 17. Table 17. Recreational fisher LEK of Murray crayfish in NSW (fisher n = 30). Habitat preferences Community structure Juveniles Outside bends Live in colonies Only find them close to banks Deep holes Moving water (does not need to be fast flowing) Slow flowing deeper outside bends Presence of timber, cumbungi and muddy banks Require muddy banks or rocks for burrowing More active in less light conditions (cloudy days, dusk, dawn, night) Sustainability Dominant crayfish present Found before sandbars Need muddy sand, wood, cumbungi Time of year Soft in summer Inactive in summer Berried females caught in summer Fishers provided information on whether they thought the Murray crayfish fishery was sustainable and why, what the reasons were for the sustainability level they perceived and what they thought could be done to improve the sustainability of the fishery. A high percentage (87%) of fishers commented that the Murray crayfish fishery was not sustainable. Almost all fishers (96%) who said they did not think the fishery was sustainable provided comments to support their claims. The three most common comments were that fishers had been getting low catch rates (87%), that they were mainly catching undersized crayfish (73%) and that they were generally catching only large females and smaller undersized males (78%). Fishers observations related to low catch rates and low numbers of crayfish were generally based on their personal fishing experiences in which they caught few or no crayfish (RF11 Used to fish quite often, now there s no crays left, RF15 Nothing around left to catch and the regulations make it too hard. Maybe go once a year. People don t cray anymore here, no 94

117 crays, been fished out and rules making it too hard for them, can t be bothered, RF21 We didn t catch a cray on weekend, there s no crays around anymore, all been fished out ). Fishers comments referring to the size and sex ratios of Murray crayfish were related to catching undersized Murray crayfish (RF13, Most of the males seem to be just under legal size, RF19 Used to catch heaps around here, big ones too. Now there s only the small ones left and not much of them around either ); and only catching large females and smaller undersized males (RF11 There are now a lot more bigger females than males, RF15 There are only large females and small males left now, RF21 All been fished out. Now nothing but small males and large females ). Fishers stated that the reasons they thought the Murray crayfish fishery was not sustainable were that there was high fishing pressure and a decrease in Murray crayfish numbers over time. Comments from fishers on a decrease in crayfish numbers generally referred to their perceptions of gradual decreases in abundance and distribution over the last 10 to 20 year time period (RF1 My family had been fishing around here for 100 years. There used to be heaps of crayfish here. You could see them walking around everywhere. Now not nearly the numbers that there once was, RF2 The numbers of crays are really dwindling under the current rules, RF7 Watched decrease in numbers at same spot last 20 years, RF11 At the present time I believe they are on the decrease, I have been catching Murray crayfish for over thirty years and the big hauls of legal sized crayfish are a thing of the past, RF12 No way, I don t think it is sustainable. People aren t catching nearly as many as they used to and it s only getting worse. The crays are all getting fished out. People, especially the youngens don t pay attention to the fishing regulations, RF15 No it s not sustainable. I ve seen a gradual decrease over the last 15 years in crayfish numbers and where they re caught. 15 years ago you used to be able to catch good crayfish, lots of them and big sizes, big males and females. It s all changed now, RF17 They get fished out too much. kids won t be able to see a cray in 20 years, RF20 There were big crays around 20 years ago. You could see their white claws underneath the water and near the banks. Big ones too. They haven t been around for the last 15 years or so though, RF25 Abundance and distribution decreased in last 10 to 20 years, RF27 Us old blokes that used to go Murray crayfishing don t go as much cause it s been fished out too much ). 95

118 Thirteen percent of fishers interviewed regarded the Murray crayfish fishery as being sustainable. However, none of the fishers who said the fishery was sustainable provided a comment to as to why they thought it was sustainable Fishing regulations Eighty-seven percent of fishers commented that they perceived fishing regulations to be in place in order to ensure the sustainability of the species (RF1 [Regulations are in place] to try and stop people from wiping out Murray crayfish populations, RF2 They re [fishing regulations] in place to try and protect the future of the crayfish, RF4 [Regulations are in place] to try and allow the cray population to survive, RF25 Regulations are there to make sure the crays are sustainable ). The majority (90%) of fishers interviewed suggested that current fishing regulations for Murray crayfish in NSW should be changed (RF10 Yes [fishing regulations] should be changed to further protect the Murray crayfish, RF11 Regulations need to be changed otherwise there won t be any left for our kids to see. I don t reckon my grandkids will ever actually get to see a Murray cray ). Suggested changes to regulations included lower net and bag limits (RF2 Now you can only have five nets a person but that s still heaps. And people can still take five crays home each. With all the people crayfishing now, they re won t be any crays left soon, RF10 Bag limit reduced to 3 crays, that s still enough for a taste if that s why you fish for them ), shorter and different opening seasons (RF2 They need to minimise the duration of the open season, the numbers of crays are really dwindling under the current rules, RF3 Make the season when the females aren t in berry, don t know but feels kinda bad to be catching and handling all these berried females, RF12 The season needs to be started later to allow the females to breed undisturbed and to let the juveniles leave the mothers or at least let the eggs at least hatch before it is opened, RF25 Reduce open season to 3 months June, July and August ), more closed areas (RF2 Need more closed areas. But can t fix the problem by just reducing access to the river, cause then people need to go through private properties. Need to leave river access open for camping etc but close off areas to crayfishing, RF10 Introduce protected areas of the river where no recreational fishing is permitted, similar to a marine park, and in these areas undergo extensive surveying and population studies ) and no ban on the taking of berried females (RF30 Regulations need to be adjusted to limit the 96

119 impact on sex and size ratios. Allow take of berried females otherwise just more bigger females and less big boys; this can t be sustainable ). Changes to the fishing regulations for Murray crayfish, as suggested by recreational fishers in NSW, have been summarized in Table 18. Fishers also commented that the rules for fishing for Murray crayfish needed to be simplified (RF15 I used to fish often, every couple of weeks; now don t go out as much as there s nothing around left to catch and the complicated regulations make it too hard. Maybe go once a year. People don t cray anymore here; no crays, been fished out and rules making it too hard for them; can t be bothered; need simpler rules, RF24 Need simpler rules, so maybe like the red cross has simplified the life saving technique to just two breaths and 30 pumps, to make it easier to understand, remember and follow, regulations also need to be simpler ). Table 18. Summary of suggested changes to current fishing regulations for Murray crayfish in NSW as stated by the interview participants and the percentage of interviewers who suggested the change (fisher n = 30). Current fishing regulations Suggested changes to fishing regulations Size limit (OCL) Min 90 mm Max 120 mm Increase min. size limit (46%) Change max. size limit so all >13cm returned to water (20%) Bag limit 5 / person Decrease bag limit (56%) Net limit 5 / person Decrease net limit (36%) Decrease net limit per campsite (63%) Closed season (May-Aug) Shorter open season (June-Aug) (56%) Open season every second year only (13%) Closed areas Complete closure in NSW for 3-5 years (77%) No take on berried females No ban on berried female take (6%) 97

120 3.3.5 Compliance rates Perceived compliance Fishers perceptions of compliance rates with Murray crayfish fishing regulations in NSW were based upon observations of people fishing for crayfish and on conversations they had had with other fishers. Fishers perceived that compliance rates ranged from 10% to 90%, with an average non compliance rate perceived to be 43% (±5.5% SE). The three main fishing regulations that fishers commented on as not being complied with were size limits, bag limits, and no take on berried females, with 70%, 63% and 57% of fishers suggesting non compliance for each of these regulations, respectively (RF3 Don t even get any larger males anymore, all that s left is the large females that you can t take anyway. That s why so many people just wipe the eggs off by pulling the berried females through the water while the boat s going fast. That way you can t tell they ve taken the eggs off, RF12 Too many people are taking the young ones and the berried females, taking the eggs off them and keeping them. They don t care; they want to take as many as they can and at least the bag limit, but normally way over the bag limit ). Fishers commented that the low perceived compliance rates were generally the result of a lack of enforcement, a lack of individuals knowledge about fishing regulations and the perception that fishing regulations were not legitimate. The suggestions by fishers that there was a lack of enforcement of fishing regulations were mainly attributed towards low perceived numbers of fisheries officers patrolling rivers (RF2 But even if you do put in new regulations, it can t be enforced with the current enforcement strategy and lack of fisheries officers, RF3 Doesn t seem to be sustainable. Numbers seem to be decreasing each year. The rules might work in theory but they re not being enforced so they re not working in practice ); and due to the perception that individuals were taking whatever they liked and not caring about or following the regulations because they thought they would not get caught (RF2 There are some people that do the right thing, but there are heaps that don t. It s just too easy to break the rules at the moment. And everyone s got the attitude of well if I don t take them, someone else will, RF17 [Compliance with regulations is] low, I reckon it s about 30%. People just don t care, they take everything they catch if they don t think they ll get caught, RF18 Lots of people also just don t care, they keep 98

121 anything they can get their hands on, small ones, berried females, the lot. The crays that are too small to eat, they use as bait or churn them up to use as stew. We see heaps of people doing the wrong thing ). The comments relating to a lack of knowledge about fishing regulations was generally attributed to insufficient easily accessible information about them (RF2 Most people don t even know about the current crayfish regulations so it would be hard to tell everyone about changing regulations and enforce this, RF29 Need some signage to say what the fishing regulations are down here. No-one we ve spoken to has been able to find any information about the fishing regulations. It s really hard to find out. It s all word of mouth as to what the fishing regulations are ). Fishers comments related to illegitimate fishing authorities and regulations they implement were mainly associated with a perceived lack of scientific information backing fishing regulations (RF2 They ve [fishers] got the information required to make the rules, not the scientists who come out and do a one off snap shot survey and definitely not the policy makers who sit in their air-conditioned office and have got no idea what is really happening out here, RF4 Well if they re [fishing regulations] not based on fishers comments, they should be. The rules should be made up from the knowledge gained from fishermen that are out here fishing and seeing what s going on in the river, not the politicians or inspectors. The fishermen are the guys who know what s going on in the river right now; they should be asked what the rules should be. Like what you re doing now, but it should be done on a larger level and for all rules. There should be more people like you coming out and talking to the fishers, RF5 Fishers comments should be included, not the politicians who sit in their offices and do the bookwork, and the fishing inspectors don t even talk to fishermen anymore, they just come, issue the ticket and piss off, RF18 Regulations are made up by politicians sitting at their desk, who ve probably never even seen a Murray cray, have got no idea at what condition they are in and do not have any scientific backing to implement their regulations, RF26 [Regulations are] decided by people sitting in a desk who have no idea about the biology of crays. It s no wonder no one follows the regulations, when no one trusts that they are based on any real information. I don t reckon they [fishing regulations] or the people who make them are legitimate ). 99

122 Fishers over the age of 51 generally suggested that the younger blokes were responsible for most of the non compliance with fishing regulations (RF12 Compliance is less than 10%. People are not doing the right thing. Large groups of young people come down at night or for the weekend, drink a lot and go crayfishing, catching heaps at night and keeping everything and anything they can. They want a feed and have made a sport out of it; they try to outdo their mates and see how many they can get. They ruin it for everyone else. Need a better education campaign. Only need one from the group to say not to take them, RF23 Wouldn t take any young ones and stuck to our limit, the fisheries guys would always come around on the long weekend so you wouldn t risk it. We d get about 90 decent sized ones in a weekend. Everyone got a good feed. But we didn t take more than our limit. Not like the younger blokes; would see them with the whole front of their boat full of small crays; by the time the fisheries caught them, the crays were all cooked. No point taking the small ones, not much meat on them and need to let them grow so you get biggens the following year ). Fishers commented that, in particular, it was the individuals who went fishing with a lot of people at one campsite who were not following regulations (RF22 There s too many dickheads that just go and hammer one spot in a weekend and fish em all out, RF25 Once a year crayers are crap; they take everything from one spot, don t follow regulations; they re the ones that fisheries need to focus on ). Two fishers also suggested that they had observed fishing clubs not complying with fishing regulations (RF2 Actually we saw a fishing club out a few months ago, they were putting out heaps of illegal lines and hoop nets. We told them that we d cut the lines and that we d called the cops and they got out of there ) Personal compliance Fishers comments on their own compliance with fishing regulations varied from always following all fishing regulations to not following the majority of them. Fifty-three percent of fishers interviewed said that they did not always comply with fishing regulations. Of these fishers, all commented on at least two fishing regulations that they did not always comply with (RF1 Many people do not follow the regulations. Even I normally will start 100

123 craying a couple of days before the crayfish season opens and sometimes take more than one larger male per day ). The fishing regulations that fishers stated they did not comply with are listed in Table 19. Fishers generally said that they personally did not follow fishing regulations as it was easy to get away with it, that there weren t enough legally sized crayfish to catch so they caught and retained undersized crayfish and/or berried females, and that there were so few larger males around that they would keep more than one over the MLL if they caught it (RF3 It s just too easy to not follow them [fishing regulations]. I take more than one big male if we ever catch them. And since there s not many of the big fellas around, if we re wanting a decent feed just take the eggs off the females and keep the bigger females, RF6 It doesn t matter cause no-one complies with them [fishing regulations] anyway. You just get the crays at night and you can get as many as you like. We went out crayfishing during the day and caught nothing and then went out at night from 6 pm to 9 pm and caught 30 big crays plus some smaller ones. We kept them; there was no-one patrolling during the night. There were heaps of berried females, probably 9 out of 10 of the big females had eggs. We just ate the eggs like caviar and kept the females. More big females than males, probably half females, half males but the bigger ones were almost always the females. We kept the smaller ones and made a broth out of them which was excellent ). Table 19. Summary of fishing regulations not complied with as listed by recreational fishers in NSW (fisher n = 30). Fishing regulations Minimum size limit (90 mm OCL) Maximum size limit (1 > 120 mm OCL) Bag limit (5 / person) Closed season (May August) No take on berried females No mutilation Non compliance by recreational fishers Keep undersized crayfish Take more than one male > 120 mm OCL Keep more than 5 per person Start few days before closed season Fish in closed season Take berried females Remove claws and keep them 101

124 3.3.6 Future management In order for the sustainability of the Murray crayfish fishery to be improved, fishers commented that some changes to fisheries management were required. The main suggested changes included a total ban on fishing for Murray crayfish in NSW for three to five years, an increase in the number of fisheries inspectors patrolling the rivers, an increase in community education, an increase in communication between fishers, inspectors, managers and scientists, and an increase in the use of information from fishers in management. A minority of fishers also suggested introducing a ban on the use of fish finders, the implementation of aquaculture stock releases to rivers and the encouragement of a catch and release fishery. The main suggested change, with 77% of fishers interviewed suggesting it, was to implement a total ban on fishing for Murray crayfish in NSW for up to five years to allow population numbers to increase and assist in the compliance of regulations (RF2 Yeah the current fishing regulations do need to be changed. They need to put a total ban on crayfishing for three to five years. Let the populations and sizes get up and going again. We re only pulling up small crays now. Not even worth a feed on, RF4 Also the cray fishing needs to be banned for 3 years to allow the populations to recover. Most people throw back berried females but the young blokes are too stupid and don t throw them back. They don t realise that there won t be any around next year, RF11 Need to start off by closing it for five years and during that time work out how to implement regulations that will be either enforced or designed or managed in a way that people will comply with them, RF19 They need to close the crayfishing totally for at least five years. Just close it down, that s what I d like to see. They can t wait much longer to do something like close it down; it s going to be too late soon, might even be too late now ). The need to increase the number of fishing inspectors policing the rivers was suggested by fishers as a method to assist in the enforcement of fishing regulations and thus increase compliance rates (RF10 Increase the number of fisheries officers on the Murray during the winter months to enforce the current regulations, RF29 Need more monitoring from fisheries officers, as people are getting away with taking way over the limit and all the 102

125 berried females they are catching; need more surprise visits, spot checks to keep people on their toes ). The suggestion to increase community education was based on fishers wanting more, and more easily accessible, information about the biology of Murray crayfish, current fishing regulations, and the role of fishing regulations in the sustainability of the species (RF1 I tried to look up some information about Murray crays on the internet but there wasn t much information about them. Couldn t really find anything, RF2 I couldn t find anything on the internet about the regulations, RF10 I believe that a portion of the recreational fishers still take more than the current bag limit and also undersize or berried females. I think an awareness campaign is required to educate the public on the vulnerable nature of Murray crayfish, RF12 There s not information available about the biology of the crayfish and why it s important not to take so many and to stick to the regulations. This should also be put up on the signs. Need info on what [we] can and can t do and also about the seasons. People also couldn t plead ignorance then, RF27 Increased education, increased signage, increased biological information about crayfish to help people understand biology of them, and biology behind regulations, easier to find information. The oldens don t use internet, need more readily accessible information ). An increase in communication between fishers, fishing inspectors, managers and scientists was suggested, as fishers felt they had a large source of knowledge that was not being heard or utilised and that they did not get access to scientific information (RF2 Start interacting with the fishers who have the information more, to be able to make better rules, RF3 Spend more time out studying the crayfish or talking to local people, RF5 Most of the information from scientists is not passed on; they think the information is not for public to see and they get in their little groups and keep the info in their little groups. Doesn t do anything much good, RF15 There s not much information on cray biology, habitat etc; don t reckon much of this info is incorporated into the current regulations. Only way to find things out is to talk to the fishers, RF22 I could give you information records about all the crayfish we ve caught over the last 10 years, records of where, size, etc. but people don t want this cause it s just anecdotal evidence, not classed as real science so not useful. Anything that fishers or anyone that isn t a scientist and hasn t got a Md or PhD behind 103

126 their names says is just classed as anecdotal evidence. You need to be a scientist to get anything heard ). It was suggested that more information from fishers should be used and that fishers should get more of an opportunity to have their say in the management of the Murray crayfish fishery and in the setting of fishing regulations (RF4 Well if they re [fishing regulations] not based on fishers comments, they should be. The rules should be made up from the knowledge gained from fishermen that are out here fishing and seeing what s going on in the river, not the politicians or inspectors. The fishermen are the guys who know what s going on in the river right now; they should be asked what the rules should be. Like what you re doing now, but it should be done on a larger level and for all rules. There should be more people like you coming out and talking to the fishers, RF11 A survey should be set up, and when each person applies for their fishing licence they should also fill out a fishing survey. They should use this type of information when making the fishing regulations. The people out there crayfishing will probably know better what s going on than those making the rules. Use this and the other information available to make better rules that people will stick to. It s good to see someone doing surveys, need more surveys, need to engage crayfishers better, RF12 The oldies and us don t access the internet so we wouldn t even know how to start to make comments on those internet government websites to the rules. And we re the ones with the fishing experience ). The last three suggestions by fishers included introducing a ban on the use of technology such as fish finders that make catching larger numbers of crayfish easier (RF1 Now we might need stricter rules to deal with increased technology such as fish finders and depth meters that make it much easier to catch larger numbers of crayfish. Maybe people shouldn t be able to use fish finders and depth meters. Takes the sport out of the fishing and gives the crays less chance to build up populations, RF19 Too many people have their big boats, big motors, fish finders and all the other gadgets, the crays don t have a chance ); the implementation of aquaculture stock releases to rivers to assist in the buildup of Murray crayfish populations (RF1 A crayfish aquaculture should be done to put juveniles into areas like they do with cod and trout ); and the encouragement of turning the recreational fishing of Murray crayfish into a catch and release fishery (RF20 People should catch and 104

127 release them, there s not enough to keep now, RF21 More information about catch and release is needed ). 3.4 Discussion A high percentage of fishers in this research commented that they did not think that the current Murray crayfish fishery in NSW was sustainable because of their observed changes in abundance, population structure (size and sex ratios) and distribution of the species. Declines in Murray crayfish numbers over a ten to twenty year period were reported as one of the main reasons for the perception that current populations were not viable. Fishers noticed a change in the size and sex ratios, with greater numbers of larger females being captured compared to larger males and generally smaller crayfish being captured. Such local ecological knowledge (LEK) has previously been gathered and utilised around the world to provide baseline knowledge in a relatively reliable (Chapter 4 and Zukowski et al. (2011) provides detailed information on the reliability of fisher LEK), quick and economical way for common property resources such as fisheries (Silvano and Begossi 2005; Silvano et al. 2006; Silvano and Valbo-Jørgensen 2008; Valbo-Jorgensen and Poulsen 2000). Interviewees provided detailed information about the changes required to achieve a sustainable fishery for Murray crayfish. This information was provided freely even though it could potentially lead to changes in management resulting in fishing closures or the imposition of further restrictions on fishing regulations. In comparison, previous studies (Bergmann et al. 2004; Pederson and Hall-Arber 1999) indicated that few fisher respondents were willing to provide information that could result in management developments such as the implementation of further temporal closures that had potential to negatively impact on their ability to fish. In this present study, fishers suggested numerous changes to fishing regulations that could potentially result in increased fishing restrictions. These suggestions were: An increase in the minimum size limit to 11 cm OCL to allow a greater proportion of sexually mature females to come into berry before they could be caught. 105

128 A change in the maximum slot limit so all crayfish above 13 cm OCL were returned to the water to allow larger individuals the opportunity to breed. A decrease in the bag limit to reduce the total number of crayfish captured. A decrease in the number of nets that could be used per person, or an inclusion of a maximum number of nets to be used per campsite, to reduce taking a large number of crayfish from one area. A shorter opening season to allow females to breed undisturbed. Gorden (1954) and Harding and Fisher (1999) argued that resource users of a common property such as a fishery only made decisions and adhered to policies that would increase their own profit in the short-term. They suggested that resource users had no incentive to take a long-term view to preserve the resources from overexploitation (Gorden 1954; Harding and Fisher 1999). A small number of fishers in our study suggested similar opinions with comments such as RF1 Fishers are naturally greedy and would want regulations changed so they could take more bigger crays, so wouldn t ask them for their input into fishing regulations. Similarly, Ostrom and Hess (2007) commented on open access regimes in common properties that allowed everyone to use the resource such as that typical in a recreational fishery. They suggested that, in such cases, the incentive for resources users to invest in improvements or limit their use of the resource was generally diminished (Ostrom and Hess 2007). Ostrom (1990) defined common pool resources (CPRs) as a natural or human-made resource which can be used by everybody but is not owned by one singular person or party and in which one individuals use of the resource affects the use of another. Where the use of the resource is over-consumed or the users do not provide or replenish the resource, the population of the resource can be depleted or led to a level of collapse (for example, the collapse of Northwest Pacific salmon). Where managed properly by an institution such as a body of resource users or a government organisation or a mixture of such individuals, CPRs can work efficiently and be supported at a sustainable level (Ostrom 1990). Murray crayfish form part of a CPR as they are not privately owned but a resource that can be used by everybody and the use of this resource by one person affects the use by others. 106

129 Murray crayfish are managed at a state level by fisheries management agencies. The use of this CPR has faced challenges as declines in the numbers and distribution of Murray crayfish have occurred since the 1950s and this study shows that fishers also do not feel as they have an adequate say in the fishing regulations nor are they provided with enough information on the resource. Ostrom (1990) states that dilemmas in the management of CPRs such as a lack of information about the resource or costs to users from the enforcement and policing of fishing regulations must be overcome in order for the institution to succeed and the resource to be managed at a sustainable level (Ostrom 1990). The authors findings showed that institutions that tend to succeed in this manner generally organise their behaviour using the following basic principles (Ostrom 1990): Group boundaries are clearly defined. Rules governing the use of collective goods are well matched to local needs and conditions. Most individuals affected by these rules can participate in modifying the rules. The rights of community members to devise their own rules is respected by external authorities. A system for monitoring member's behavior exists; the community members themselves undertake this monitoring. A graduated system of sanctions is used. Community members have access to low-cost conflict resolution mechanisms. For CPRs that are parts of larger systems: appropriation, provision, monitoring, enforcement, conflict resolution, and governance activities are organized in multiple layers of nested enterprises. Contrary to the findings of these previous studies, in this study the main change suggested by fishers to help achieve a sustainable fishery for Murray crayfish in NSW was to close the fishery entirely for a three to five year period in NSW. This would mean that a total fishing closure would be put on the Murray crayfish fishery in NSW as opposed to closed 107

130 areas or no-take zones which are currently in place in some areas. This was suggested by the majority of fishers and was generally suggested numerous times by each fisher throughout each interview. Fishers commented that although a total closure would result in them not fishing for Murray crayfish for a duration of time, future generations including their children and grandchildren could enjoy seeing and catching Murray crayfish. Fishers also suggested that a total closure in NSW for three to five years was one of the main ways to ensure that compliance with fishing regulations would be increased. They suggested that closing the whole Murray crayfish fishery in NSW would set boundaries for the whole of the state and thus be much easier for people to get caught if they did do the wrong thing. This is supported by Ostrom (1990). They argued that in order to effectively manage communal resources, clearly defined boundaries were required (Ostrom 1990). Fishers also commented that by closing the fishery in NSW the attitude of many fishers such as RF6 If we don t take them, someone else will, would be reduced as the majority of people would comply with the closure. Previous studies have shown that even where potential economic gains can be achieved from illegal fishing, the level of compliance can remain high where there is a mutual trust (norm) or anticipation that other people will comply with regulations (Young 1979). Previous authors have also argued that the only way to achieve sustainable fishing is to put a total closure on areas to provide fish with an opportunity to reproduce and grow to maturity without disruption (Schiermeier 2002) or to be protected until a better scientific understanding of the fishing resources and the impacts of exploitation are understood (Ballantine 1997; Lauck et al. 1998). This has also been evidenced in historical fisheries including significant increases in fish stocks in both the North Sea during the second world war when fishing activities were halted and around Cyprus during the 1980s following the extension of the usual summer no fishing period (Schiermeier 2002). Such spatial protection has been reported to be especially well suited for reef species and other organisms that are mainly sedentary as adults (Bohnsack 1994; Hastings and Botsford 1999; Plan Development Team 1990). For example, in Chile a fishing closure imposed by the government, which was followed by co-management and fishing regulations, recovered populations of the exploited muricid gastropod (Concholepas concholepas) (Castilla and 108

131 Defeo 2001). However, fisheries management tools such as gear restrictions or effort controls (e.g. size limits, bag limits etc.) have often been favoured over the use of closed areas even though these methods have often been shown to be insufficient to sustain fisheries (Boehlert 1996; Bohnsack 1998; Bohnsack and Ault 1996; Coleman et al. 1999; Lauck et al. 1998; Ludwig et al. 1993). In this study, the majority of fishers had strong personal norms or personal ethical views on what was right or wrong for future management directions to ensure the sustainability of Murray crayfish. These views tended to outweigh any potential negative fishing impacts for fishers associated with the closure of the fishery for a number of years or the implementation of more stringent fishing regulations. Recreational fishing for Murray crayfish was not suggested by any interviewees to be a means to gain economic benefits or as a supporting an important food source as is the case with many other fisheries (Hannesson 1996; Maynou and Sarda 2001; Silvano and Begossi 2005). This factor may have contributed to the acceptability of introducing total closures or increased fishing regulations. However, as with previous studies (Nielsen and Mathiesen 2003), the main incentives for fishing behaviour tended to be the expectations of a decent catch and the fishing experience. Thus, if regulations were not in tune with fishing practices and patterns, such as the current inability to catch legally sized or large numbers of Murray crayfish, strong incentives could be created to reduce compliance behaviour. Fishers perceived that almost half of fishers (43%) complied with fishing regulations and, similarly, just under half the number of fishers interviewed (47%) stated that they personally complied with fishing regulations. In comparison, previous studies of inshore multispecies ground fish fisheries such as lobster and scallop in Rhode Island and Massachusetts, New England, found that 50 to 90 percent of fishers generally complied with fishing regulations (Bean 1990; Sutinen and Gauvin 1988; Sutinen et al. 1990). In Lake Victoria, Africa, the world s second largest freshwater body of water, compliance rates were recorded as being 81 percent (Eggert and Lokina 2008). In NSW, compliance rates of approximately 90 percent have been recorded for recreational fishers in both coastal waters and freshwaters (NSW RFFTEC 2005; RFSTEC 2010). However, these average compliance levels can have large discrepancies. For example, during the January 109

132 long weekend in 2009, NSW Department of Primary Industries (DPI) fisheries officers checked 25 fishers on the Lachlan River downstream of Forbes and found that 18 people (72%) had not complied with fishing regulations (DPI NSW 2009). The majority of fishers interviewed for this study stated that they had witnessed illegal activity amongst other fishers. Although fishers stated that they did not agree with the most of the illegal fishing that took place, and that it angered them to see it, little action took place by them to deter this type of activity. Some fishers stated that they did ring the fishing offence hotline to report illegal activities. A few others stated that they did say something to illegal fishers. But similar to the findings from other researchers (Nielsen and Mathiesen 2003), there was little evidence to suggest that non compliance would result in widespread social pressure from fellow fishers. As in the Danish fishery (Nielsen and Mathiesen 2003), the general attitude of the fishers was to keep to their own business and not interfere with that of others. In this study, fishers stated that the main reasons why fishing regulations were not complied with were a lack of enforcement of regulations, a lack of fishers knowledge about regulations, and a perception that the fishing authorities and the regulations the fishing authorities implemented were not legitimate due to insufficient information backing regulations. Fishers suggested that compliance rates could be increased through easier access to, and increased information and education about, the biological and scientific reasons behind the regulations. Similarly, previous authors have argued that if fishers are provided with increased information about the biological values of regulations and biological consequences associated with non compliance, fishers morality might be strengthened leading to increased compliance rates (Sutinen et al. 1990). Nielsen and Mathiesen (2003) found that the level of compliance by fishers was influenced by their perceptions of the efficiency and meaningfulness of regulations. These factors resembled the effects on the protection of stocks or confidence in biological recommendations (Nielsen and Mathiesen 2003). Thus, lower levels of compliance would result when fishers did not feel that there was enough supportive biological evidence to ensure regulations would successfully achieve the protective outcomes they aimed to 110

133 achieve or when they perceived the biological evidence was not comprehensive and legitimate. Fishers suggested that there needed to be an increase in communication between fishers and policy makers, and that fishers needed to feel that they could contribute more to the process of changing or setting fishing regulations to help improve the sustainability of Murray crayfish. Previous research has also identified that the inclusion of resource users in the decision making process of common property resources was conductive to successful and stable local common pool resource management (Ostrom 1990). In order to achieve this, fishers felt that an increased number of inspectors was needed not only to enforce the regulations, but also to talk to fishers about the regulations and both educate fishers about the regulations and in turn gain knowledge from the fishers. Fishers felt that through doing this, compliance would be increased as they would feel as if they had been given a voice and made to feel they were being listened to. The need to improve communications between scientists, managers and fishers has been widely addressed in previous literature and has been recognised by all parties involved (Baelde 2001; Mackinson 2001; Moore 2003; Taylor 1998). By ensuring that communication is opened, fishers from our interviews felt that the fishing regulations would be perceived as more legitimate, accepted more readily and would achieve higher compliance rates, thus leading to increased sustainability of Murray crayfish. Nielsen and Mathiesen (2003) made similar observations in the Denmark commercial fishery. They commented that a distance between fisher and decision maker impedes the perceived legitimacy of procedures and regulations. They also pointed out that the general displeasure by fishers of the fishing regulations was an indication of the lack of perceived legitimacy in the policy making system, a feeling from fishers of not being involved in the stock assessment or decision making process (Nielsen and Mathiesen 2003). Further, previous authors have suggested similar opinions (Tyler 1990; Winstanley 1992), with suggestions that the involvement of fishers both enhances the credibility of the science behind regulations and increases the support for regulations based on the science (Bergmann et al. 2004). This has been demonstrated in cases such as the Barents Sea fisheries where the positive influence of communication on legitimacy was demonstrated 111

134 (Honneland 1998; Honneland and Jorgensen 2002). Suggestions have been raised to managers that new ways should be found in which fishers can be engaged in the policy process and the us-and-them interaction be broken down between fishers and managers (Schiermeier 2002). For example, John Pope, an independent consultant and former chief scientist at the Lowestoft Laboratory in East Anglia, part of Britain s Centre for Environment, Fisheries and Aquaculture Science is quoted as saying that It is utterly important to get fishermen s legitimate interests involved (Schiermeier 2002). Further, Baker and Pierce (1997) argued that although fishery societal values are important in the management of fisheries, they are not often explicitly adapted. They suggested that, in order to be effective, policy making structures need to reflect societal values and include fisher engagement (Baker and Pierce 1997). 3.5 Conclusion For regulations to be effective, they need to be based on sound information, include values of stakeholders, be understood and supported by recreational fishers and backed up by a significant level of enforcement effort. However, it is a difficult job for policy makers to incorporate all these factors into a working balance. Managers need to consider the biology of the species, the available science, community perceptions and values, consequences of regulations at a species and community level as well as at a social, economical and political level, the social acceptance of regulations and the associated compliance rates. In particular, the majority of fishers in our interviews regarded the sustainability of the Murray crayfish fishery as low based on their personal observations of declines in abundance and size of crayfish caught and changes in the sex ratios. They wanted sustainability to be increased so that future generations would be able to enjoy it, even if stricter regulations and temporary total closures were to be put on the fishery. Fishers wanted to see a number of changes to the future management of the Murray crayfish fishery in order for the sustainability of the species to be increased. These included a total ban on fishing for three to five years in NSW, an increase in compliance rates, an increase in community education, an increase in communication between fishers and management and scope for increased engagement of fishers into data collection and decision making procedures. 112

135 Chapter 4 Using fisher local ecological knowledge to improve management: the Murray crayfish in Australia Chapter 4 has been published as: Zukowski S, Curtis A, Watts R (2011) Using fisher local ecological knowledge to improve management: The Murray crayfish in Australia. Fisheries Research 110, Abstract The use of data provided by fishers is a contentious topic in fishery management. We compare fisher local ecological knowledge, fisher catch data and scientific data for Murray crayfish (Euastacus armatus) size and sex ratios in the River Murray, Australia, to determine if these data are consistent and if fisher knowledge can be a reliable input into fisheries management. Data were obtained through field surveys of crayfish populations, face-to-face fisher interviews and catch cards completed by fishers. All data sources indicated that there were higher numbers of crayfish < 90 mm OCL compared to 90 mm OCL and the sex ratio of larger crayfish ( 90 mm OCL) was skewed towards females. Fisher catch card and scientific survey data showed the size frequencies of male and female crayfish were significantly different. Study results suggest that fisher local ecological knowledge can be a reliable source of information to improve fisheries management. 113

136 4.1 Introduction Can recreational fishers provide a reliable source of knowledge for fisheries management? This question has long been debated between fishers, managers and scientists. Fishers often have a broad and detailed knowledge of fisheries stemming from ongoing and often extensive interactions with the environment in which they fish (Johannes 1981; Ruddle 1994) and through interactions with and observations of other fishers (Grant and Berkes 2007). They can provide species specific information on population dynamics and biological and ecological aspects such as spawning grounds, juvenile habitat, migration patterns and habitat preferences (Ames 2004; Hall-Arber and Pederson 1999; Maurstad and Sundet 1998; Neis et al. 1999) and about changes in stock and fishing pressure in response to regulatory changes (Neis and Felt 2001). Furthermore, if scientific data about the past status of fish stocks or environmental conditions are nonexistent, older fishers can be the only source of information available (Johannes 1998; Johannes et al. 2000). This type of knowledge is often referred to as local ecological knowledge (LEK), where a group of individuals hold a cumulative body of knowledge, often site-specific, about an ecological system. LEK is based on the interactions of individuals, humans and animals, with the environment and with each other. LEK can be gained through a mixture of observations and practical experience and can be adapted over time and handed down through generations (Berkes 1999). On a global scale there are many animal populations where there is insufficient scientific information to make sound management recommendations that will ensure sustainable populations (Gilchrist et al. 2005). The value of fisher LEK has been widely documented (Baticados 2004; Bergmann et al. 2004; Berkes and Folke 1998; Johannes 1998; Johannes et al. 2000; Maurstad 2002; Silvano and Begossi 2005) and there is increasing recognition that LEK can successfully complement scientific information to produce better management outputs (Chemilinsky 1991; Mackinson and Nottestad 1998). But, the inclusion of this knowledge into fisheries management remains the exception, rather than the rule. Alternative sources of information such as LEK need to be gathered, evaluated, and then tested through their application in management (Gilchrist et al. 2005). 114

137 Fisher LEK can be collected from fishers through a variety of methods including door-todoor, mail or telephone surveys, face-to-face interviews and logbooks and diaries which can occur at fishery access points (Pollock et al. 1994). LEK typically differs from scientifically generated data in that is it often qualitative and not quantitative (Mauro and Hardison 2000); relates to different time periods and locations; and involves different collection methods (Huntington et al. 2004a). There is a only a small numbers of peerreviewed articles drawing on LEK compared to the large number of scientific articles (Nadasdy 2003). Fishers often say that the value of their LEK is not recognised and challenge the scientific information that underpins fishery policy and management decisions (Delaney et al. 2007). On the other hand, scientists often mistrust the reliability of fisher LEK (Mackinson and Van der Kooij 2006). The term anecdotal knowledge is still widely applied to fisher knowledge and its translation into scientific knowledge and management remains limited (Neis et al. 1999; Palsson 1998). Thus, the reliability of LEK is often questioned and this type of knowledge is not readily accepted as an input to management. Unreliable data, be it scientific or local, can result in mismanagement of resources (Ludwig et al. 1993; Walters and Hilborn 1978). If fishery managers are to draw on fisher knowledge they need to be able to assess the reliability of LEK (Hamilton et al. 2005; Maynou and Sarda 2001; Neis et al. 2007). The comparison of LEK and scientific knowledge is one way of examining the reliability of both data sets, especially where the reliability of LEK is questioned. Comparing the independent outputs from these two methods can distinguish whether the two types of data corroborate (Rochet et al. 2008) or contradict (Degnbol 2003) one another. To the extent that both types of data are consistent, then confidence in both is enhanced (Huntington et al. 2004a). To ascertain the reliability of fisher LEK, previous authors have compared data collected by fishers with data collected by scientists (Baigòn et al. 2006; Bergmann et al. 2004; Bray and Schramm 2001; Ebbers 1987; Maurstad 2002; Maurstad and Sundet 1998; Silvano and Begossi 2002; Silvano et al. 2006; Silvano and Valbo-Jørgensen 2008). Ebbers (1987) compared data gathered using three methods, scientific electrofishing surveys, fishing tournaments, and fisher diaries, on the population structure of large-mouth 115

138 bass (Micropterus salmoides) in Minnesota. The study found much of the population data was similar between the three data sources and thus the authors concluded that large amounts of data could be reliably collected by volunteer fishers (Ebbers 1987). Similarly, in the Cabra Corral reservoir in Salta Province, northern Argentina, only small differences were found in the length of fish caught by fishers in tournaments, catamaran fishers and scientific gillnet captures (Baigòn et al. 2006). In Mississippi, Bray and Schramm (2001) found similarities in the length distribution of black bass Micropterus spp. (>250 mm) between angler reports and electrofishing samples (Bray and Schramm 2001). Bergmann et al. (2004) compared fisher surveys on the location of key habitat for gadoid fishes and whether the fishers had noticed features that might indicate the characteristics of essential fish habitat to that of standard ground fish surveys. The authors found that fisher information was not only broadly compatible with that gathered through scientific surveys, but fishers could also provide additional information (extra key fishing grounds/habitats) which was outside the scope of the scientific surveys (Bergmann et al. 2004). Similarly, Maurstad (2002) undertook interviews with fishers in Finnmark (Norway), to gain information about fished areas, species fished, gear used, people using the area, timing of fishing, and any changes in the fishery in the past few years. One of the outcomes of the study was a map (Maustad and Sundet 1998) in which fishers were able to identify 44 local spawning areas for cod whilst scientists knew of only four or five spawning areas (Maurstad and Sundet 1998). In this paper, we focus on the LEK of recreational fishers in a freshwater system. The majority of previous studies in this field have examined either commercial fisher LEK or marine systems or a combination of the two. In commercial fisheries, fishers are generally obliged to provide fishing and catch data to assist the monitoring of compliance with regulations, including quotas. These data are also used to monitor stock changes (Gerdeaux et al. 2006) and to facilitate the engagement of fishers in management and research. Until recently there has been little effort to gather data from recreational fishers to monitor the impact of fishing. Up to the 1970s it was generally perceived that commercial fisheries took the greater part of the total fishery catch and that recreational fishing did not make a large 116

139 impact (Ramsay 1991). It is now evident that the growth and impact of recreational fishing is greater than was previously anticipated (Ramsay 1991). Here, we discuss the findings of research that aimed to determine if freshwater recreational fisher LEK can be a reliable source of information for fisheries management. To do this, we tested two hypotheses (the catch is dominated by crayfish < 90 mm OCL (hypothesis one); and there is a skew in the sex ratios of larger crayfish ( 90 mm OCL) towards females (hypothesis two)), that explored whether fisher observations about the size and sex ratios of Murray crayfish (Euastacus armatus) in a recreationally fished section of the River Murray, NSW were consistent with data collected through fisher catch cards and scientific surveys. Murray crayfish are an iconic and highly valued recreational fishing species in the southern Murray-Darling Basin of Australia. The current status of Murray crayfish is largely unknown, however reports by fishers of declines in abundance, range and size have been reported since the 1950s (Horwitz 1990a; Horwitz 1995). In 2007, a review of the fishing regulations for Murray crayfish in NSW was recommended (Gilligan et al. 2007). This recommendation and the limited published biological and local information about Murray crayfish make them an appropriate species for such a study. To the extent that the three data sources were consistent, there would be support for the use of fisher LEK to inform fisheries management. 4.2 Methods Participant selection Participants for this study were indentified during field site visits. Recreational fishers who were fishing for Murray crayfish at river reserves and fishing locations within a 230 km reach of the River Murray between Hume Weir (36º S, 147º E) and Yarrawonga Weir (36º S, 145º E), NSW (Fig. 10) were approached during the 2009 open crayfish fishing season (May August). This river reach was used as it is a popular recreational crayfish fishing area. The sample of fisher informants was stratified to reflect the variation within the group (Seidman 1998) and achieve representation across the range of river access points, jurisdictions, week/weekends and days/nights (time of fishery effort) (Pollock et al. 1994). Thirty recreational fishers were 117

140 interviewed during 49 site visits and 30 separate fishers were issued with catch cards during an additional 42 site visits. During the 49 site visits undertaken for interview purposes, 14 site visits were conducted over a weekend, 35 during week days, 11 were conducted after dark and 38 were conducted during daylight hours. All fishers at each site were asked to be interviewed, and all accepted the invitation. During the 42 site visits undertaken to hand out catch cards 10 site visits were conducted over a weekend, 32 during week days, four were conducted after dark and 38 were conducted during daylight hours Fisher interviews Thirty interviews were undertaken to ascertain fisher knowledge of Murray crayfish population dynamics and associated fishing regulations. Semi-structured interviews (see explanation below) were used to facilitate a flexible approach that could explore viewpoints as raised by participants. This method enabled one-off interviews to be undertaken over a period of time and added depth and richness to the information obtained. The purpose of the research was described to all informants prior to interviews taking place. Consent for participation and tape recording was obtained before each interview. The duration of the interviews varied between 20 and 70 minutes. Where possible, interviews were taped and transcribed. Where informants preferred not to be recorded, extensive notes were taken during or immediately after the interview following the framework developed by Spradley (1980). An interview schedule was designed on the basis of six key questions (Table 20), as identified from issues prevalent in the research literature. The interviews were undertaken in a general conversation manner between the interviewer and informant. The interviewer attempted to gently guide the conversation rather than lead it and to incorporate the key questions, and where necessary, use probes (Table 20) to verify interpretations of responses provided by interviewees (Brittan 1995; Kvale 1996). 118

141 Table 20. Summary of the fisher interview schedule Key points for fisher interview schedule Fisher values Biological knowledge about Murray crayfish Sustainability of crayfish fishery Knowledge and views on fishing regulations Perceived compliance rates Future management of crayfish fishery Fisher catch cards Probes Why do you fish? What do you like about fishing? Views on fishing for future generations? Preferences for fishing? Where and how often do you fish? Where found? Habitat and environmental preferences? Growth rates? Is fishery sustainable? Why yes/no? How can it become sustainable? What are current regulations? History of regulations? Views on current regulations? Current compliance rates? Changes in compliance rates? Role of different stakeholders in management? Changes required? If yes, then detail? Thirty single-trip catch cards were issued at 22 sites to gather data on the size and sex ratios of Murray crayfish caught by fishers. Catch cards were used in this instance as other methods of angler surveys were inappropriate and the catch cards were the best methods for this study. As fishers have the potential to introduce bias into the data, on-site contact methods were used to decrease response errors following the methods of Pollock et al. (1994). For example, catch cards were explained and handed to fishers just before they began their crayfish fishing trip. As biases can result from misidentification of key species or misreporting length measurements, catch cards had in-depth information on how to identify and measure Murray crayfish (Pollock et al. 1994). To further ensure fisher bias was limited and to validate the data, I observed catch rates and measuring procedures on four occasions from the boat and on two occasions from the bank. No difference was found in my recordings and those of the fisher catch data. Catch card data collection included the 119

142 size, sex and number of crayfish caught and the date, time and location of the single fishing trip. Consent for participation was obtained before each catch card was handed out. Following the completion of the fishing trip, catch cards were collected from fishers or fishers returned the catch cards via mail Crayfish surveys Scientific crayfish surveys were undertaken to obtain sex and size ratios for Murray crayfish. Crayfish surveys were carried out monthly from January 2009 to December 2009 in a 230 km fished reach of the River Murray between Hume Weir (36º S, 147º E) and Yarrawonga Weir (36º S, 145º E), NSW (Fig. 10). Three fished river sites (located near Albury, Howlong, and Corowa) with easy boat and river access were sampled on three consecutive days at 9:00 (one site per day) each month. The sampling order of the three sites was randomised each month. The standardised sampling protocol recommended by Gilligan et al. (2007) was slightly modified and implemented as follows: single hoop nets of 700 mm diameter with a mesh size of 13 mm were baited with ox liver. The catch was recorded as catch per net per hour in order to standardise effort, with each net relocated after each haul. On each sampling day at each site twenty nets were set and checked hourly for a total of three hours (60 hoop net hauls per site). Data recorded from each net set comprised date, position (latitude and longitude), flow, depth, distance from bank, time set, time retrieved, and habitat characteristics. The catch data recorded comprised number of crayfish, OCL (measured from the rear of the eye socket to the middle of the rear of the carapace) to the nearest 0.1 mm, sex, the maturity stage of adult females (stages 1 3) (Turvey and Merrick 1997e), and whether females were in berry. 120

143 Figure 10. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray between Hume Weir and Yarrawonga Weir in which fisher interviews, catch cards and scientific surveys were undertaken in Data analysis For fisher interviews, the audio recordings and notes were transcribed verbatim to a spreadsheet. The interview transcripts were entered into and analysed using the software package QSR NVIVO 8. All data were thoroughly examined, and themes associated with crayfish biology (i.e. growth, size, sex, habitat) (Holdich 2002) were identified and coded (King and Horrocks 2010). These data were thoroughly searched for all divergent views to form a rich description of different factors related to Murray crayfish biology. The main theme relating to Murray crayfish biology which emerged was Murray crayfish size and sex ratios. 121

144 To compare the data collected through fisher interviews, fisher catch cards and scientific surveys on the size and sex ratios of Murray crayfish, two hypotheses were tested following the methods of Rochet et al. (2008). Using this method, fisher knowledge was assumed to be accurate and then compared against data obtained through the scientific surveys and catch cards. To make this comparison, fisher statements were coded to provide the input data for two testable hypotheses (Table 21). The hypotheses tested were true to fishers statements and as such, alternative hypotheses were used (Rochet et al. 2008). A two sample Kolmogorov-Smirnoff test (KS-test) was used to test whether there was a significant difference in the OCL frequencies between adult male and female crayfish in the data obtained through the fisher catch cards and scientific surveys. A KS-test was also used to analyse whether there were significant differences in the OCL for each sex in data from the fisher catch cards and scientific surveys. In each instance, the KS-test was used to determine if the two datasets differed significantly as this test does not make an assumption about the distribution of the data (non-parametric and distribution free). Size structure analysis (length-frequency histograms) was developed to determine Murray crayfish size and sex ratios in the data from the fishers catch data and scientific surveys. Chi-squared analysis was used to ascertain whether there was a difference between adult Murray crayfish sex ratios. Chi-square test for the comparison of two proportions (from independent samples) was used to determine whether sex ratios differed between fisher catch card and scientific survey data distributions. A G-test for goodness-of-fit was used to compare between the numbers of individuals found below and above 90 mm OCL in both the scientific and catch card data. 122

145 4.3 Results Fisher interviews Of the fisher informants, 25 were male and five were female. The age of informants ranged from 25 to 65 years of age (mean 41 ± 7.1 S.E.). From the analysis of the interview data, the dominant theme relating to Murray crayfish population biology which emerged was the population size and sex ratios of Murray crayfish. This theme emerged from all interview topics including those related to values, biological knowledge, fishing regulations, perceived compliance rates, sustainability, and future management. Under this main theme, two main observations were recorded by fishers in relation to their current catches: The majority of their catch comprised undersized (< 90 mm OCL) crayfish; and there were more larger females (> 90 mm OCL) than larger males (> 90 mm OCL) caught under current fishing regulations (Table 21). These observations were rephrased as the catch is dominated by crayfish < 90 mm OCL (hypothesis one); and there is a skew in the sex ratios of larger crayfish ( 90 mm OCL) towards females (hypothesis two) and these new statements became the two hypotheses to be tested against fisher catch card data and scientific data (Table 21). Only one fisher commented that they had observed no difference in the abundance or sex ratios of males and female crayfish. 123

146 Table 21. Fishers statements and associated hypotheses tested on Murray crayfish size and sex ratios in the River Murray in Catch dominated by crayfish < 90 mm OCL We re only pulling up small crays under the limit now. Last year we got a whole heap of small crays but you never get the big males anymore. Used to catch heaps around here, big ones too. Now there s only the small ones left that you can t take and not much of them around either. Have only caught two large males in the last two years. It s not sustainable, the big guys are getting wiped out and there are too many little guys. The numbers of crays has dropped heaps over the last 20 years and now we can t even catch one decent legally sized one. There s not many of the big fella s around, need the bigger boys back in the river. I have been catching Murray crayfish for over thirty years and the big hauls of legal sized crayfish are a thing of the past. Last year all we got was heaps of small ones, many of the size were 7-8 cm in length. Legal sized males are hard to find as are legal females without eggs, very few large male crayfish caught. H₀ Fishers Statements Skew in sex ratio of larger crayfish ( 90 mm OCL) towards females All been fished out, now nothing but small males and large females. Twenty five years ago there were heaps of bigger crays, more bigger males, not as many big females as now. Twenty five years ago, we used to catch heaps of crayfish, day or night. There were a lot more large males and not so many large females, now there s many more large females than large males. There is definitely more larger females than males. Don t even get any larger males anymore, all that s left is the large females that you can t take anyway. Taking just the males could lead to problems. The number of large males has decreased and the large females increased. More big females than males, half females, half males when small, but the bigger ones almost always the females. The current fishing regulations are not working, they re not sustainable. There s only large females and young ones left so people are now taking them. There are now a lot more bigger females than males. That can t last in the long-term. These days we only catch small male crays and large berried females. Don t get any large males anymore. 124

147 4.3.2 Fisher catch cards Thirty fishers filled out individual catch cards (19 on site and 11 by mail returns). Of these, 23 were male fishers, seven were female fishers and the age of fishers ranged from 18 to 58 years of age (mean 34 ± 8.9 S.E.). Fisher catch cards reported a total of 198 Murray crayfish (115 females + 83 males) captured from May to August The OCL size frequencies of male and female crayfish were significantly different (KS-test, D = 0.21, P = 0.025) (Fig. 11). These differences stem from the significantly skewed male to female sex ratio (0.72:1) as revealed by chi-squared test of goodness-of-fit with Yates continuity correction (only two categories present), (X 2 = 4.85, d.f. = 1, P = 0.028) and the significantly greater proportion of females greater than 90 mm OCL compared to males (male to female sex ratio is 0.36:1) (X 2 = 9.88, d.f. = 1, P = 0.001) (Table 22). From the total number of individuals captured (198), 75% of individuals were found to be < 90 mm OCL (149 individuals). Significantly higher numbers of individuals < 90 mm OCL were caught compared to those 90 mm OCL (G-test, G = 51.80, d.f. = 1, P < ) Frequency Occipital carapace length (mm) Figure 11. OCL frequencies for male (grey bar) and female (black bar) Murray crayfish sampled by recreational fishers in 2009 in the River Murray, NSW (n = 198). 125

148 4.3.3 Scientific field surveys Totals of 421 crayfish (248 females males) were collected over 1,280 fishing hours from January 2009 to December The OCL size frequencies of males and females were significantly different (KS-test, D = 0.15, P = 0.022) (Fig. 12). These differences stem from the significantly skewed male to female sex ratio (0.70:1) as revealed by chi-squared test of goodness-of-fit with Yates continuity correction (only two categories present), (X 2 = 13.01, d.f. = 1, P = ) and the significantly greater proportion of females greater than 90 mm OCL compared to males (male to female sex ratio is 0.46:1) (X 2 = 7.35, d.f. = 1, P = 0.006), (Table 22). From the total number of individuals captured (421), 86% of individuals were found to be < 90 mm OCL (361 individuals). Significantly higher numbers of individuals < 90 mm OCL were caught compared to those 90 mm OCL (Gtest, G = , d.f. = 1, P < ) Frequency Occipital carapace length (mm) Figure 12. OCL size frequencies of male (grey bar) and female (black bar) Murray crayfish, from scientific field surveys in 2009 in the River Murray, NSW (n = 421). 126

149 4.3.4 Fisher catch cards vs. scientific surveys No significant difference was found between the OCL frequencies of either sex of crayfish recorded through fisher catch cards and scientific surveys (KS-test, males D = 0.17, P = 0.08, females D = 0.15, P = 0.057) (Table 22). No significant difference was found between sex ratios found through fisher or scientific surveys when all size classes were combined (X 2 = 0.17, d.f. = 1, P = 0.678) or in the crayfish size group 90 mm OCL (X 2 = 0.74, d.f. = 1, P = 0.391) (Chi-squared test for comparison of two proportions). Table 22. Sex ratios of Murray crayfish obtained from fisher catch card results and scientific survey undertaken in 2009 the River Murray, NSW. Sex ratio (OCL) M F Fisher catch cards Scientific surveys Fisher vs. scientific Ratio (M:F) M F Ratio (M:F) Difference P Value All size classes % mm % Fisher interviews vs. fisher catch cards and scientific surveys Fisher observations that the catch is dominated by crayfish < 90 mm OCL (hypothesis one) and that there is a skew in the sex ratios of larger crayfish ( 90 mm OCL) towards females (hypothesis two), were supported by both fisher catch card and scientific data (Table 23). A significantly greater proportion of females 90 mm OCL compared to males was found through fisher catch cards (X 2 = 9.88, d.f. = 1, P = 0.001) and scientific surveys (X 2 = 7.35, d.f. = 1, P = 0.006), thus supporting hypothesis one (Table 23). Hypothesis two was also supported with a significantly greater number of crayfish found with < 90 mm OCL as compared to with 90 mm OCL through fisher catch data (G-test, G = 51.80, d.f. = 1, P < ) and scientific data (G-test, G = , d.f. = 1, P < ) (Table 23). 127

150 Table 23. Hypotheses tested through scientific and fisher catch card data on Murray crayfish size and sex ratios in the River Murray in H₀ supported by data H₀ Scientific Data Fisher Catch Cards Catch dominated by crayfish < 90 mm OCL Skew in sex ratio of larger crayfish ( 90 mm OCL) towards females Supported P < Supported P = Supported P < Supported P = Discussion Our findings on fisher knowledge suggest that fishers recognised that the size structure of the population and the sex ratios were not as they would be naturally or as they had observed them to be in the past. Fishers suggested a skew in the sex ratios of larger crayfish ( 90 mm OCL) towards females from the normally expected 1:1 ratio (e.g. More big females than males, half females, half males when small, but the bigger ones almost always the females, All been fished out, now nothing but small males and large females. ) Previous studies have demonstrated that crayfish populations generally have an approximately even sex ratio. For example, Astacus astacus was found to have male to female sex ratios of 1.04:1 and 1:1 in Lake Gailintas (Lithuania) (Mackeviciene et al. 1999) and in Lake Bronnen, Bavaria (Keller 1999), respectively. Male to female 1:1 sex ratios were also found in Swiss populations of Astacus leptodactylus (Stucki 1999) and in two native Mexican species, Procambarus diguetti and P. bouvieri, ratios were 1.04:1 and 0.99:1, respectively (Gutierrez-Yurrita and Latournerie-Cervera 1999). In VIC river reaches where closures (1 7 years) to fishing had been introduced, the average sex ratios of Murray crayfish was 1:1 (49% females) in the Ovens River, 1:1.3 (56% females) at Lake Nagambie and 1:1.2 (55% females) at Wodonga Creek (Barker 1992; Morison 1988). Similarly, in Tasmania, a 1:1 sex ratio for an non-fished population of Tasmanian giant freshwater crayfish (Astacopsis gouldi) was recorded (Horwitz 1991). Fishers also reported a tendency to now catch mainly undersized (< 90 mm OCL) animals (e.g. The numbers of crays has dropped heaps over the last 20 years and now we can t 128

151 even catch one decent legally sized one. ) Thus fishers observed that there was a difference between the current fished population dynamics and the population as it would be expected under natural non-fished conditions. They based their expectations of a natural population on what they had observed twenty to fifty years ago. The main purpose of this paper was to determine whether recreational fisher LEK was a potentially reliable form of knowledge. To do this, we tested two hypotheses based on these fisher observations to ascertain the reliability of fisher LEK for Murray crayfish size and sex ratios in a recreationally fished reach of the River Murray, NSW. Past literature has shown that comparing LEK to scientific data can generally result in three possible results (Huntington et al. 2004a; Silvano and Valbo-Jørgensen 2008). There could be significant differences between LEK and scientific data, the data between the two information sources may not be able to be compared, or a high comparability could be found between the two data sources confirming the reliability of the LEK (Silvano and Valbo-Jørgensen 2008). This study found no significant differences between the data obtained through fisher interviews and that obtained through fisher catch cards and scientific assessments. The two hypotheses tested based on fisher statements (the catch was dominated by crayfish < 90 mm OLC and there was a skew in the sex ratios of larger crayfish which are over the current minimum legal length (MLL) (90 mm OCL) towards females), were supported by both fisher catch cards and scientific data. There were also no significant differences found between fisher catch card data and scientific catch data on the sex and length distribution of Murray crayfish. Previous studies have found conflicting results, with some studies finding a higher number of discrepancies between fisher and scientific perceptions (Ainsworth and Pitcher 2005; Van Densen 2001) and other studies finding fewer differences between the two data sources (Baigòn et al. 2006; Bergmann et al. 2004; Bray and Schramm 2001; Ebbers 1987; Maurstad 2002; Maurstad and Sundet 1998). Conflicting results between fisher LEK and scientific studies do not however necessarily indicate a fault with either sources or a lack of reliability of fisher LEK. On the contrary, differences could provide two truthful but varied results. Such discrepancies between two sources of information can provide useful opportunities to investigate new biological data (Huntington et al. 2004a; Johannes 1981; 129

152 Johannes et al. 2000; Rochet et al. 2008). The differences between the data sources could be a result from the differences in methods, time periods, experience and spatial scale from which each data source is collected. For example, whilst fisher LEK can be based on longer term local observations, acquired and strengthened by being passed down through generations, scientific data collection methods tend to cover a broader spatial scale, be of a shorter time frame and use a more systematic approach (Huntington et al. 2004b; Poizat and Baran 1997). Fisher catch cards have been used in previous studies to obtain data including catch per unit effort (CPUE), catch composition, and location and year round timing of catches by recreational anglers around the world (Mann et al. 2002). Indeed, Rochet et al. (2008) found that on some occasions, such as when acquiring information on yields or lengths of driftnets, gathering fishers LEK was easier and faster than gathering scientific data. However, in recreational fishing, the data feedback loop is often poor or non-existent. Catch rates and fisher observations of changes in populations are generally not recorded in an ongoing and systematic approach to inshore recreational fisheries management. This is in spite of the evidence in commercial fisheries that these data can provide important information on ecosystem changes and can provide early detection of system changes. Recreational fishers are seldom required to provide fishing trip reports or catch rates and generally do not have an opportunity to provide their catch data and observations into the management of fisheries. Occasionally this occurs through voluntary surveys (Gerdeaux and Janjua 2009; Mann et al. 2002). Fisher LEK can provide long-term and up-to-date information (Rochet et al. 2008) and can often be the first to detect an environmental problem or change or suggest when regulations need to be introduced or changed (Alexander 2008). Here we propose an integrated management approach where changes in fisheries could be detected through fishers in the first instance and passed onto management. Fisher LEK could be used to improve fishery management by helping to identify ecosystem changes, which can then be scientifically monitored and assessed and the data fed back into management to help enable proactive and efficient decisions. For example, from our study, the high compatibility of the data from fisher interviews, fisher catch cards and scientific surveys suggests that fisher 130

153 information could be used as a reliable source of information to assist management. The changes in size and sex ratios in Murray crayfish as observed by fishers could be used as early indications which could guide specific scientific monitoring. Such monitoring could then be specifically tailored for management needs and would enable time and money savings and provide early indication to managers of changes in fisheries stocks or ecosystems and allow proactive management. This would be especially important in boomand-bust fisheries where a fishing resource could be depleted within a couple of years without proper management intervention (Boyer et al. 2001). 4.5 Conclusion The use of fisher knowledge in fisheries management has been long been debated, with scientists and managers concerned about the reliability of fisher LEK. This study tested the reliability of fisher LEK for Murray crayfish in the River Murray, Australia, by comparing data obtained through three different methods: fisher interviews, fisher catch cards and scientific surveys. The three data generating methods identified the same significant difference between the numbers of individuals found below 90 mm OCL and above 90 mm OCL; and significant skews in the size and sex ratios of larger crayfish towards females. The strong compatibility of the three data generating methods indicated that recreational fisher LEK could be a reliable data generating source which could detect population changes at an early stage and enable proactive and efficient management. 131

154 Chapter 5 Linking biology to fishing regulations: Australia s Murray crayfish (Euastacus armatus) Chapter 5 has been published as: Zukowski S, Watts R, Curtis A (2012) Linking biology to fishing regulations: Australia's Murray crayfish (Euastacus armatus). Ecological Management & Restoration 13, Abstract Murray crayfish (Euastacus armatus) can be legally fished by recreational fishers in two states of Australia. However there is limited published biological information on which recreational fishing regulations can be based. Murray crayfish populations were surveyed in a 230 km river reach of the River Murray, NSW, Australia. Only 39% of female Murray crayfish were sexually mature at the minimum legal length (90 mm OCL) set by current fishing regulations. Females first came into berry 16 days after the commencement of the open fishing season. During handling of berried females, an average of 1.3 eggs dropped off when the tail was left closed and 3.9 when the tail was opened. These results suggest that fishing regulations relating to minimum legal length and timing of the open fishing season may need to be re-evaluated. 132

155 5.1 Introduction Regulations have been used to manage fisheries around the world for hundreds of years (Huxley 1883). Determining fishing regulations to sustain a fishery is a difficult task. History has demonstrated that even small discrepancies between optimal and implemented fishing regulations can lead to population disturbances or even a population collapse (Finlayson and McCay 1998; Hannesson 1996). To maximize the chance of achieving a sustainable fishery, fishing regulations need to be based on current sound science, backed by fisher knowledge, implemented by expert management, and updated as new information becomes available (Winstanley 1992). However, time, financial, social, and political constraints mean that this is rarely possible. Establishing fishing regulations ideally requires specific biological information. Information on the size at onset of sexual maturity (SOM) and fecundity are key biological parameters needed to assess egg production and the applicability of size limits in fisheries management (Hobday and Ryan 1997). Knowledge of reproduction and recruitment timing is vital to enable the protection of species and instigate closed seasons and establish reserves or areas closed to fishing. Abundance data can provide confirmation that populations are at a healthy level and underpin rules about catch or bag limits (Attwood and Bennett 1995). Murray crayfish (Euastacus armatus) were once found throughout many of the rivers and tributaries of the Murray-Darling Basin, Australia (Fig. 13). This species was fished by Indigenous Australians, as evidenced by archaeological fossils identified along the River Murray in SA (Smith 1982). The world s second largest freshwater crayfish, it is slow maturing (6 9 years) and long lived (20 50 years) (ACT Government 1999; Geddes 1990). The number of eggs a female Murray crayfish produces is generally dependent on the size of the adult and can vary between 300 and 1,495 eggs (Johnson and Barlow 1982). Recruitment success in wild Murray crayfish populations has not been examined. Under captive conditions, mortality from egg to stage 3 juveniles and for post stage 3 juveniles to individuals 1.5 years of age was estimated to be 50% and 31 41%, respectively (Geddes et al. 1993). 133

156 Murray crayfish have suffered a decline in abundance and range since the 1950s (Horwitz 1990a; Horwitz 1995). Concern for the sustainability of the species was first raised through anecdotal reports by fishers who had noticed declining sizes and numbers of crayfish being caught (Horwitz 1990a). Suggested reasons for this decline include river regulation (McCarthy 2005; Walker 2001; Walker and Thoms 1993), pesticides and pollutants (Geddes 1990; O Connor 1986), habitat degradation (ACT Government 1999), and overfishing (Geddes 1990; Geddes et al. 1993; Horwitz 1990a; Lintermans and Rutzou 1991; McCarthy 2005). However, strong evidence for the cause of this decline is lacking as limited biological and ecological information has been published for this species. Commercial and recreational fishing of Murray crayfish peaked in the 20 th century. Commercial fishing was banned in 1990, and today Murray crayfish are fully protected in the state of SA and in the ACT. Murray crayfish can be legally taken by recreational fishers in NSW and VIC under prescribed fishing regulations. The five key recreational fishing regulations for Murray crayfish are a minimum legal length (MLL) (90 mm OCL), maximum slot limit where no more than one individual can exceed 120 mm OCL, restricted fishing season (open season May August), protection of berried females, and a bag limit (5). These regulations apply to both NSW and VIC (Department of Industry and Investment 2010; Department of Primary Industries 2009). In NSW, there is also a restriction of the fishery to waters outside listed trout waters; this represents a significant part of the Murray crayfish range (Department of Industry and Investment 2010). In a scoping study for Murray crayfish, Gilligan et al. (2007) rated the review of the appropriateness of current fishing regulations for Murray crayfish as a high priority. Here I examine biological parameters of Murray crayfish in a fished river section and discuss the implications of these results in relation to the current fishing regulations. Four biological parameters were investigated (year round catch rates, egg and hatchling timing, SOM and egg dislodgement rates) in a section of the River Murray, NSW. These parameters underpin three key fishing regulations for Murray crayfish: the MLL, restricted fishing season, and protection of berried females. 134

157 5.2 Methods Crayfish surveys Crayfish surveys were carried out monthly from January 2009 to December 2009 in a 230 km fished reach of the River Murray between Hume Weir (36º S, 147º E) and Yarrawonga Weir (36º S, 145º E), NSW (Fig. 13). Three fished river sites (located near Albury, Howlong, and Corowa) with easy boat and river access were sampled on three consecutive days at 9:00 (one site per day) each month. The sampling order of the three sites was randomised each month. The standardised sampling protocol recommended by Gilligan et al. (2007) was slightly modified and implemented as follows: single hoop nets of 700 mm diameter with a mesh size of 13 mm were baited with ox liver. The catch was recorded as catch per net per hour in order to standardise effort, with each net relocated after each haul. On each sampling day at each site twenty nets were set and checked hourly for a total of three hours (60 hoop net hauls per site). Data recorded from each net set comprised date, position (latitude and longitude), flow, depth, distance from bank, time set, time retrieved, and habitat characteristics. The catch data recorded comprised number of crayfish, OCL (measured from the rear of the eye socket to the middle of the rear of the carapace) to the nearest 0.1 mm, sex, the maturity stage of adult females (stages 1 3) (Turvey and Merrick 1997e), and whether females were in berry. 135

158 Figure 13. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the reach of the River Murray, NSW, in which crayfish surveys were undertaken Year round catch rates Year round catch rate data from total catches were recorded as individuals caught per net per hour (CPUE). CPUE was plotted against temperature and daily flow discharge. Temperature and daily flow discharge data were obtained with permission from the Murray-Darling Basin Authority (MDBA 2010). The CPUE of individuals 90 mm OCL (minimum legal length) was also plotted over time Egg and hatchling timing In addition to the monthly field sampling, crayfish surveys were undertaken daily in May and October to ensure early detection of the timing of onset of eggs and hatchlings. Ten 136

159 eggs or hatchlings were collected from each berried female and transported to the Murray Darling Freshwater Research Centre in Wodonga for staging under a Discovery V8 Zeiss Stereo microscope. A total of 75 samples of eggs (total 750 eggs) and 21 samples of hatchlings (total 210 hatchlings) were collected and examined Size at onset of sexual maturity (SOM) Monthly sampling data from January to December 2009 were used to determine SOM. Data from sexually mature females, as ascertained by the presence of eggs or ovigerose stage 3 setae (Turvey and Merrick 1997e), were collated and divided into 5-mm-OCL size classes. A size structure analysis (length-frequency histogram) was developed to ascertain female Murray crayfish maturity stages. Using the biological parameters as used by Hobday and Ryan (1997), the percentage of sexually mature females in a given size class (OCL) was determined, then fitted by means of a logistic equation: M = 100 / [1 + (L / L 50 ) b ], where M is the percentage of females in a size class, L is the OCL (mm), L 50 is the length at which 50% of females are mature (SOM), and b is a constant Percentage of sexually mature females in berry Data on sexually mature females with and without eggs from monthly surveys conducted between May and October 2009 were used to determine the percentage of sexually mature females carrying eggs over time Egg dislodgement rates Ten additional crayfish surveys were undertaken from May to August to determine rates of egg dislodgement. Crayfish were randomly sampled in the allocated river reach until 60 individual berried females were sampled. Crayfish were assigned to one of two treatments to investigate the effects of handling crayfish upon egg dislodgment. In treatment one, 30 crayfish were taken out of the hoop net and individually put straight into a container filled with water. For treatment two, 30 separate crayfish had their tails held open for two seconds, were checked for eggs and then individually put into a water-filled container. In both treatments, crayfish were returned to the river after 10 minutes and the container was 137

160 checked for eggs. The order of crayfish used for each treatment was randomly assigned. Each female was individually numbered using nail polish before being returned to the water. As females did not moult during the sampling period, nail polish was a sufficient marking technique to identify animals that were recaptured. Recaptured crayfish were subjected to treatment two (tail lift) but the data were only used to compare the number of eggs that became dislodged during the first and subsequent captures. Data from re-captured individuals were not used in the analysis for treatments one or two Data analysis Kruskal-Wallis tests were used to compare CPUE for total crayfish numbers and for individuals 90 mm OCL through the different months, the number of females and males captured between the different months, and the sizes of captured male and female Murray crayfish through the months. A G-test for goodness-of-fit was used to compare the number of sexually mature females caught per month and to compare the number of females with eggs or hatchlings captured between the months of May and October. For the egg dislodgement component of this study, a one sample Kolmogorov-Smirnoff test (KS-test) was initially used to test whether the data were normally distributed. As the data were not normally distributed, a two sample KS-test was used to analyse whether there were significant differences between the number of eggs that became dislodged from female crayfish during treatments one and two. A Wilcoxon matched-pairs signed-ranks test was used to determine whether there were significant differences between treatment two and repeat captures subjected to treatment two conditions as the data were not independent. 5.3 Results Year round catch rates A total of 695 Murray crayfish (412 females (53 berried), 283 males) were sampled from 1,982 fishing hours between January and December The highest rates of capture occurred from May to September ( individuals per net per hour), with 0.38 individuals per net per hour recorded in April and 0.2 individuals per net per hour recorded in all other months (Fig. 14). A significant difference was found in total CPUE through the different months (Kruskal-Wallis test, H = 17.28, d.f.= 1, P < ) (Fig. 14). 138

161 No significant difference was found in the number of females and males captured between the different months (Kruskal-Wallis test, H = 0.658, d.f. = 1, P = 0.417). There was a significant difference in the size of captured males and females through the months (Kruskal-Wallis test, H = , d.f. = 1, P < 0.002). A strong negative correlation was found between the number of individuals caught and water temperature (r 2 = -0.93) and the number of individuals caught and daily discharge (r 2 = -0.95) (Fig. 14). A positive correlation was observed between water temperature and daily discharge (r 2 = 0.93) (Fig. 14). Discharge (ML d -1 ) Open fishing season 1 May-31 August Temperature ( o C) CPUE (Ind h -1 ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 14. Total median Murray crayfish CPUE (Individuals per net per hour) (grey bars) from three sites in the River Murray, NSW (+/- Interquartile ranges) in 2009, plotted against water temperature ( o C) (black line) and daily discharge (ML day -1 ) (grey line) and timing of berries first present (black circle), larvae first present (grey triangle) and independent larvae (black triangle) (n = 421, net hrs = 1280). A total of 102 individuals 90 mm OCL were captured. A significant difference was found for individuals 90 mm OCL compared across the different months (Kruskal-Wallis test, H = , d.f. = 1, P < ) (Fig. 15). Sexually mature females with ovigerose 139

162 stage 3 setae were recorded in all months except from January to March when very low overall crayfish numbers were recorded. A significant difference was found in the number of sexually mature females captured between each month (G-test, G = 58.88, d.f. = 11, P < ) CPUE (Individuals hour -1 ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 15. Median CPUE of Murray crayfish 90 mm OCL (Individuals per net per hour) (grey bars) from three sites in the River Murray, NSW (+/- Interquartile ranges) in 2009 (n = 60, net hrs = 1280) Egg and hatchling timing During monthly sampling from May to November 2009 and daily sampling in May and October 2009, 87 sexually mature female Murray crayfish were sampled. The first berried females sampled were on 16 May. This date was 16 days after the opening of the crayfish fishing season when water temperature was 13 o C. Eggs first hatched into hatchlings on 9 October (146 days later) at a water temperature of 15 o C. None of the sexually mature females sampled on 13 November or at later sampling dates had attached hatchlings Size at onset of sexual maturity (SOM) In monthly sampling between April and September 2009, 248 female Murray crayfish ( mm OCL) were measured in total. Sexually mature females ranged between 78 and 140

163 124 mm OCL. No immature females were found 101 mm OCL. The mode of the lengthfrequency distribution peaked at 70 mm OCL (Fig. 16). Size classes between 70 and 90 mm OCL were well represented, whilst those 65 and 95 mm OCL had lower numbers of individuals. The percentage of sexually mature females increased between 85 and 110 mm OCL. A logistic model, fitted to the proportion of mature females in each 5 mm OCL size class, resulted in an estimated SOM of mm OCL (r 2 = 0.99; n = 15 size classes) (Fig. 16). At the MLL (90 mm OCL), 39% of female crayfish were sexually mature, and 98% were sexually mature at 110 mm OCL Percentage mature Frequency Occipital carapace length (mm) Figure 16. OCL frequencies (grey bars), SOM (size at onset of sexual maturity) per size class data (dots), fitted line (black line) and associated LC50 values (dashed line) for female Murray crayfish in the River Murray, NSW in 2009 (n = 248) Percentage of sexually mature females in berry During monthly sampling from May to October 2009, a total of 50 sexually mature female Murray crayfish were sampled. Of these, 29 (58%) were in berry and 21 (42%) were not in berry. No significant difference (G-test, G = 9.92, d.f. = 5, P = 0.078) was found between 141

164 the different months (May October, inclusive) in the numbers of sexually mature females with eggs or hatchlings (80, 75, 50, 61, 75, and 67%, respectively) Egg dislodgement rates A total of 71 berried female Murray crayfish were sampled (treatment 1 = 30, treatment 2 = 30, repeat captures = 11). A medium of 1.3 eggs per crayfish dropped off when no tail lift was performed (treatment 1), and 3.9 eggs per crayfish dropped off when the tail was lifted (treatment 2) (Table 24). A significant difference was found between the frequency distribution of the number of dislodged eggs between treatments one and two (KS-test, D = 0.45; P = 0.004). Eleven repeat captures were recorded with a medium of 3.6 dislodged eggs per crayfish. No significant difference was recorded between the number of dislodged eggs on the first capture subject to treatment two or repeat captures subjected to the same conditions as treatment two individuals (Wilcoxon matched-pairs signed-ranks test, W+ = 28, W- = 27, P = 1.000). Table 24. Number of Murray crayfish eggs dislodged under two treatments and under repeat captures (n = 71). Number of eggs dislodged Total Median Interquartile Max. Min. Treatment 1 (no tail lift) Treatment 2 (tail lift) Repeat captures (11) Discussion Minimum Legal Length (MLL) The MLL sets the smallest legal length at which a particular species can be retained if caught (Hill 1990). It is one of the most widely and historically used regulation tools in fisheries worldwide (Hill 1990). In Australia, the MLL was first introduced in 1873 into VIC to produce marketable sizes (Hill 1990). In the 20 th century, with a growing understanding of the limitations of fishing resources, the MLL is generally implemented to protect pre-spawning stock by allowing reproductive opportunities for females before they are recruited into the fishery (Annala et al. 1980) and to reduce fishing pressure (Hill 142

165 1990). The MLL for Murray crayfish in NSW was first set in 1989 at 80 mm OCL. Prior to this, fishers were able to catch and retain all sizes of crayfish. This limit has now been increased to 90 mm OCL (Department of Industry and Investment 2010). To assess the applicability of the MLL in fisheries management, the size at onset of sexual maturity (SOM) is often used (Hobday and Ryan 1997). Our logistic model showed that the size class in which 50% of female Murray crayfish were sexually mature was 91.8 mm OCL. Thus, under the current MLL, 50% of legally sized females must be able to survive throughout the fishing season and for at least one year under any fishing pressure to have an opportunity to breed. If management goals are to ensure at least 50% of females reach reproductive age before being legally targeted, the MLL would need to be set to at least 92 mm OCL in NSW. However, it is unknown how many or what percentage of females that have never bred can be taken before there is an effect on the sustainability of this fishery or the effects of other stressors. SOM in crayfish species can be affected by temporal (Annala et al. 1980; Bradstock 1950; Street 1969) and geographic (Hobday and Ryan 1997) variables as well as other factors such as population density, food availability, and growth rate (Annala et al. 1980). For example, temporal differences were found in the Murrumbidgee River, NSW with Murray crayfish found to have a SOM of 91 mm OCL in 1974 (Johnson and Barlow 1982) and 87 mm OCL in 1986 (O Connor 1986). Geographic variations were found by Hobday and Ryan (1997) in the SOM of the Southern rock lobster (Jasus edwardsii) in SA. Differences of up to 12 mm OCL were found between the SOM of females found in waters off southeastern SA and western SA (Hobday and Ryan 1997). SOM was also found to vary with temperature in local populations of J. edwardsii, with higher water temperatures resulting in faster growth and associated higher SOM estimates than lower water temperature environments (Annala et al. 1980; Bradstock 1950; Street 1969). For slow maturing species like Murray crayfish, even a small difference in the specified MLL could make a large contribution to local populations, especially in heavily fished areas. Hobday and Ryan (1997) suggested increasing the MLL in the Eastern Zone for (J. edwardsii), given the low percentage of mature females at the specified MLL. Currently, the same MLL for Murray crayfish is set for the whole of the state of NSW. As SOM is 143

166 influenced by many variables, management must be cautious to ensure populations from varied environments are protected by the MLL. Thus, it is vital that clear management goals are established when setting the MLL. This study also revealed that only 39% of females had reached sexual maturity at the current MLL for Murray crayfish. Hill (1990) argued that any increase in MLL would help increase the proportion of animals reaching reproductive size and thus did not necessarily have to be the size at which animals spawn. However he also stressed that the closer the limit was to spawning size, the more effective the regulatory tool became (Hill 1990). Gilligan et al. (2007) recommended that the appropriateness of current fishing regulations for Murray crayfish needed to be reviewed. One recommendation was to change the MLL to 100 mm OCL in NSW to ensure that almost 100% of females would have reached sexual maturity (Gilligan et al. 2007). Our current model showed that at 100 and 110 mm OCL, 88 and 98% of females were sexually mature, respectively. The findings from this study support the proposal to increase the MLL. However, the MLL needs to be tailored to specific management objectives relating to the appropriate percentage of sexually mature female crayfish required for a sustainable Murray crayfish fishery Restricted fishing season Restricted fishing seasons are implemented to protect fish during the spawning season and enable uninterrupted spawning, limit the magnitude of yearly catch rates and conserve heavily exploited species (McPhee 2008). For Murray crayfish, the open fishing season in NSW is from 1 May to 31 August each year. During March and April, Murray crayfish have soft exoskeletons (pers. obs.), and moulting generally takes place during late April to early May in the Murray and Murrumbidgee Rivers (Geddes et al. 1993; O Connor 1986). Therefore, opening the season during these months would mean crayfish do not have the protection of the hard outer shell and would be more susceptible to handling pressure. The open season for Murray crayfish coincides with the onset of the breeding season and when females are in berry. Female Murray crayfish first spawned in mid May when water temperature was decreasing (13 o C), and, as temperatures increased, eggs hatched (October) and hatchlings became independent juveniles (November). Similar results were found in the 144

167 Murrumbidgee River at Narrandera, where O Connor (1986) reported that mating took place in early to mid May at temperatures of o C, and by late May nearly all sexually mature females were in berry. Thus, under current fishing regulations, females that were not yet in berry could be legally taken at the commencement of the fishing season. If one of the aims of the restricted open season is to allow females to reproduce undisturbed, the open season should not commence until a significant proportion of all females have had an opportunity to mate and come into berry. Temperature is likely to be a stimulus for mating activity for Euastacus species. Similar temperature dependent cues for recruitment have also been reported for other Euastacus species including E. spinifer and E. bispinosus (Turvey 1980). O Connor (1986) found that E. armatus mated at temperatures between o C in the Murrumbidgee River, NSW and between 6 7 o C in Khancoban Pondage, NSW, and hypothesised that mating was likely cued by rapid declines in water temperature rather than specific temperature cues. In our study, numbers of Murray crayfish caught peaked in May to September, in parallel with lowest recorded water temperature and daily discharge, and were very low during other months of the year. Higher CPUE could thus be due to crayfish being more active during colder weather, lower water levels making catch easier, or a combination of these two parameters Protection of berried females Current fishing regulations require fishers to release berried female Murray crayfish. This regulation acts to protect berried females, eggs and hatchlings, limit fishing levels and help ensure population sustainability (McPhee 2008). Although berried females must legally be returned to the water, they can be caught, handled, and checked for eggs throughout the open fishing season. Horwitz (1990) suggested that although fishing regulations prevented the taking of adult berried female crayfish, the handling of berried females could result in damage and a decreased number of eggs and hatchlings reaching juvenile status. This study showed that handling berried female Murray crayfish resulted in eggs being dislodged on almost all occurrences. The number of eggs dislodged varied, and significantly more eggs were dislodged when the tail was opened to check for eggs than when the tail was left closed. Further, there was no significant difference found between the number of eggs 145

168 dislodged during the first and repeat captures of the same individuals, indicating that females would retain fewer eggs with repeated capturing and checking. During the months in which females were sexually active (May to November), 58% of sexually mature females captured were in berry. This, and the repeated captures, suggests that breeding female Murray crayfish are not trap shy and can be caught while in berry during the current open season. Similar findings have been reported in the Glenelg River, VIC, with over 95% of Glenelg spiny crayfish (Euastacus bispinosus) sexually mature females found to be in berry (Honan and Mitchell 1995c). Murray crayfish can generally carry between 300 and 1,495 eggs, depending on the size of the adult (Johnson and Barlow 1982). However, some individuals in this study carried considerably fewer eggs (< 50) (pers. obs.). Lower clutch weights and numbers of eggs have been shown to be correlated with smaller sized males in experiments conducted with J. edwardsii from temperate Australia and New Zealand, and Panulirus argus from the tropical western Atlantic (MacDiarmid and Butler 1999). In heavily fished areas, where one sex is exploited more than the other, the population sex ratio can be skewed towards one sex, especially in larger individuals. For example, male J. edwardsii account for 80% (Breen and Kendrick 1997) and male J. lalandii account for almost 100% (Pollock 1986) of the landed catch in certain areas of New Zealand and South Africa, respectively. Where large males are targeted through fishing and are rare, egg production can be limited through sperm-limited female fecundity (MacDiarmid and Butler 1999). In my study, only 15% (102 individuals) of the captured crayfish were found to be above 90 mm OCL. Thus, repeated captures and handling occurrences in a heavily fished area, especially where fishing pressure has diminished the number of larger males present, could potentially result in significant egg loss. Although the numbers of eggs dislodged in this study were low, a very non-aggressive form of handling pressure occurred; females were carefully placed into water filled containers and returned to the river after 10 minutes. More aggressive and prolonged practices could increase the risk of egg dislodgement. Further, the long-term effects of handling on egg retention and recruitment success are unknown. 146

169 5.5 Conclusion An ongoing challenge for fisheries managers is to establish fishing regulations that ensure healthy fish stocks for future generations. A review of fishing regulations for Murray crayfish was recommended as a high priority in NSW in 2007 (Gilligan et al. 2007). Here I set out to assess biological parameters of Murray crayfish in a fished river section to provide improved information to underpin fishing regulations. From a review of past literature and our research findings, two main management changes are suggested to enhance the Murray crayfish fishery. First, the MLL should be increased to allow a greater proportion of females to reproduce at least once. Second, the open season should be moved to a later date to allow the majority of females to come into berry prior to fishing activity. 147

170 Chapter 6 Recreational fishing effects on Murray crayfish (Euastacus armatus) population dynamics in Australian rivers Abstract The implementation of fishing regulations is a difficult task which becomes increasingly complex where the natural non-fished state of fish communities is unknown. Comparing fished and non-fished areas can provide detailed information about the effects of fishing pressure on biological dynamics, information that is vital for the management and protection of species. I assessed the effects of recreational fishing on the biology of Murray crayfish (Euastacus armatus) by comparing biological dynamics in fished (Blowering) and non-fished (Talbingo) reservoirs in the Murrumbidgee catchment, NSW. Hoop net surveys were used to obtain information on the catch per unit effort (CPUE), size and sex ratios, and size at onset of sexual maturity (SOM) of Murray crayfish. Differences were found in all examined biological dynamics between fished and non-fished sites. Talbingo Reservoir had a higher CPUE (0.22 individuals per net per hour), well represented size frequency distribution, approximately even male to female sex ratios above 90 mm OCL (0.96:1) and a SOM of 90.8 mm occipital carapace length (OCL). Blowering Reservoir had a low CPUE (0.02 individuals per net per hour), poor size frequency distribution and uneven sex ratios with skews towards females most evident in size classes 90 mm OCL (0.44:1). These differences suggest that recreational fishing can have a large impact on populations and that fishing regulations may need to be re-evaluated to ensure sustainable future populations of Murray crayfish. 148

171 6.1 Introduction The effects of fishing on the biological characteristics of marine and freshwater species are difficult to identify. The management of fishing regulations relies on knowledge of key characteristics such as abundance (Attwood and Bennett 1995), size and sex ratios (Barker 1992; Horwitz 1991), growth rates, reproduction, recruitment, fecundity (Rochet 1998), and size at onset of sexual maturity (SOM) (Gardner et al. 2006; Hobday and Ryan 1997; Rochet 1998). These factors can be influenced by environmental dynamics such as latitude (Gardner et al. 2006), geography (Annala et al. 1980; Hobday and Ryan 1997), time (Annala et al. 1980; Bradstock 1950; Street 1969), water temperature (Cox and Hinch 1997), and fishing pressure (Jennings and Kaiser 1998; Rochet 1998). The addition of fishing pressure to a non-fished system can lead to major changes in the structure of fish communities (Jennings and Kaiser 1998). In many marine and freshwater systems, the natural state of fish communities prior to the introduction of fishing is unknown. Thus, determining what management goals should be set to ensure sustainability in the system can be a difficult task, especially where no benchmarks have been set from a non-fished system. Comparing fished and non-fished areas can provide detailed information about the effects of fishing pressure on biological dynamics: information vital for the management and protection of species (Freeman 2008). Specifically, this type of information can provide comparisons between fished and non-fished populations on abundance, size and sex ratios, fecundity, SOM, growth rates, nutritional condition, and bacterial infections associated with handling. For example, Gardner (2006) examined the effects of density on growth and SOM in rock lobsters (Jasus edwardsii) by comparing non-fished marine protected areas and nearby fished areas on the east coast of Tasmania. Only a small change was found in SOM between the fished and non-fished areas despite large differences in lobster density between those areas. The researchers concluded that density was not a critical factor in the SOM of rock lobsters (Gardner et al. 2006). Platten et al. (2002) examined the effects of line fishing on the age of sex reversal of the venus tusk fish (Choerodon venustus) at numerous sites on the southern Great Barrier Reef. The authors found that fish in the highest mortality location underwent sexual reversal sooner than those in less fished areas 149

172 indicating that the venus tusk fish can alter its life cycle in response to fishing pressure (Platten et al. 2002). Locating suitable non-fished sites to use as benchmark comparison sites can often be difficult. Differences between habitats, temporal and geographical differences, and a lack of non-fished areas can hinder the establishment of suitable research sites. This is the case with the Murray crayfish (Euastacus armatus). This recreationally fished species was once found in the River Murray and its tributaries throughout the Murray-Darling Basin (Fig. 17), but has experienced declines in population abundance and distribution over the past 50 years (Horwitz 1990a; Horwitz 1995). Population declines have been related to river regulation (McCarthy 2005; Walker 2001; Walker and Thoms 1993), pesticides and pollutants (Geddes 1990; O Connor 1986), habitat degradation (ACT Government 1999) and over-fishing (Geddes 1990; Geddes et al. 1993; Horwitz 1990a; Lintermans and Rutzou 1991; McCarthy 2005). However, strong evidence for the cause of this decline is lacking as limited biological and ecological information has been published for this species. The comparison of fished and non-fished sites for Murray crayfish is difficult as most river reaches have been subjected to previous fishing pressure or are currently open to fishing. Further, the areas in NSW that have been closed to fishing generally consist of short river reaches. For example, on the River Murray fishing area closures include but, are not limited to, 50 metres upstream and 201 metres downstream of Yarrawonga Weir, 130 metres downstream of Hume Weir, and 400 metres upstream and downstream of Torrumbarry Weir (Department of Industry and Investment 2010). These reaches would not be appropriate to represent non-fished populations due to the strong possibility of a lack of independence from the fished areas. Even in reaches where fishing for Murray crayfish is currently closed, illegal fishing can and generally does take place (fisher pers. comm.). For example, Morey (1998) reported no significant differences in catch or growth rates of Murray crayfish between areas that were open and closed to fishing. The author concluded that these observed similarities were mainly due to illegal fishing taking place in the waters closed to fishing (Morey 1998). Other studies showed that very low catch rates of Murray crayfish were found at sites that were easily accessible to fishing such as picnic sites, roadsides and bridges (DSE 2003). 150

173 Hoop net fishing for Murray crayfish has been banned for over 20 years in Talbingo Reservoir. The use of lines to capture Murray crayfish was banned in However, anecdotal reports suggest that very few crayfish were captured in this manner in the reservoir when that was a legal method of fishing (fisher pers. comm.). Compliance with this ban appears to be very high: to date there have been no reports of illegal fishing in Talbingo Reservoir and people fishing in the reservoir for the past 20 years report no sightings of illegal fishing for Murray crayfish (fisher pers. comm.). Thus, to my knowledge, past and current Murray crayfish populations have not been exposed to fishing impacts in Talbingo Reservoir. In contrast to Talbingo Reservoir, Blowering Reservoir has been open to hoop net fishing in the past under prescribed fishing regulations for Murray crayfish that are consistent throughout NSW. Regulations include a minimum legal length (MLL) (90 mm OCL), maximum slot limit (where no more than one individual can exceed 120 mm OCL), restricted fishing season (open season May August), closed areas, protection of berried females, and a bag limit (5) (Department of Industry and Investment 2010). Fishers have reported that numbers of Murray crayfish in Blowering Reservoir had been high until approximately 2003, with captures of 100 crayfish in a weekend not uncommon from one area, and that a large range of size classes could be captured (fisher pers. comm.). Blowering Reservoir was closed to fishing for Murray crayfish for three years from 2004 to 2006 (inclusive) in response to anecdotal evidence from fishers suggesting that numbers of Murray crayfish had reduced significantly in the reservoir. Fishers reported that the decrease in Murray crayfish numbers in the reservoir was due to past heavy fishing pressure and possibly past low water levels in the reservoir (fisher pers. comm.). Fishing for Murray crayfish was re-opened in 2007 for one year but due to low numbers observed in the reservoir, a ban was put on the take of any Murray crayfish for a further five year period ( ). A re-assessment of the population status and the ban on fishing is set to occur in Here I aim to assess the effects of recreational fishing on the biology of Murray crayfish by comparing CPUE, size and sex ratios, and SOM from populations in a recreationally fished area (Blowering Reservoir) with a non-fished area (Talbingo Reservoir). 151

174 6.2 Methods Talbingo and Blowering reservoirs Talbingo (35º S, 148º E) and Blowering (35º S, 148º E) reservoirs occur within and adjacent to the Kosciuszko National Park just south of Tumut in the Murrumbidgee Valley on the Tumut River, NSW (Figs. 17 and 18). The reservoirs were constructed in 1968 and are used to supply water for irrigation and industry, hydropower and environmental flows and for flood mitigation (State Water Corporation 2009). The reservoirs are also used for recreational activities including waterskiing, sailing, boating, and fishing. They are stocked with fish including golden perch, rainbow and brook trout, and redfin (State Water Corporation 2009). Talbingo Reservoir has a surface area of 1,945 hectares (19.45 km 2 ), an average depth of 70 metres (maximum depth, 110 m), a capacity of 160,400 ML and an elevation of 549 m. It is fed by the Tumut and Yarrangobilly Rivers, and Long and Middle Ceeks. Blowering Reservoir has a surface area of 2,100 hectares (21 km 2 ), maximum depth of 91 m, a capacity of 1,628,000 ML, and an elevation of 376 m. It is fed by Tumut River and Sandy, Yellowin, Blowering and McGregors Creeks (State Water Corporation 2009). 152

175 Figure 17. Location of the likely natural distribution of Murray crayfish within Australia (Gilligan et al. 2007) and the location of the three River Murray sites and Blowering and Talbingo reservoirs in which crayfish surveys were undertaken. 153

176 Kosciusko National Park Kosciusko National Park Figure 18. Talbingo and Blowering reservoirs Crayfish surveys Crayfish surveys were carried out in Talbingo and Blowering reservoirs for two weeks annually in June 2008, 2009, and Seven randomly selected sites were sampled within each reservoir (14 sites in total) on each sampling trip on 14 consecutive days at 9:00 hrs each year. The standardised sampling protocol recommended by Gilligan et al. (2007) was slightly modified and implemented as follows: single hoop nets of 700 mm diameter with a mesh size of 13 mm were baited with ox liver. The catch was recorded as catch per net per hour in order to standardise effort, with each net relocated after each haul. On each sampling day at each site twenty nets were set and checked hourly for a total of three hours (60 hoop net hauls per site). Data recorded from each net set comprised date, position (latitude and longitude), time set and time retrieved. The catch data recorded comprised number of crayfish, OCL (measured from the rear of the eye socket to the middle of the rear of the carapace) to the nearest 0.1 mm, sex, the maturity stage of adult females (stages 1 3) (Turvey and Merrick 1997e), and whether females were in berry. Talbingo and Blowering reservoirs are similar in location, size and depth. However, the sampling was undertaken during drought conditions and low water levels were present in Blowering Reservoir during the sampling years. The reservoirs capacity is 1,628,000 ML, 154

177 and the volume of the reservoir dropped to approximately 650,000 ML during the sampling times. This may have also contributed to the low numbers of crayfish caught in the reservoir. Low catch rates in Blowering Reservoir made statistical comparisons between the two reservoirs not possible for all of the Murray crayfish biological dynamics examined. Where comparisons between the two reservoirs were not possible, Murray crayfish biological dynamics from the reservoirs were compared with a 230 km recreationally fished reach of the River Murray between Hume Dam (36º S, 147º E) and Yarrawonga Weir (36º S, 145º E), NSW as detailed in Chapter 4 (size and sex ratios) and Chapter 5 (SOM and CPUE). Athough comparisons between a reservoir and a river are not ideal as there are many differences between the two enrionments such as flow, water temperature, habitat and depth, the lack of available data on Murray crayfish populations in other fished reservoirs and the low numbers of Murray crayfish found in Blowering Reservoir made this comparison necessary in this instance Data analysis CPUE Catch rate data from total catches were recorded as individuals caught per net per hour (CPUE). Kruskal-Wallis tests were used to compare total CPUE and the number of females and males across the years in Blowering and Talbingo reservoirs. A Mann-Whitney U-test was used to compare total CPUE between the two reservoirs. A G-test for goodness-of-fit was used to compare the number of sexually mature females caught each year and to compare the number of females with eggs captured each year in each reservoir. The CPUE for combined three year data for males and females and combined males and females in Blowering and Talbingo reservoirs was plotted Size frequencies and sex ratios A two sample Kolmogorov-Smirnoff test (KS-test) was used to test whether there was a significant difference in the OCL size frequencies between years for each sex in Talbingo Reservoir to determine whether the three years of data could be pooled. The KS-test was used to determine if the two datasets differed significantly as this test does not make an assumption about the distribution of the data (non-parametric and distribution free). The 155

178 KS-test could not be used to determine whether there was a difference in the OCL size frequencies between years in Blowering Reservoir as there were insufficient numbers of individuals. A two sample KS-test was used to test whether there was a significant difference in the OCL size frequencies between male and female crayfish in Talbingo Reservoir. A KS-test could not be used for Blowering Reservoir as there were too few males captured in this reservoir. Statistical tests could not be performed to determine whether there were significant differences in the OCL size frequencies in each sex between Talbingo and Blowering reservoirs due to insufficient numbers of Murray crayfish captured in Blowering Reservoir. Size structure analysis (length-frequency histograms) was undertaken in Talbingo and Blowering reservoirs. Chi-squared analysis was used to ascertain whether there was a difference in adult Murray crayfish sex ratios in Talbingo Reservoir between years. A chi-square test for the comparison of two proportions (from independent samples) was used to determine whether sex ratios differed between Talbingo and Blowering reservoirs. A chi-square test for the comparison of two proportions (from independent samples) was used to determine whether sex ratios differed between Talbingo Reservoir and the River Murray and between Blowering Reservoir and the River Murray SOM Inadequate numbers of individuals were recorded for Blowering Reservoir; thus only individuals from Talbingo Reservoir were used in SOM calculations. Annual sampling data from Talbingo Reservoir surveys were used to determine SOM. Data from sexually mature females, as ascertained by the presence of eggs or ovigerose stage 3 setae (Turvey and Merrick 1997e), were grouped into 5-mm-OCL size classes. A size structure analysis (length-frequency histogram) was developed to ascertain female Murray crayfish maturity stages. Following the methods of Hobday and Ryan (1997), the percentage of sexually mature females in a given size class (OCL) was determined, and then fitted by means of the logistic equation: M = 100 / [1 + (L / L 50 ) b ], 156

179 where M is the percentage of females in a size class, L is the OCL (mm), L 50 is the length at which 50% of females are mature (SOM), and b is a constant. 6.3 Results CPUE Totals of 188 (95 females (13 berried), 93 males) and 19 (11 females (2 berried), 8 males) Murray crayfish were sampled from 866 and 921 fishing hours in annual sampling from 2008 to 2010 in Talbingo and Blowering reservoirs, respectively. No significant difference was found in total CPUE through the different years in Talbingo (Kruskal-Wallis test, H = 0.080, d.f.= 1, P = 0.772) or Blowering reservoir (Kruskal-Wallis test, H = 0.014, d.f.= 1, P = 0.904). No significant difference was found in the number of males and females captured through the different years in either Talbingo (Kruskal-Wallis test, H = 0.079, d.f. = 1, P = 0.778) or Blowering reservoirs (Kruskal-Wallis test, H = 0.039, d.f. = 1, P = ). Therefore, CPUE data for the three years for each sex in each reservoir were combined (Fig. 19). The total CPUE for Talbingo Reservoir was 0.22 individuals per net per hour (F = 0.110, M = individuals per net per hour) and 0.02 individuals per net per hour for Blowering Reservoir (F = 0.012, M = individuals per net per hour) (Fig. 19). A significantly higher total CPUE was found in Talbingo Reservoir compared to Blowering Reservoir (Mann-Whitney U-test, H = 2.4, d.f. = 1, P = ). Totals of 45 and 14 individuals 90 mm OCL were captured in Talbingo and Blowering reservoirs, respectively (Table 25). 157

180 0.25 CPUE (Individuals h -1 ) Female Male Total Figure 19. Female, male and total median Murray crayfish CPUE (Individuals per net per hour) (grey bars) from Talbingo (black bar) and Blowering (grey bar) reservoirs (+/- Interquartile ranges) in combined years (2008, 2009 and 2010) (n = 207, net hrs = 1787). Totals of 28 and 10 sexually mature female Murray crayfish with ovigerose stage 3 setae were recorded in Talbingo and Blowering reservoirs, respectively. No significant difference was found in the number of sexually mature female Murray crayfish captured between each year in either Talbingo (G-test, G = 0.24, d.f. = 2, P = 0.887) or Blowering (G-test, G = 0.194, d.f. = 2, P = 0.907) reservoirs. Totals of 13 and 2 berried female Murray crayfish were recorded in Talbingo and Blowering reservoirs, respectively. Thus, of the total number of sexually mature females caught, 46% were berried in Talbingo Reservoir and 20% were berried in Blowering Reservoir. No significant difference was found in the number of berried female Murray crayfish captured between each year in either Talbingo (G-test, G = 1.058, d.f. = 2, P = 0.589) or Blowering (G-test, G = 4.394, d.f. = 2, P = 0.111) reservoirs Size frequencies and sex ratios No differences were found in the OCL size frequencies between years for either males (KStest, D = 0.247, P = (2008 vs. 2009), D = 0.161, P = (2008 vs. 2010), D = 0.256, P = (2009 vs. 2010)) or females (KS-test, D = 0.186, P = (2008 vs. 158

181 2009), D = 0.300, P = (2008 vs. 2010), D = 0.119, P = (2009 vs. 2010)) in Talbingo Reservoir, so data from 2008, 2009 and 2010 were grouped for each sex (Fig. 20) Frequency Occipital carapace length (mm) Figure 20. OCL size frequencies of male (grey bar) (n = 93) and female (black bar) (n = 95) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Talbingo Reservoir (n = 188). No significant difference was found in the OCL size frequencies between males and females in Talbingo Reservoir for all size classes (KS-test, D = 0.158, P = 0.177), size classes 90 mm OCL (KS-test, D = 0.121, P = 0.994), or size classes < 90 mm OCL (KStest, D = 0.203, P = 0.091). A significant difference was found in the OCL size frequencies between total female and sexually mature females in Talbingo Reservoir (KS-test, D = 0.506, P < ) (Fig. 21). 159

182 Frequency Occipital carapace length (mm) Figure 21. OCL size frequencies of total female (black bar) (n = 95) and sexually mature females (grey bar) (n = 28) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Talbingo Reservoir (n = 95). In Blowering Reservoir, due to the low numbers of individuals captured, statistical analysis on the OCL size frequencies between males and females could not be tested. However, a histogram demonstrates the OCL size frequencies of data grouped from 2008, 2009, and 2010 for each sex (Fig. 22). 160

183 Frequency Occipital carapace length (mm) Figure 22. OCL size frequencies of male (grey bar) (n = 8) and female (black bar) (n = 11) Murray crayfish, from scientific field surveys in combined years (2008, 2009 and 2010) in Blowering Reservoir (n = 19). No significant skews were observed in the sex ratios in Talbingo Reservoir when all size classes were compared (0.98:1) (X 2 = 0.005, d.f. = 1, P = 0.942) or when size classes 90 mm OLC were compared (0.96:1) (X 2 < , d.f. = 1, P = 1.0) (as revealed by chisquared test of goodness-of-fit with Yates continuity correction (only two categories present) (Table 25). In Blowering Reservoir, male to female sex ratios of 0.73:1 and 0.44:1 were observed when all size classes were compared and when size classes 90 mm OLC were compared, respectively (Table 25). Statistical analyses could not be performed to determine if the observed skews in the sex ratios in all size groups and in those 90 mm OCL were significant in Blowering Reservoir due to low numbers of individuals. Significant differences were found in the sex ratios between Talbingo and Blowering reservoirs when all size classes were combined (X 2 = 20.51, d.f. = 1, P < ) and in size groups 90 mm OCL (X 2 = 17.49, d.f. = 1, P < ) (Chi-squared test for comparison of two proportions). 161

184 Table 25. Sex ratios of Murray crayfish in the River Murray, NSW in 2009, and in Blowering and Talbingo reservoirs from 2008 to Sex ratio (OCL) M F Talbingo Reservoir Blowering Reservoir River Murray Ratio (M:F) M F Ratio (M:F) M F Ratio (M:F) All size classes < 90 mm mm Significant differences were found in the sex ratios between Talbingo Reservoir and the River Murray data when all size classes were combined (X 2 = 59.01, d.f. = 1, P < ) and in the crayfish size group 90 mm OCL (X 2 = 27.04, d.f. = 1, P < ) (Chisquared test for comparison of two proportions) (Table 26). No significant differences were found in the sex ratios found between Blowering Reservoir and the River Murray when all size classes were combined (X 2 = , d.f. = 1, P = 0.981) or in those 90 mm OCL (X 2 = 0.027, d.f. = 1, P = 0.871) (Table 26). Table 26. Differences between the sex ratios of Murray crayfish in the River Murray, NSW in 2009, and in Blowering and Talbingo reservoirs from 2008 to Talbingo vs. Blowering Talbingo vs. River Murray Blowering vs. River Murray Sex ratio (OCL) Difference P Value Difference P value Difference P value All size classes 25% < % < % mm 52% < % < %

185 6.3.3 SOM In annual sampling between 2008 and 2010, 95 ( mm OCL) and 11 ( mm OCL) female Murray crayfish were measured in total in Talbingo and Blowering reservoirs, respectively. In Talbingo and Blowering reservoirs, sexually mature females ranged between 74 and 120 mm OCL (28 individuals) and 88 and 152 mm OCL (10 individuals), and no immature females were found 100 and 92 mm OCL, respectively. In Talbingo Reservoir, the mode of the length-frequency distribution of females peaked at mm OCL (Fig. 23). Size classes between 75 and 95 mm OCL were well represented, while those 70 and 100 mm OCL had lower numbers of individuals. The percentage of sexually mature females increased between 75 and 100 mm OCL. For Talbingo Reservoir, the logistic model, fitted to the proportion of mature females in each 5 mm OCL size class, resulted in an estimated SOM of mm OCL (r 2 = 0.96; n = 16 size classes) (Fig. 23). At the MLL (90 mm OCL), 49% of female crayfish were sexually mature and 80% were sexually mature at 120 mm OCL Percentage mature Frequency Occipital carapace length (mm) 0 Figure 23. OCL size frequencies (grey bars), SOM data (dots), fitted line (black line) and associated LC 50 values (dashed line) for female Murray crayfish in Talbingo Reservoir (n = 95). 163

186 6.4 Discussion CPUE The effects of fishing pressure on population dynamics such as crayfish abundance, size frequencies, sex ratios and SOM can be more accurately determined if there is information about what the natural state of populations should be under non-fished conditions. A large difference was found in crayfish abundance between Talbingo and Blowering reservoirs, with much higher rates of capture recorded in the non-fished Talbingo Reservoir and very low catch rates recorded in the fished Blowering Reservoir. Freeman (2008) used diver and pot surveys to assess the biological dynamics of rock lobsters (Jasus edwardsii) under fished and non-fished conditions within and surrounding two marine reserves on the east coast of the North Island of New Zealand. Similarly to my results, the author found a higher abundance of lobsters in non-fished areas (Freeman 2008). Gardner (2006) also found nonfished sites of the same species to have a higher density of lobsters than fished areas on the Tasmanian coast. Silvano et al. (2009) compared the abundance of 70 species of fish in lakes open and closed to fishing the Central Brazilian Amazon. The authors did not find any difference in the abundance of the 14 fish species that were intensely harvested between fished and non-fished lakes, however they did note that the abundance of a commercially harvested species was higher in non-fished lakes (Silvano et al. 2009). Decreases in abundance in a fish species can have impacts on the ecology of the ecosystem in which they habitat. Although no specific studies have examined the ecological roles of Murray crayfish in freshwater environments, the broad role of crayfish as leaf shredders, detritivores and invertebrate predators is better understood (Lewis 2001; Turvey and Merrick 1997a; Usio and Townsend 2004). For example, field experiments revealed that crayfish (Paranephrops zealandicus) reduced fine sediment and played an important role in regulating the local abundance of invertebrates (Usio and Townsend 2004). Crayfish were recorded to selectively prey on invertebrate species such as large Tanypodinae thus declining numbers of specific species, and appeared to contribute to increases in the numbers of some invertebrate species such as Deleatidium mayflies through the removal of their predators (Usio and Townsend 2004). Where crayfish are present at large densities their foraging behaviour could reduce the growth and numbers of aquatic plants and could 164

187 also result in fish eggs attached to a substrate being consumed and thereby decreasing successful recruitment of fish species (Dorn and Wojdak 2004). Crayfish are also known to be an important component in the diet of fish, birds, mammals and reptiles (Nyström 2001) and in hosting and thus supporting lower order organisms including a variety of mectosymbiotic and parasitic organisms, worms and other microcrustaceans. Although Blowering Reservoir has been closed to fishing for Murray crayfish since 2008, the year sampling first commenced no significant increase in Murray crayfish abundance was observed from 2008 to 2010 in this study. The review of previous studies of recovering stocks in closed areas showed that stock increases generally occur rapidly and often double or triple in two to five years (Gell and Roberts 2003). However for slow growing and late maturing species such as Murray crayfish, populations may take longer to recover. Further, the drought conditions resulting in low water levels in Blowering Reservoir during the time of sampling may have further contributed to low catch rates. This fishing closure is expected to remain until Future crayfish surveys in 2012 and beyond will be required to ascertain whether population numbers have increased and whether there has been successful recruitment of juveniles in this reservoir Size frequencies and sex ratios Size frequencies Data on size and sex ratios can provide important information for fishing regulations. These data can identify irregularities in population structure such as a skew in the sex ratios or limited recruitment (Adams et al. 2000; Barker 1992; Horwitz 1991). This information can reflect the extent of fishing pressure upon a population and inform the setting of regulations for size limits (Krouse 1973). The population structure in Talbingo Reservoir was well represented at all size classes captured. The capture of a large range of size classes, particularly juveniles and berried females, indicates that the Murray crayfish population in Talbingo Reservoir is reproducing and recruiting successfully. The results from Talbingo Reservoir were very different to those found in Blowering Reservoir. In the latter reservoir, the size distribution of the population was not well represented by different size classes. No juveniles or individuals less than 88 mm OCL 165

188 were captured, and only a small percentage of sexually mature females caught were in berry. Although catching juvenile Murray crayfish has been problematic in the past, with recorded captures being limited to dive surveys in the 1980s (O Connor 1986), their successful capture in Talbingo Reservoir may indicate that the inability to find them in Blowering Reservoir was not a technique issue. The lack of juveniles and berried females may be an indication that successful recruitment is not occurring in Blowering Reservoir. The size classes above 90 mm OCL were well represented in both males and females in Talbingo Reservoir, whereas in Blowering Reservoir and in the River Murray fished areas, numbers of crayfish in size classes above the current MLL (90 mm OCL) were reduced, especially for male crayfish which may be more susceptible to fishing pressure under current fishing regulations. This comparison between the fished and non-fished areas highlights the effects on size structures from fishing pressure. Similarly, Adams et al. (2000) compared reproductive dynamics including size frequencies, age structures of mature females and sex ratios of the coral trout (Plectropomus leopardus) between coral reefs that were open and closed to fishing of the Great Barrier Reef. The authors found that on reefs closed to fishing for eight to ten years, there were higher numbers of males greater than the MLL, and significantly older and larger females present, compared to reefs open to fishing (Adams et al. 2000). Freeman (2008) also found a higher proportion of lobsters over the MLL, higher female fecundity and faster growth rates for sublegal male lobsters in non-fished marine reserves as compared to surrounding fished areas. Similar population profiles have been noted in fished areas for other species. For example, Murray cod (Maccullochella peelii), an endemic and native species found throughout the Murray-Darling Basin, was found to have all year size classes well represented up to the MLL (50 cm in 2005) and above that size, numbers of individuals reduced dramatically or were nonexistent in some waters (Nicol et al. 2005). These changes in size structures were thought to be associated with fishing pressure on larger legally targeted individuals (Nicol et al. 2005). The effects of commercial fishing pressure on the natural American lobster (Homarus americanus) population was evident in length frequency data collected in coastal waters near Boothbay Harbor, Maine from 1968 through to 1970 (Krouse 1973). Similar to my findings from the River Murray, sharp decreases in the number of lobsters above the 166

189 MLL (81 mm OCL) were observed by Krouse (1973) which reflected the influence of commercial exploitation. The study found that lobsters above the legal size comprised only 6 to 9% of the catches from the three sampling years (Krouse 1973). In our River Murray data, only 15% (102 individuals) of the captured crayfish were found to be above the MLL (90 mm OCL) Sex ratios In Talbingo Reservoir, at all tested size classes for crayfish, males and females were found to have an approximate even sex ratio. Similar results were found for the American lobster (Homarus americanus) collected in coastal waters near Boothbay Harbor, Maine (Krouse 1973) and off Monhegan Island (Cooper 1970). In these studies, no significant differences were found between the number of immature male and female lobsters (Krouse 1973) or those with an average carapace length of 90 mm OCL (Cooper 1970). The authors suggested that these findings were the result of male and female lobsters having approximately even moulting frequencies and growth increments (Cooper 1970; Krouse 1973). Numerous other studies have also recorded approximately even sex ratios in crayfish populations. For example, populations of Astacus astacus were found to have male to female sex ratios of 1.04:1 in Lake Gailintas (Lithuania) (Mackeviciene et al. 1999), Swiss populations of Astacus leptodactylus were found to have ratios of 1:1 (Stucki 1999), and in two native Mexican species, Procambarus diguetti and P. bouvieri, the ratios were 1.04:1 and 0.99:1, respectively (Gutierrez-Yurrita and Latournerie-Cervera 1999). This pattern was also observed for Murray crayfish in VIC river reaches where fishing closures were in place. For example, the average sex ratios of Murray crayfish was 1:1 (49% females) in the Ovens River, 1:1.3 (56% females) at Lake Nagambie and 1:1.2 (55% females) at Wodonga Creek (Barker 1992; Morison 1988). Similarly, even sex ratios were recorded for the Tasmanian giant freshwater crayfish (Astacopsis gouldi) in non-fished river reaches in Tasmania (Horwitz 1991). In the two fished sampling areas, Blowering Reservoir and the River Murray, the sex ratios were similar to each other but different from those found in the non-fished Talbingo Reservoir. In the fished areas, sex ratios differed between males and females in all size 167

190 classes. They were skewed towards females in all size classes examined, and this skew was most extreme when examining size classes above the current MLL for Murray crayfish in NSW (90 mm OLC). Sex ratios have previously been reported to differ from a 1:1 ratio in parallel with fishing pressure and some fishing regulations. For example, in south-west VIC, Euastacus bispinosus had a reported male to female sex ratio of ( :1) in a fished area where there was a no take policy on berried females and a minimum size limit (Honan and Mitchell 1995c). Honan and Mitchell (1995) reported the domination by females of the larger size classes was likely to be a result of the larger males being targeted by fishers. In the Murrumbidgee River between 1974 and 1998 male to female sex ratios of between 1:1 and 1:1.14 were found through numerous surveys (Asmus 1999; Gehrke 1992; Johnson and Barlow 1982; O Connor 1986). In 1992, Gehrke recorded male to female sex ratios of 1:1.1 in the Murrumbidgee River Murray crayfish population below the then MLL (80 mm OCL), and a sex ratio of 1:1.7 in the population above the MLL (Gehrke 1992). In 2005, two years after the implementation of the 90 mm OCL MLL, Murray crayfish male to female sex ratios of 0.32:1 and 0.45:1 were recorded in the Murrumbidgee and Murray Rivers, NSW, respectively (McCarthy 2005). Six years following the implementation of the 90 mm OCL MLL our study revealed similar sex ratios, especially in size ranges over 90 mm OCL. Current recreational fishing regulations for Murray crayfish in NSW place higher fishing pressure on males than on females. Females are normally berried from May to September and can become berried at approximately 80 mm OCL. A total ban on taking berried females and a MLL of 90 mm OCL means that during the open season (May-August), legal catches of Murray crayfish by recreational fishers can become dominated by males over 90 mm OCL. The data provided in the reservoirs and the River Murray indicate that the population of Murray crayfish above 90 mm OCL is indeed dominated by females in fished areas whereas there is no difference in the size distribution of crayfish in non-fished areas. Thus, the current fishing regulations appear to be substantially biased in the direction of harvesting male crayfish. 168

191 Similar fishing activities have been shown not to endanger the populations of some crab species. For example, in the Caeté estuary, Pará, North Brazil the mangrove crab (Ucides cordatus) fishery targets mature male crabs whilst females are not targeted due to a lack of market demand for them (Glaser and Diele 2004). Even though larger males are mainly harvested, there are still a greater number of males than females present. The authors suggest that this indicates that a sufficient level of reproductive output is being maintained in the fishery to make it sustainable (Glaser and Diele 2004). In crayfish populations, the removal of large males may impact the population structure through impairment of reproductive success in females (Tulonen et al. 2008). Problems can arise if larger females will not or cannot mate with smaller males. Although it is unknown if larger female Murray crayfish can effectively mate with smaller males, Templeman (1934) found that male American lobsters were unable to mate with larger females. The author also noted that mating success was greatly increased when male lobsters were slightly larger than females (Templeman 1934). A behavioural study is warranted to determine the effects of size on mating behaviour. The effects of a higher number of larger females than males in the population in terms of egg production has been addressed in Chapter 5 (Section 5.4.3) SOM The MLL sets the smallest legal length that a particular species can be retained if caught (Hill 1990). It is one of the most widely and historically used regulation tools in fisheries worldwide (Hill 1990). In NSW, the MLL for Murray crayfish is consistent throughout the state (90 mm OCL). To assess the applicability of the MLL in fisheries management, SOM is often used (Hobday and Ryan 1997). Our logistic model showed that the size class in which 50% of female Murray crayfish were sexually mature in Talbingo Reservoir was 90.8 mm OCL. At the current MLL for NSW, 49% of females had reached sexual maturity in that Reservoir. In comparison, in the River Murray only 39% of females had reached sexual maturity at the current MLL for Murray crayfish. Water temperature differences could be one of the factors associated with the higher SOM found in the River Murray compared to Talbingo Reservoir. The water in Talbingo 169

192 Reservoir was generally colder than that in the River Murray. For example, during the 2010 June sampling period, water temperatures in sampling areas in Talbingo Reservoir varied from 7 to 11 o C. During this same period, River Murray temperatures at our sampling sites ranged from 9 to 13 o C. The effect of water temperature on SOM has been shown to vary between species and can be influenced by temperature related variables such as metabolic demand and food acquisition (Cox and Hinch 1997). For example, both sexes of Fraser River sockeye salmon (Oncorhynchus nerka) were found to have a lower SOM in years when sea surface temperatures were warmer, indicating a slower growth in warmer years (Cox and Hinch 1997). In contrast, higher water temperatures resulted in faster growth and associated higher SOM estimates than lower water temperatures in local New Zealand populations of the southern rock lobster (Jasus edwardsii) (Annala et al. 1980; Bradstock 1950; Street 1969). Interestingly, whereas Annala et al. (1980) found a negative correlation between water temperature and SOM for southern rock lobsters in New Zealand, Gardner et al. (2006) found a positive correlation between these two factors for the same species in Tasmania. In my study, the differences in the SOM between the non-fished sites in Talbingo Reservoir and the fished sites in the River Murray could not be accounted for by fishing pressure alone due to the differences between water temperatures between the two sampling locations. Unfortunately, SOM could not be accurately modelled for Blowering Reservoir due to the low numbers of crayfish caught in that reservoir. Thus, these similar systems also could not be compared for differences in SOM between a fished and non-fished area. Future work comparing similar systems that are fished and non-fished to examine the effect of fishing pressure on SOM would provide useful information for management. 6.5 Conclusion I embarked on a study to assess the effects of recreational fishing on the biology (catch per unit effort (CPUE), size and sex ratios, and size at onset of maturity (SOM)) of Murray crayfish by comparing biological dynamics in a fished (Blowering) and non-fished (Talbingo) reservoir. A low CPUE, poorly represented size class distribution, and few 170

193 berried females in Blowering Reservoir indicated that fishing pressure can have a major impact on populations. A difference in sex ratios and skew towards females, especially in size groups over the legal size limit in the two fished areas demonstrates current catches are indeed dominated by male crayfish. This may indicate a need for a review of current fishing regulations to ensure sustainable future populations of Murray crayfish. 171

194 Chapter 7 Spatial and temporal sampling designs to analyse the population dynamics of a broadly distributed freshwater crayfish Abstract The optimal design of spatio-temporal monitoring strategies for animal populations in order to detect real changes in population dynamics remains a debated topic. Here I use the Murray crayfish (Euastacus armatus), an important recreational fishing recourse in Australian rivers, as a model organism to identify preferred monitoring strategies for broadly distributed and spatially independent species. Specifically, I aim to (a) characterise population dynamics along a major section of the species current range, (b) compare spatial and temporal sampling designs to monitor population dynamics, (c) determine if data from detailed studies in a small part of the species range are transferable to the whole population across a broader geographical area, and (d) provide information for population management. Spatially (26 sites sampled once across 1,250 km river section) and temporally (three sites sampled monthly over a one year duration) focused datasets are compared to estimate key population traits (catch per unit effort (CPUE), length-frequency distributions, sex ratios, and size at onset of sexual maturity (SOM)) for Murray crayfish along a section of the River Murray, NSW. High similarities between population dynamics were realised between the spatial and temporal sampling designs, indicating that either temporal or spatial sampling would serve to monitor spatially-independent populations. However, high variability within sampling designs demonstrates the need to (a) sample at a time of year which maximises CPUE and (b) maximise the number of sites to represent a larger proportion of the population. Based on these outcomes, future monitoring strategies and changes to fishing regulations are proposed to inform conservation and management of this species. 172

195 7.1 Introduction Animal populations are inherently dynamic, with populations varying over time and across broad spatial ranges (Odum and Barrett 2005). Key population dynamics such as abundance, sex ratios, length-frequency distributions, and SOM have been shown to vary over intra- and inter-annual timescales and between meso-habitats, rivers, and catchments (Annala et al. 1980; Bradstock 1950; Cox and Hinch 1997; Elmes 1987; Jenkins et al. 1997). An understanding of how spatial and temporal patterns influence population dynamics has a key role to play in the conservation and management of animal populations (Marsh and Trenham 2008). This is particularly true for species that form the basis of recreational fisheries, where regulations would ideally be continually informed by regular population monitoring to ensure the sustainable regulation of the fishery. In an attempt to account for variability, spatio-temporal sampling designs are routinely employed in monitoring strategies for animal populations. However, debate continues as to the optimal allocation of spatial and temporal replication in order to detect changes in population dynamics over time accurately (De Gruijter et al. 2006). Recently, Rhodes and Jonzén (2011) employed model-based analysis to highlight design principles for detecting temporal trends in the abundance of spatially structured populations. They identified population conditions when monitoring many sites infrequently (i.e. spatial correlation is low, temporal correlation is high) or few sites frequently (spatial correlation is high, temporal correlation is low). They concluded that when the correlation between spatial sites is low and temporal correlation is high, it is best to sample many sites infrequently (Rhodes and Jonzén 2011). Others have reached similar conclusions about sampling strategies (Carlson and Schmiegelow 2002; Roy et al. 2007) and have helped to identify preferred sampling designs for continuous and long-term monitoring strategies. For example, Carlson and Schmiegelow (2002) used long-term avian monitoring data from a Canadian forest and modelling to identify economically viable sampling methods for ecological monitoring programs. The authors found that a decrease in sampling error was evident when an increased number of sites within an area were sampled rather than sampling fewer sites, multiple times within a year (Carlson and Schmiegelow 2002). Roy et al. (2007) assessed 173

196 the efficiency of reduced effort schemes of monitoring 20 widespread butterfly species throughout the United Kingdom. From their results, the authors concluded that sampling fewer times a year at more sites provided similar results to sampling more times at fewer sites but was more cost efficient (Roy et al. 2007). Fisheries managers employ a range of tools to manage fishery resources. These have been divided into three categories, namely input controls, output controls and access controls (McPhea 2008). Input controls include tools such as legal size limits which are measured differently for fish and crayfish species, fishing gear/net restrictions and no takes on berried females. These measures control the amount of fishing effort used and the efficiency of catches through the regulation of fishing equipment. Output controls such as bag limits, possession limits, and limits on prohibited species work directly to restrict the magnitude of the total catch of an individual fisher or of a fishery. Access controls, such as closed areas and closed seasons, limit the areas and times when fishing can occur (McPhea 2008). Many global freshwater crayfish species are under threat, including the Murray crayfish Euastacus armatus (von Martens), which is the second largest freshwater crayfish in the world (Merrick 1993). This long-lived, slow-growing, and late-maturing species is endemic to approximately 12,500 km of the rivers and creeks in the southern Murray-Darling Basin, Australia, representing an extent of occurrence in excess of 150,000 km 2 (Furse and Coughran 2011a; Gilligan et al. 2007). It is evident, however, that Murray crayfish have experienced considerable contractions in distribution and a reduction in abundance over the past 100 years (Furse and Coughran 2011a; Furse and Coughran 2011b; Horwitz 1995). Yet, Murray crayfish are nationally listed as indeterminate and globally as data deficient, highlighting that insufficient funding and resources have been directed toward monitoring (Alves et al. 2010). Monitoring of Murray crayfish populations is clearly necessary to inform management of the recreational fishery given the conservation status of this species. Yet, information on the current status of Murray crayfish across its range remains a recognised knowledge gap (Gilligan et al. 2007; Van Praagh 2003). It is paramount that any monitoring strategies employ robust and efficient sampling designs that have the ability to detect population changes across the broad distribution of a species. According to the principles of Rhodes 174

197 and Jonzén (2011), monitoring strategies for spatially independent species such as Murray crayfish should preferably maximise spatial sampling effort. It is pertinent to consider whether sampling design principles, such as those derived by Rhodes and Jonzén (2011), are appropriate for opportunistically funded, short-term monitoring strategies (i.e. snapshot surveys). The objectives of the present study are to (a) characterise population dynamics along a major section of the species current range, (b) compare spatial and temporal aspects of sampling design, (c) determine if data from detailed studies in a small part of the species range are transferable to the whole population across a broader geographical area, and (d) provide information for population management. Specifically, two datasets were used one spatially focused and one temporally focused to estimate and compare key population dynamics (abundance, length frequency distributions, sex ratios and SOM) for Murray crayfish along a section of the River Murray, NSW. The outcomes of the study could provide useful information to inform management and conservation of the species. 7.2 Methods Study location The River Murray flows 2,530 km from the south-eastern highlands, through the southern Murray-Darling Basin, to the sea at Goolwa (Eastburn 1990). This study focused on a 1,250 km section of that river (1,094 to 2,344 km upstream of the Murray mouth or average mean thread distance, AMTD km) within the middle reaches of the species present range (Fig. 24). Along this section, the river transforms from a small upland headwater river, through a shallow, low gradient river channel flowing through the gently undulating riverine plain to a slow-flowing meandering lowland river (Eastburn 1990). A decrease in altitude from 300 to 47 m AHD occurs along the study section. The river environment along the study section is influenced by several major tributaries (Mitta Mitta, Ovens, Campapse, Goulburn, and Murrumbidgee Rivers) and four major impoundment structures comprising the upland storage impoundment (Hume Dam) and three weir structures (Yarrawonga, Torrumbarry, and Euston weirs). These regulatory structures act to raise and stabilise the water column, typically creating unfavourable conditions for the species (Walker 1985). 175

198 7.2.2 Sampling design Two datasets were used in this study, one with a focus on spatial replication and the other focused on temporal replication. The sampling design of the spatially focused dataset involved the single sampling of 26 sites (i.e. total number of surveys = 26) along the 1,250 km study section daily between 5 July and 30 July The selection of sites was based on a systemic (fixed-interval) sampling design, as it was considered the most appropriate to develop statistically unbiased estimates of population dynamics (King et al. 1981). Initially, the location of the most upstream site was randomly selected within a 100 km stretch (2,275 2,375 AMTD km) known to be upstream of the influence of Hume Dam. A fixedinterval of 50 km, selected to ensure spatial independence between sites for this largely non-motile species (Ryan 2005), was used to determine the location of the remaining sites. To eliminate longitudinal and temporal biases, the order that sites were sampled was randomly allocated using an Excel randomising program. The sampling design of the temporally focused dataset has previously been described in Chapter 5 and Zukowski et al. (2011b). Briefly, three sites (2,094, 2,144, and 2,194 AMTD km) (Fig. 24), that were consistent across both datasets, were sampled monthly between January and December 2009 (12 sampling trips, n = 36). As the three sites were 50 km apart, spatial independence was assured. During each monthly trip, the three sites were sampled on consecutive days, with the sampling order randomised to eliminate temporal and longitudinal bias. 176

199 Figure 24. Location of the sites used in the spatial (1-26) and temporal (3, 4 and 5) datasets to describe Murray crayfish in the River Murray, NSW. Note: site 1 is 2344 ATMD km and a there is 50 km interval between sites (site 26 is 1094 AMTD km) Sampling protocol A standardised sampling protocol, as recommended by Gilligan et al. (2007), was employed with some modifications across both datasets. At each site on each sampling trip, a 2 km stretch that encompassed the variety of available habitat types was selected. Twenty single hoop nets (700 mm hoop diameter, 13 mm mesh) baited with ox liver, were deployed over the 2 km stretch and were checked hourly for a total of three hours (60 hoop net hauls per site). The catch was recorded as catch per net per hour in order to standardise effort, with each net relocated after each haul. Data recorded from each net set comprised date, position (latitude and longitude), time set and time retrieved. The catch data recorded comprised number of Murray crayfish, OCL (measured from the rear of the eye socket to the middle of the rear of the carapace) to the nearest 0.1 mm, weight (to nearest 1 g), sex, the maturity stage of adult females (stages 1 3) (Turvey and Merrick 1997e), and whether females had eggs (in berry). All sampling occurred during daylight hours Determination of population dynamics A number of variables were used to compare the two datasets. Abundance was standardised as catch per unit effort (CPUE), here defined as the number of individuals caught per net per hour in order to standardise sampling effort. Length-frequency distributions were 177

200 developed using 5-mm-OCL size classes. Sexual maturity of females was ascertained by the presence of ovigerose stage 3 setae or presence of eggs (Turvey and Merrick 1997e). The distribution of sexually mature females across the 5-mm-OCL size classes was used to estimate the size at onset of sexual maturity (SOM) according to the following logistic equation (Hobday and Ryan 1997): M = 100 / [1 + (L / L 50 ) b ] where M is the percentage of females in a size class, L is the OCL (mm), L 50 is the length at which 50% of females are mature (SOM), and b is a constant. The sex ratio is estimated through comparison of the number of males to females, across all size classes, and below and above the minimum legal limit, (MLL) (90 mm) of the recreational fishery Data analysis A two sample Kolmogorov-Smirnoff test (KS-test) was used to test whether there was a significant difference in the OCL frequencies between male and female crayfish in the data obtained through the spatial and temporal surveys. A KS-test was also used to analyse whether there were significant differences in the OCL for each sex between data from the spatial and temporal surveys. In each instance, the KS-test was used to determine if the two datasets differed significantly as this test does not make an assumption about the distribution of the data (non-parametric and distribution free). Size structure analysis (length-frequency histograms) was developed. Chi-squared analysis was used to ascertain whether Murray crayfish sex ratios differed from normal distributions. A chi-square test for the comparison of two proportions (from independent samples) was used to determine whether sex ratios differed between spatial and temporal sampling design data distributions. A G-test for goodness-of-fit was used to compare between the numbers of individuals found below and above 90 mm OCL in both the spatial and temporal datasets. Comparisons between the spatial and temporal datasets in overall abundances (CPUE) (individuals per net per hour), the SOM 50, and the number of sexually mature females in berry observed in July were undertaken using a t test. 178

201 7.3 Results Summary of population dynamics from spatial dataset The spatially focused dataset included a total of 383 Murray crayfish (232 females (44 berried), 151 males) between mm OCL and 32 1,178 g, from 1,319 crayfish fishing hours. Across the 26 sites, abundance was highly variable, ranging from 0 to 3.15 individuals per net per hour. The highest CPUE was recorded at sites 1,594, 2,044, 2,094, and 2144, with mean numbers of 0.58, 0.50, 1.58, and 0.95 individuals per net per hour, respectively. No crayfish were sampled at three sites (1,144, 1,294, and 2,244 AMTD km) (Fig. 25). The overall CPUE for the spatially focused dataset was 0.29 individuals per net per hour (females = 0.176, males = individuals per net per hour) CPUE (Ind h -1 ) River km Figure 25. Murray crayfish abundance (CPUE) (Individuals per net per hour) along the 1,250 km sampled River Murray stretch in the spatial sampling dataset, 2009 (n = 383). 179

202 The OCL size frequencies between males and females in the full 1,250 km reach for all size classes were significantly different (KS-test, D = 0.165, P = 0.012) (Fig. 26). These differences stem from the significantly skewed male to female sex ratios. Overall, the sex ratio was significantly skewed towards females (0.65:1) as revealed by chi-square test of goodness-of-fit with Yates continuity correction (only two categories present), (χ 2 = 16.71, d.f. = 1, P < ) and the significantly greater proportion of females greater than 90 mm OCL compared to males (male to female sex ratio is 0.27:1) (χ 2 = , d.f. = 1, P < ) (Table 27). From the total number of individuals captured (383), 85% of individuals were found to be < 90 mm OCL (327 individuals). Significantly higher numbers of individuals < 90 mm OCL were caught compared to those 90 mm OCL (Gtest, G = , d.f. = 1, P < ). 180

203 50 (a) 40 Frequency (b) 40 Frequency Occipital carapace length (mm) Figure 26. OCL size frequency distribution for Murray crayfish populations taken from (a) spatial (females n = 232, male n = 151) and (b) temporal (females n = 248, male n = 173) datasets from the River Murray, Australia. 181

204 Table 27. Summary and statistical comparison between spatial and temporal datasets describing sex ratio of Murray crayfish populations in the River Murray, NSW. Sex ratio (OCL mm) All size classes M Spatial dataset Temporal dataset Statistical comparison F Ratio (M:F) M F Ratio (M:F) Difference (%) P value % < 90 mm % mm % Of the 232 female Murray crayfish ( mm OCL) sampled in the spatial dataset, 54 were classed as sexually mature, ranging between 79 and 136 mm OCL. No immature females were found 97 mm OCL. The logistic model, fitted to the proportion of mature females in each 5 mm OCL size class, resulted in an estimated SOM of mm OCL (r 2 = 0.99; n = 18 size classes) (Fig. 27). At the MLL (90 mm OCL), 36% of female Murray crayfish were sexually mature and 100% were sexually mature at 110 mm OCL Percentage mature Frequency Occipital carapace length (mm) 0 Figure 27. Sexually mature female Murray crayfish SOM spatial (grey bars and circles) (n = 54) and temporal (black bars and circles) (n = 50) datasets from the River Murray, Australia. 182

205 7.3.2 Summary of population dynamics from temporal dataset Population dynamics for the temporally focused dataset are presented in Chapter 5 and Zukowski et al. (2011b). Briefly, the dataset included a total of 421 Murray crayfish (248 females (29 berried), 173 males) between mm OCL and g, from 1,280 crayfish fishing hours. In general, all population dynamics varied significantly across the sampling year. Abundances, for instance, were high between May to September ( individuals per net per hour but significantly lower during the remainder of the year, individuals per net per hour) (Kruskal-Wallis test, H = 17.28, d.f.= 1, P < ). The number of sexually mature Murray crayfish females also varied significantly across the year (G-test, G = 58.88, d.f. = 11, P < ), but sexually mature females were observed in most months (except January, February, and March) Comparison between the two datasets Comparison of the spatially and temporally focused datasets revealed similar estimates of population dynamics (Table 28). Overall abundances (CPUE), for instance, were 0.29 individuals per net per hour in the spatial dataset compared to 0.33 individuals per net per hour in the temporal dataset, a non-significant difference (t = 0.354, d.f. = 1076, P = 0.724). Further, statistically similar (females D = 0.065, P = 0.681; males D = 0.068, P = 0.843) and normally distributed (P > 0.05) length-frequencies and mean lengths (females 78.0 mm vs mm OCL; males 73.0 mm vs mm OCL) were realised for females and males from the spatial and temporal datasets, respectively. The SOM 50 for the spatial (90.82 mm OCL) and temporal (91.77 mm OCL) datasets did not differ significantly (t = 0.261, d.f. = 19, P = 0.797) (Table 28). Similarly, there were no significant differences between the skewed sex ratios observed in the two datasets, when compared across all size classes (χ 2 = 2.067, P = 0.150), individuals below (χ 2 = 0.008, P = 0.931) and above (χ 2 = P = 0.054) the MLL (90 mm). A lower proportion of sexually mature females were in berry in the temporal dataset (53%) compared to the spatial dataset (86%) when all fishing months were compared. The lower number of berried females found in the temporal dataset would be expected as females are only in berry from May to October, whereas sampling was conducted across the year in the 183

206 temporal dataset. When the month in which the spatial sampling was conducted was compared (July) across both datasets, no significant difference in the number of sexually mature females in berry are observed (temporal, 81%, spatial, 86%; t = 0.461, d.f. = 71, P = 0.646). Table 28. Summary and statistical comparison between spatial and temporal datasets describing demographics of Murray crayfish populations in the River Murray, NSW. Population demographic Overall abundance (CPUE) Statistical Analysis t-test Spatial dataset Temporal dataset Statistical comparison P value 0.29 ind/net/hr 0.33 ind/net/hr OCL SOM 50 Sex ratio (M:F) Sexually mature females in berry (during July) two sample Kolmogorov- Smirnoff test t-test chi-square test for the comparison of two proportions t-test mm mm mm OCL mm OCL :1 0.7: % 86% Discussion Murray crayfish population dynamics An understanding of the dynamics that define animal populations is necessary to inform conservation and management (Marsh and Trenham 2008). Yet, for many species, insufficient information is available to make sound management recommendations to ensure sustainable populations (Gilchrist et al. 2005). In the present study, I address this deficiency for Murray crayfish by describing two datasets, one where sites were sampled each month over a year and the other that sampled 26 sites across a 1,250 km section of its southern Murray-Darling Basin distribution. This study is the most comprehensive 184

207 assessment of Murray crayfish populations published to date. This is particularly important as both the national and global conservation status of the species indicates insufficient monitoring (Alves et al. 2010). The specific focus of the present study was to compare key population dynamics between spatial and temporal datasets. Even though Murray crayfish population dynamics vary across time and space, there was no significant difference in the overall parameter estimates obtained from the spatial and temporal datasets. The overall abundance of Murray crayfish was low (0.29 and 0.33 individuals per net per hour spatial and temporal datasets, respectively), but the population structure was broad, with individuals sampled across a wide size range (OCLs of and mm, spatial and temporal datasets, respectively). Estimates of SOM 50 (90.82 and mm OCL, spatial and temporal datasets, respectively) confirm a slow-growing and maturing species, relative to other crayfish species (Momot et al. 1978; Nyström et al. 1999). Male to female sex ratios were significantly skewed ( : 1) towards females, with greater discrepancy above the MLL ( :1) suggesting increased fishing pressure on males (as females with eggs are fully protected). Finally, a high proportion of mature females (81% and 86%, spatial and temporal datasets, respectively) were in berry during the peak breeding period (July). Taken together, the datasets depict a Murray crayfish population with low abundance, patchy distribution, and significantly skewed sex ratio (toward females) Comparison of spatial and temporal monitoring strategies Monitoring strategies must balance spatial and temporal sampling to account for the inherent variability observed in animal populations. However, the optimal allocation of spatial and temporal sampling necessary to characterise key population dynamics is poorly defined. Comparing between spatial and temporal biological dynamics can provide information for the most economical and effective distribution of sampling effort (Matthews 1990). Theoretical analysis relating to sampling variance by Rhodes and Jonzén (2011) indicated that monitoring strategies to detect temporal trends in spatially independent species should preferably maximise spatial sampling effort. The authors argued that when the correlation between spatial sites is low and temporal correlation is high, it is best to sample many sites infrequently (Rhodes and Jonzén 2011). 185

208 I evaluated the theoretical principles of Rhodes and Jonzén (2011) in the field, testing the assumption that there is a difference in the estimates of key population dynamics obtained between short-term spatial and temporal monitoring strategies. Despite significant spatial and temporal variability, comparable estimates of the Murray crayfish population dynamics were obtained between the two datasets. It could be concluded that either temporal or spatial sampling would serve to monitor spatially-independent populations. However, due to the high variability found in CPUE between different times of the year (temporal sampling) and between sites (spatial sampling), two points need to be considered. First, it is important to sample at a time of year to maximise catch as catchability changes over the yearly cycle. For example, highest rates of capture of Murray crayfish occurred during cooler months (May September, individuals per net per hour), but few individuals were recorded during warmer months (November March, 0.2 individuals per net per hour). Second, given the high spatial variability it is important to select temporal sites that have sufficient populations to be adequately representative of the population. This will enable statistical power to be increased. This second point supports the theoretical work conducted by Rhodes and Jonzen (2011) and demonstrates that when abundances are spatially independent, the best approach may indeed be to increase spatial replication. These guidelines are effective for research questions aimed at generating information about population parameters such as sex ratios, size frequencies, SOM, habitat etc. However where questions are posed about the overall abundance of Murray crayfish in a region, then a study which encompasses the first point (timing of sampling) but not the second point (site selection with higher abundance) should be adhered to. The majority of previous studies that have focused on temporal or spatial variability have compared variability within a temporal dataset or within a spatial set or both with mixed findings, but few studies have compared population dynamics directly between temporal and spatial datasets. The majority of these studies found variation in the dynamics of fish species at a temporal and spatial scale, with increased variation generally found at the spatial scale. For example, Magalhaes et al. (2002) compared fish traits, including abundance and species composition, across 166 sites in south-west Portugal. The authors found geographical differences in the number of fish recorded between sites with increased numbers of fish found in larger streams and in downstream reaches (Magalhaes et al. 186

209 2002). The authors analysed a broader geographical area than the one analysed in the present study, thus this may account for the higher spatial variability that they found. In north central Texas, fish sampled monthly at seven sites revealed that the abundance of individual species was more variable spatially among sites than temporally at individual sites (Meador and Matthews 1992). In New Zealand, temporal and spatial variation in the biological traits of reef fish fauna were investigated over a 12 year period (Choat et al. 1988). The researchers identified a marked spatial variation which was often found at localized scales and concluded that there was a higher magnitude of spatial variation than temporal variation (Choat et al. 1988). Adams et al. (2004) assessed spatial and temporal variation in fish assemblages over 17 months in three northwestern Mississippi streams. High variability was found at the species level in both spatial and temporal sampling methods. However, at a higher community level, fish assemblages maintained temporal characteristics which were stream dependent (Adams et al. 2004). The comparison of variability between studies investigating fish assemblages across temporal and spatial variances is difficult as fish assemblages are influenced by a number of interacting factors including the hydrologic regime, geoclimatic region, type of channel, and the past magnitude and frequency of natural and man-induced disturbances (Grossman et al. 1998; Schlosser 1985). Although the studies discussed here demonstrate the variation in fish population dynamics at a spatial or temporal scale, it is difficult to compare these to studies of variability to Murray crayfish as the majority of crayfish species, unlike most fish species, do not move long distances. Although biological traits were compared directly between temporal and spatial datasets, these studies examine spatial and temporal variability within sites or over time scales. To my knowledge this is the first study to compare biological traits between temporal and spatial datasets of a crayfish species Transferring data from detailed studies across a broader geographical area Threats to biodiversity have resulted in an international call by governments to achieve a significant reduction in the current rate of biodiversity loss at global, regional, and national 187

210 levels (United Nations Environment Programme 2002). These broad geographical agreements emphasise the need for effective large-scale spatial monitoring programs in order to assess population trends (Balmford et al. 2005), differentiate between humaninduced and natural influences (Spellerberg 1991), and provide information at scales appropriate for use in policy (Urquhart et al. 1998). However, large scale monitoring programs are difficult to undertake effectively due to financial constraints and are therefore uncommon (Carlson and Schmiegelow 2002; Committee on Environment and Natural Resources 1996; National Research Council 1995). Thus, it is critical that studies address the challenge of relating processes and patterns from small-scale sampling to conclusions at larger-scales in order to assist in management of species at larger scales (Thrush et al. 1997b). The initial motivation for the comparison presented in the present study was to assess whether temporally focused sampling (i.e. fewer localised sites sampled over a longer time period) could accurately characterise broader spatial population dynamics and thus be extrapolated to a broader geographical area. The results obtained demonstrate that data from three localised sites in a small part of the Murray crayfish population in the River Murray are indeed comparable to that found on a larger scale that makes up a significant proportion of the Murray crayfish distribution in the River Murray. From this I conclude that localised sampling can indeed be transferred to the whole population across a broader geographical area. As freshwater crayfish species have a history of limited funding and resource allocation, many decisions are likely to be constrained by resources (funding, personnel) available to allocate to the monitoring strategy. Based on the outcomes of the present study, when resources are limited conducting monitoring strategies on a smaller geographical scale may provide adequate information on the targeted species to be used for policy decisions. These conclusions are, therefore, positive and encourage at least some monitoring investment. Previous authors have noted the important challenges of extrapolating or scaling up data from a small scale to a larger scale for conservation biology and ecology (Brose et al. 2005; Thrush et al. 1997a; Thrush et al. 1997b). For example, Thrush et al. (1997a) combined small-scale experimental sampling with spatial mapping to determine the density effects of 188

211 large specimens of a tellinid bivalve (Macomona liliana Iredale) on associated macrofauna in 0.25 m 2 experimental plots and extrapolated this to an area over 12.5 ha. Comparisons between small scale sampling and the larger area showed similarities in density and total numbers of individuals. In parallel with our results, the researchers concluded that smaller scale monitoring not only provided similar results to those obtained at a larger area but they also provided important information about intrinsic processes that operate within the smaller scale (Thrush et al. 1997a) Implications for monitoring of Murray crayfish In terms of future monitoring strategies for Murray crayfish to asses changes in population parameters such as sex ratios, size frequency distributions, SOM, and in the abundance and distribution of Murray crayfish, I recommend a five-year sampling cycle where broad spatial replication is the focus during years one and five to provide broad assessment across the species range and identify sites that would be the focus of temporally focused sampling in years two, three, and four. For Murray crayfish, the first and fifth years might involve the single sampling of spatial sites distributed across the southern Murray-Darling Basin (n = 50 or 100). In the intermediate years, a sub-set of the spatial sites could be sampled monthly between May and September, when water temperatures are lowest and abundances are highest, as observed by Chapter 5 and Zukowski et al. (2011b). The proposed monitoring strategy would help to detect both spatial and temporal changes in Murray crayfish population dynamics. Although the outcomes of the present study are based on the most comprehensive assessment of Murray crayfish population dynamics ever published, several cautionary notes are necessary. First, the spatial extent, while broad, did not account for other important populations in the southern Murray-Darling Basin, including the Murrumbidgee River. Second, the temporal extent represents only a single year and may not adequately reflect long-term patterns in Murray crayfish population dynamics. Third, all sampling was carried out during daylight hours despite freshwater crayfish species often showing increased nocturnal or crepuscular activity (Holdich 2002). This aspect of sampling design was employed for logistical reasons and also as Murray crayfish appear not to exhibit diel fluctuations in activity (Ryan 2005). 189

212 7.4.5 Implications for management of Murray crayfish Although many Murray crayfish remain across the southern Murray-Darling Basin, the low and patchy abundances observed across both datasets are of concern. These findings and previous work highlighting the low movement range of Murray crayfish (Ryan et al. 2008) highlight the vulnerability of spatially independent sub-populations along the River Murray. Indeed, Murray crayfish were largely absent from weir pool environments (only one individual sampled in four sampled sites), providing further evidence that weirs are limiting the distribution and abundance of the species (McCarthy 2005). As such low numbers of Murray crayfish were found in weir pool environments, changes in fishing regulations may not be an adequate enough management solution to improve the sustainability of Murray crayfish in these environments. Here, other solutions may need to be investigated relating to habitat features. Further, low abundances at other sites suggest that localised extinctions, as has occurred along the 1,076 km of the lower River Murray (Geddes et al. 1993), may occur in the future. Although unpopular, the closure of the Murray crayfish fishery in low abundance sections of the River Murray may be required to ensure sustainability of the species. Potentially, regulation could involve closure of the Murray crayfish fishery every second or third year to balance the need to reduce fishing pressure but sustain the support of recreational fishers who have been shown to be important sources of information regarding the fishery (Zukowski et al. 2011a). Indeed, in Chapter 3 recreational fishers of Murray crayfish in NSW proposed a total closure of the Murray crayfish fishery as the main change required to fishing regulations to help ensure the sustainability of the species Implications for monitoring and management of other spatially independent species Spatially independent populations can have a high vulnerability to environmental disturbances such as river regulation and degradation, pollution, runoff and blackwater events (King et al. 2012). For example, blackwater events which become hypoxic to aquatic organisms (Hladyz et al. 2011; Whitworth et al. 2012) can lead to significant decreases in the abundance of sub-populations of species (King et al. 2012). Thus continuous and long-term monitoring strategies should be employed to detect real change in 190

213 population dynamics over time for broadly distributed and spatially independent species (Callahan 1984). Monitoring strategies of this nature are routinely recommended to inform strategic management of many species around the world (Furse and Coughran 2011c; Gilligan et al. 2007; Horwitz 1995; Horwitz 2010). The present study not only highlights the benefits that can be gained, but also helps guide the design of monitoring strategies for Murray crayfish and other broadly distributed and spatially independent species. For such species (Ricklefs 2012), especially where resources or economic variables are constricted, designing monitoring methods on a smaller geographical scale may provide adequate information on the targeted species to be used in the management of the resource. Further, although the high comparability between spatial and temporal monitoring methods may indicate that either of these methods may be justified to monitor spatially-independent populations, the high variability between sampling times and sites found in our study and in other studies (Adams et al. 2004; Choat et al. 1988; Magalhaes et al. 2002; Meador and Matthews 1992) indicate a need for caution to be exercised at a species specific level. 7.5 Conclusion Monitoring strategies to obtain biological data need to be efficient and accurate due to personnel and economic constraints for research. Here I used Murray crayfish as a model organism to compare spatial and temporal monitoring designs in the River Murray in order to ascertain population traits, whether the two sampling methods are comparable, and whether data from small scale sampling can be extrapolated on a larger geographical scale. Comparable results were found between the two monitoring strategies with a Murray crayfish population of low abundance, patchy distribution, and significant skewed sex ratio (toward females). The use of spatial or temporal monitoring strategies provides data that is representative of a general Murray crayfish population, with certain caveats. Further, the data from small scale sampling could be extrapolated to larger geographic regions. 191

214 Chapter 8 Discussion 8.1 Key findings For effective and sustainable management of natural resources, reliable information is required on population dynamics, biological traits, and associated harvests to ensure that the amount and size of the catch does not endanger survival of the population (Lebreton et al. 1992; Ludwig et al. 1993). The main source of information used in natural resource management is ecologically based. Previous studies have also used local ecological knowledge (LEK) on a global scale to provide quick and economical baseline information for the management of natural resources (Silvano and Begossi 2005; Silvano et al. 2006; Silvano and Valbo-Jørgensen 2008; Valbo-Jorgensen and Poulsen 2000). There is increasing recognition that the use of LEK can be a valuable asset to complement scientific data for use in natural resource management (Berkes et al. 2000; Chemilinsky 1991). The use of LEK in commercial fisheries is becoming increasingly documented (Baelde 2001; Bergmann et al. 2004; Silvano and Begossi 2005; Silvano and Valbo-Jørgensen 2008); however its use in recreational freshwater fisheries is not common. One of the findings from my interviews with recreational fishers was that fishers did not perceive the Murray crayfish fishery to be sustainable. This was mainly due to the fishers perception that over time there had been a decrease in Murray crayfish abundance and distribution, and a change in size and sex ratios. Previous studies have demonstrated that ignoring such vital fisher LEK about the sustainability status of a fishery can put fishery resources at risk and even lead to fishery population collapses. Possibly the most well known example of this occurring was in the north Atlantic cod fishery. Fishery biologists and managers did not take into account inshore cod fishers arguments that the cod spawning stocks had decreased to significantly low levels (Harris 1998; Neis 1992). Fisher LEK was ignored and no management changes to regulations were put into place. This led to the collapse of the Atlantic cod fishery (Harris 1998; Neis 1992). An example on a smaller scale occurred in the Solomon Islands with the largest commercial fishery, the skipjack tuna (Katsuwonus pelamis) fishery (Johannes et al. 2000). In the early 192

215 1980s, local fishers in the Western Province villages argued that baitfish numbers, which were a key prey fish for the larger predatory fish in their catch, were significantly decreasing in areas where commercial bait fishing was permitted. The fishers stated that this was leading to low numbers of large fish that they could harvest. An investigation by the Solomon Island Government in the mid-1980s concluded that there was only a minimal impact of the commercial bait fishery on the subsistence fishery, and therefore there was no need for further investigations, management plans, or changes in fishing regulations. However, in , further research conducted in the Western Province as part of a larger project used a more detailed methodology and found contradicting results to those found by the government study. The more recent results were the same as those of the fishers in the early 1980s (Hamilton 1999). With ongoing commercial bait fishing, local fishers maintained that their catches were continuing to decline in the late 1990s, and this was supported by commercial catch data. However, management did not change practices as a response to fisher LEK and new research investigations, leading to the decrease in the sustainability of the skipjack tuna fishery (Aswani 1997). Although these examples provide clear evidence of the detrimental outcomes that can occur if fisher LEK is not used in resource management, the use of fisher LEK in management is still the exception rather than the rule. The fishers from my study also felt that their LEK was not being used in the management of the Murray crayfish fishery. They argued that this was one of the reasons why the Murray crayfish fishery was not sustainable. Indeed, fishers wanted a change in management to ensure that there was an increase in fisher engagement, communication, and education. Previous studies have demonstrated the importance of improving communication between fishers, scientists, and managers, and this has been recognised by all involved parties (Baelde 2001; Mackinson 2001; Moore 2003; Taylor 1998). The inclusion of resource users in management processes has also been identified as an important step in achieving sustainable local common pool resources (Ostrom 1990). This step helps to ensure that local users perceive the legitimacy of procedures, policy making systems, and regulations to be enhanced (Nielsen and Mathiesen 2003; Tyler 1990; Winstanley 1992), and increases the support of the regulations based on the science (Bergmann et al. 2004). 193

216 Many of the recreational fishers interviewed did not perceive that the fishing regulations for Murray crayfish were legitimate. Where regulations are not perceived as legitimate, the compliance rate by local users can decrease (Nielsen and Mathiesen 2003). Fishers stated that they perceived the compliance rates to be an average of 43% among fishers, and they reported that they themselves had an average compliance rate of 47%. Compared to other studies of inshore fisheries, these compliance levels are quite low. For example, compliance rates for ground fish such as lobster and scallop in Rhode Island and Massachusetts, New England, were 50% to 90% (Bean 1990; Sutinen and Gauvin 1988; Sutinen et al. 1990). In Lake Victoria, Africa, the world s second largest freshwater body of water, compliance rates were 81% (Eggert and Lokina 2008). In NSW, compliance rates of approximately 90% have been recorded for recreational fishers in both coastal waters and fresh waters (NSW RFFTEC 2005; RFSTEC 2010). The interviews I conducted also revealed that fishers wanted to see a total closure of the Murray crayfish fishery for two to five years as the main change to fishery regulations and management. In comparison, previous researchers have argued that common property resource users generally only provided information, made decisions, invested in improvements, and adhered to policies that increased their own profits in the short-term, and had no long-term view to preserve resources from over-exploitation (Gorden 1954; Harding and Fisher 1999; Ostrom and Hess 2007). Previous researchers (Bergmann et al. 2004; Pederson and Hall-Arber 1999) also found that few fisher respondents were willing to provide information that could result in management developments that had potential to negatively impact on their entitlement to fish. 8.2 Reliability of fisher LEK The reliability of LEK is often questioned because there is a lack of peer reviewed articles that incorporate LEK into the biological literature (Nadasdy 2003), the methodology that is used to obtain LEK is generally qualitative (Mauro and Hardison 2000), and there are few studies that demonstrate that LEK can produce similar outputs to biological data. As the reliability of LEK is often questioned, the application of it as a tool for natural resource management continues to be debated (Mauro and Hardison 2000). Unreliable data can lead 194

217 to inaccurate interpretations and flawed decision making (Ludwig et al. 1993; Walters and Hilborn 1978). The reliability of data can be increased if comparable outcomes are produced by different data generating methods (Huntington et al. 2004a). Comparing data between two independent sources of information, such as LEK and scientific methods, could increase confidence and depth of knowledge in both approaches (Huntington et al. 2004a). However, this comparative approach is difficult to achieve in practice because LEK and scientific understanding are usually gathered from different locations, time periods, and wildlife populations (Huntington et al. 2004a). From my data, the strong comparability of the three data generating methods (fisher interviews, fishing catch cards, and Murray crayfish field surveys) indicated that recreational fisher LEK is a reliable data generating source that can detect population changes at an early stage and enable proactive and efficient management. Previous studies have examined the general benefits of LEK for management practices (Ainsworth and Pitcher 2005; Baelde 2001; Baticados 2004; Bergmann et al. 2004; Da Silva 2004; Grant and Berkes 2007; Huntington et al. 2004b; Johannes et al. 2000; Ruddle 1994). However, only a handful have attempted to test the reliability of this type of information (Gilchrist et al. 2005; Huntington et al. 2004a). For example, Gilchrist et al. (2005) compared four cases of LEK with independent biological investigations of marine birds from the same populations. The researchers found the reliability of LEK to range between low, moderate, high, and very high for the four species examined, based on the comparability with scientific investigations. They concluded that although there could be limitations associated with LEK, namely the need for it to be used in conjunction with science for best reliability, LEK should play an important role in wildlife management and conservation biology (Gilchrist et al. 2005). 8.3 Better knowledge of the biology of Murray crayfish The three data generating methods (fisher interviews, fishing catch cards, and Murray crayfish field surveys) indicated a lower frequency of individuals above the current MLL (90 mm OCL) and skews in the sex ratios of larger crayfish (> 90 mm OLC) towards 195

218 females in recreationally fished waters. These results are comparable to heavily fished crayfish species with fishing regulations in place to protect berried females. One sex generally becomes exploited more than the other, and the sex ratios become skewed towards one sex, especially in larger animals. For example, male J. edwardsii account for 80% (Breen and Kendrick 1997) and male J. lalandii account for almost 100% (Pollock 1986) of the landed catch in certain areas of New Zealand and South Africa, respectively. Where large males are targeted through fishing and are rare, egg production can be limited through sperm-limited female fecundity (MacDiarmid and Butler 1999). Further, the lower numbers of males found above the MLL could result in increased difficulty for females to find suitable mates and lead to the low percentage of berried females sampled. This was evident in my studies, with only 58% of sexually mature females found to be in berry during the months in which females were sexually active (May to November). Size at onset of sexual maturity (SOM) is often used to assess the applicability of the MLL in fisheries management (Hobday and Ryan 1997). SOM is generally defined as the size or size class at which 50% of individuals in a sample are mature (Annala et al. 1980). The SOM data and associated logistic model revealed that only 39% of female Murray crayfish were sexually mature at the MLL (90 mm occipital carapace length) set by current fishing regulations. The size class in which 50% of female Murray crayfish were sexually mature was 91.8 mm OCL. Hill (1990) argued that the closer the MLL is set to the SOM, the more protection it offers reproductive stock and thus it has a higher chance of increasing the reproductive output through size limits. The author suggested that setting the MLL at the smallest size at which any of the individuals mature or at a size where the majority of individuals are mature will allow for differences in SOM within the population, and thus increase protection. Further, setting the MLL above that of first spawning would allow females to spawn more than once and increase numbers of eggs (Hill 1990). As SOM can be affected by geographic (Hobday and Ryan 1997) and temporal (Annala et al. 1980; Bradstock 1950; Street 1969) factors, further research is warranted to gather information for the Murray crayfish fishery in other regions of this species range outside of NSW. The open season for Murray crayfish is from 1 May to 31 August each year. Females first came into berry 16 days after the commencement of the open fishing season (May 16). This 196

219 occurred with the onset of a drop in water temperatures to 13 o C. Interestingly, similar results were found by O Connor (1986) in the Murrumbidgee River at Narrandera more than 25 years ago. He reported that mating took place in early to mid May at temperatures of o C, and by late May nearly all sexually mature females were in berry. Thus, although fishing regulations that include a ban on taking berried females have been in place in NSW for over 20 years, under current fishing regulations females that are not yet in berry could be legally taken at the commencement of the fishing season. In the south Florida spiny lobster (Panulirus argus) fishery, the majority of spawning (77-78%) occurs during the closed season (Lyons et al. 1981), and in northern Lake Michigan the closed season for walleye species (Sander vitreus) is in effect during their spawning season and so this prevents fishers taking any walleyes while they are spawning (Crowe 1962). During the handling of berried females, an average of 1.3 eggs dropped off when the tail was left closed, and 3.9 when the tail was opened. To my knowledge there are no previous studies showing the effects of handling on egg loss in crayfish in field experiments. However, Policar et al. (2004) compared the effects of controlled laboratory conditions with outdoor ambient conditions on the noble crayfish (Astacus astacus L.) egg hatching success, and growth and survival of juveniles. The researchers found that when crayfish were left in outdoor ambient conditions, all females retained their eggs. However, in controlled laboratory experiments where handling was increased, two female crayfish lost all their eggs (Policar et al. 2004). Jones and Coulson (2006) investigated the effects of handling-induced mortality on crayfish during mark-recapture studies in an endemic freshwater crayfish from Madagascar (Astacoides granulimanus). The authors found that the survival of crayfish was significantly affected by handling during mark-/recapture surveys and this was more significant in larger sized individuals (Jones and Coulson 2006). Individual crayfish can be recaptured many times during an open season, especially in popular fishing areas. Where size limits and/or a protection of reproductive stock protects larger individuals, and results in increased numbers of larger females present in a population, as I found in my investigations, these individuals could be more at risk of handling stress and mortality associated with recapture. This is an important point for managers to consider as larger individuals generally carry higher egg numbers and have a 197

220 larger reproductive output. However, handling-induced mortality could occur to any sized individual and this mortality, if unquantified, can have a major impact on achieving the optimal harvesting management goals (Zheng et al. 1997). 8.4 Effects of fishing Setting optimal management goals can be difficult as there is often inadequate information available about systems. This is especially evident in the general lack of published articles about the natural state of marine and freshwater systems prior to the introduction of fishing. The addition of fishing pressure to a non-fished system can lead to major changes in the structure of fish communities (Jennings and Kaiser 1998). Where information about a system prior to the introduction of fishing is not available, comparing between fished and non-fished areas can provide detailed information about the effects of fishing pressure on biological dynamics (Freeman 2008). Such information is important for the management and protection of species (Freeman 2008). Specifically, this type of information can provide comparisons between natural and fished populations on abundance, size and sex ratios, fecundity, SOM, growth rates, nutritional condition, and bacterial infections associated with handling (Freeman 2008; Gardner et al. 2006). The comparison of the non-fished Talbingo Reservoir and the fished Blowering Reservoir revealed significant differences in the abundance, size frequency distribution, sex ratios, and SOM of Murray crayfish populations between these sites. These differences highlight the effects of fishing and the associated fishing regulations and the possible effects of drought conditions on the Murray crayfish population in Blowering Reservoir. Talbingo Reservoir had a higher abundance of Murray crayfish, well represented size frequency distribution, and approximately even sex ratios, whereas Blowering Reservoir had a low abundance of Murray crayfish, poor size frequency distribution, and uneven sex ratios. These results are important to consider in management, especially as the five year closure of Blowering Reservoir is to be reviewed in Similar results were found in the fished sites in Blowering Reservoir and the River Murray, and these two sites differed from the non-fished Talbingo Reservoir. In previous studies comparisons have been made between fished and non-fished areas in marine environments, especially with respect to Marine Protected Areas (MPA) (Davis and 198

221 Dodrill 1989; Edgar and Barrett 1999; McClanahan and Mangi 2000). For example, Gardner et al. (2006) compared marine lobster species (Jasus edwardsii) in fished and nonfished sites (MPA s) around Tasmania. The effects of fishing were evident in CPUE with lower numbers of lobsters found in fished areas, however no difference was noted for SOM between the areas (Gardner et al. 2006). Few researchers have compared fished and non-fished areas in freshwater environments. Jowett et al. (1998) compared the species composition, abundance, and diversity of fish communities in fished and non-fished sites of New Zealand to identify fish populations that may have formerly existed in these areas, and to examine the effects of fishing pressure on fish communities. Comparisons of the densities of three whitebait species (Galaxias spp.) and one longfinned eel species (Anguilla dieffenbachii) between fished and non-fished streams revealed no significant differences (Jowett et al. 1998). However, species richness and fish diversity were lower in the non-fished sites than in the fished sites. The authors concluded that the comparison of fished and non-fished sites revealed there was no evidence of fishing pressure (Jowett et al. 1998). 8.5 Methods for understanding fish population dynamics Population dynamics of fish populations can vary across spatial and temporal ranges (Odum and Barrett 2005). Spatio-temporal monitoring programs are often used in an attempt to account for this variability. However, there is uncertainty about the optimal allocation of spatial and temporal replication in order to accurately detect changes in population dynamics over time (De Gruijter et al. 2006). Previously, researchers have argued that sampling infrequently at many sites, rather than frequently at a few sites, is likely to provide more efficient and effective data. For example, in the United Kingdom, the monitoring and modelling of 20 widespread butterfly species revealed that sampling fewer times a year at more sites provided similar results to sampling more times at fewer sites but was more cost efficient (Roy et al. 2007). Long-term monitoring data and modeling from a Canadian forest showed similar results with a decrease in sampling error found when more sites within an area were sampled fewer times rather than sampling fewer sites, multiple times within a year (Carlson and Schmiegelow 2002). In North central Texas, fish sampled monthly at seven sites revealed that the abundance of individual 199

222 species was more variable spatially among sites than temporarily at individual sites (Meador and Matthews 1992). Rhodes and Jonzen (2011) used model-based analysis and argued that when the correlation between spatial sites is low and temporal correlation is high, it is best to sample many sites infrequently. I evaluated the principles of Rhodes and Jonzen (2011) in the field to determine whether there is a difference between spatial and temporal monitoring strategies. In my study, comparable data were realised for population dynamics (abundance, lengthfrequency distributions, sex ratios, and SOM) between spatially (26 sites sampled once across 1,250 km river section) and temporally (3 sites sampled monthly over a year duration) focused datasets. Although my findings demonstrated that temporal and spatial sampling methods were comparable, CPUE was found to be variable at different times of the year in the temporal survey and between sites in the spatial survey. Thus, sampling at a time of year when catchability is highest and increasing spatial replication would help ensure that the samples are as representative of the population as possible for the resources invested. In Australia, as decisions on fishing regulations are generally made at a state level, it is important to determine whether data from a small part of a species range is transferable to the whole population across a broader geographical area. In my study, the high comparability between data from three localised sites (temporal sampling) and those from a larger geographical area (spatial sampling) showed that the application of data from detailed studies was indeed transferable across a broader geographical area. This is an important factor for the management of natural resources at larger geographical scales (Urquhart et al. 1998), especially given the difficulty associated with undertaking large scale monitoring programs effectively (Carlson and Schmiegelow 2002; Committee on Environment and Natural Resources 1996; National Research Council 1995). The important challenges of extrapolating or scaling up data from a small-scale to largerscale for conservation biology and ecology have been noted in previous studies (Brose et al. 2005; Thrush et al. 1997a; Thrush et al. 1997b). For example, small-scale experimental surveys and spatial mapping of a tellinid bivalve (Macomona liliana Iredale) and 200

223 associated macrofauna revealed that smaller scale monitoring not only provided similar results to those obtained from a larger area but they also provided important information about intrinsic processes that operate within the smaller scale (Thrush et al. 1997a). Comparisons of fish traits across 166 sites revealed geographical differences in the number of fish recorded between sites, with increased numbers of fish found in larger streams in downstream reaches (Magalhaes et al. 2002). This indicated the need for caution when scaling up from small areas to large geographical areas with complex environmental systems. 201

224 Chapter 9 Conclusion 9.1 Summary of major findings The broad aim of this thesis was to explore the impact of fishing regulations on the sustainability of Murray crayfish in NSW from both ecological and social perspectives. Specifically, three questions were examined: Q1, What do stakeholders think about the sustainability of the Murray crayfish fishery? (Chapters 3 and 4); Q2, How critical are the fishing impacts to the sustainability of Murray crayfish? (Chapters 5 and 6); and Q3, What are the best research methods for collecting data to inform management decisions for Murray crayfish? (Chapter 7). Fisher interviews, fisher catch cards, and Murray crayfish field surveys and experiments were used to gather information to address these questions. In Chapter 3 I found that the recreational fishers interviewed generally did not perceive the Murray crayfish fishery to be sustainable. This perception was based mainly on their personal observations of declines in the abundance and size of crayfish caught and changes in the sex ratios. Fishers commented that their perception of the Murray crayfish fishery as not being sustainable was mainly due to a lack of compliance with fishing regulations, inappropriate fishing regulations, catch rates exceeding sustainable levels, and a lack of community engagement and education. Fishers suggested that changes were required to current fishing regulations, regulation enforcement methods, and community education and engagement methods to achieve long-term sustainability of Murray crayfish. The highest ranking change to fishing regulations suggested by fishers was to place a total ban on fishing for Murray crayfish for three to five years in NSW to allow the population to recover. Although fishers suggested that there was a need to engage with them in the management processes to help ensure Murray crayfish populations are sustainable, they largely felt that this was not being achieved. The use of fisher local ecological knowledge (LEK) in fisheries management has long been debated, and to date the use of data provided by fishers is a contentious topic in fishery management. With scientists and managers often concerned about the reliability of fisher LEK, this source of information is still often underutilised. 202

225 Thus, in Chapter 4 I compared fisher LEK, fisher catch data, and scientific data for Murray crayfish size and sex ratios in the River Murray to determine if these data are consistent and if fisher knowledge can be a regarded as providing reliable information for fisheries management. All data sources indicated that there were higher numbers of crayfish < 90 mm OCL compared to 90 mm OCL and the sex ratio of larger crayfish ( 90 mm OCL) was skewed towards females. Fisher catch card and scientific survey data showed the size frequencies of male and female crayfish were significantly different. The strong similarity of results across the three data generating methods indicated that recreational fisher LEK could be a reliable data generating source that could detect population changes at an early stage and enable proactive and efficient management. Fishers suggested that they did not perceive the current fishing regulations to be working or to be accurate. Gilligan et al. (2007) also suggested that a review of fishing regulations for Murray crayfish was a high priority in NSW. Thus, in Chapter 5, I explored the biology of Murray crayfish in a fished river section with specific reference to the implications of these biological traits with current fishing regulations. Four biological dynamics were investigated (SOM, year round catch rates, egg and hatchling timing, and egg dislodgement rates) in a section of the River Murray, NSW. These dynamics underpin three key fishing regulations for Murray crayfish: the MLL, restricted fishing season, and protection of berried females. In Chapter 5, I presented three main findings related to fishing regulations. First, only 39% of female Murray crayfish were sexually mature at the MLL (90 mm OCL) set by current fishing regulations. Thus if management goals are to allow the majority of females a chance to reproduce at least once, the current MLL should be increased. Second, females first came into berry 16 days after the commencement of the open fishing season. Therefore, the open season should be moved to a later date to allow the majority of females to come into berry prior to fishing activity. Third, during handling of berried females, an average of 1.3 eggs dropped off when the tail was left closed and 3.9 when the tail was opened. The commencement of the Murray crayfish season and prospect of fishers to handle crayfish while in berry should be examined. Although numbers of eggs lost during handling were 203

226 low in this study, the long-term effects of continued or rough handling on the recruitment success rate of Murray crayfish eggs are unknown. As the data presented in the early chapters were obtained in fished, spatially localised areas, there was a need to compare those data against data gathered in non-fished areas and on a larger spatial scale. Collecting data in non-fished areas for population dynamics such as abundance, size and sex ratios, fecundity, SOM, and growth rates is important in order to set benchmarks from which management decisions can be guided. Further, comparing between fished and non-fished areas can provide detailed information about the effects of fishing pressure on biological dynamics, information that is vital for the management and protection of species (Freeman 2008). In Chapter 6, the effect of fishing for Murray crayfish in Blowering Reservoir was evident when compared to the non-fished Talbingo Reservoir. For example, the Murray crayfish population in Blowering Reservoir was characterised by a low CPUE, poorly represented size class distribution, and few berried females. In comparison, Talbingo Reservoir supported a population of Murray crayfish with a higher CPUE and a good representation of all captured size classes including juveniles and berried females. Although there was no significant departure from the expected 1:1 sex ratio for each tested size class (<, 90 mm OCL and all size classes) in Talbingo Reservoir, in Blowering Reservoir the sex ratios differed significantly from parity and these were skewed towards females in all size classes, with the skew being most extreme for the size class 90 mm OLC. The focus of the next chapter (Chapter 7) was to determine whether spatial and temporal sampling designs produce the same results and whether data from localised studies were transferable across a broader area. A comparison of Murray crayfish biological dynamics between the spatial and temporal data sets revealed a substantial number of similarities. There were no significant differences in the abundance, size frequency distribution, or sex ratios between the two data sets. Both data sets revealed that the OCL size frequency distributions, and sex ratios between males and females within each data set were significantly different. The SOM for the spatial and temporal data sets did not differ significantly with SOMs of and mm OCL recorded, and 49% and 39% of female Murray crayfish reaching sexual maturity at the current MLL, respectively. In the 204

227 month of July, there was no significant difference in the number of sexually mature females in berry between the temporal (81%) and spatial (86%) data sets. The spatial and temporal sampling regimes reveal high similarities in the biological traits between the two sampling methods. As the two methods provide comparable outcomes, it can be concluded that data from small area sampling can be extrapolated over a larger regional area for decision making purposes. 9.2 Summary of contributions based on knowledge gaps Through this thesis I have provided information pertinent to key knowledge gaps as outlined in the introduction (Section 1.1). Gilligan et al. (2007) recommended that gathering community information on Murray crayfish was a high management priority. In Chapter 3, I provided detailed information on fisher values and attitudes, and LEK, about Murray crayfish and their associated fishing regulations. The use of such information can play an important part in fisheries management, not just for Murray crayfish but for a large range of Australian and international fish species. Although the information collected here is specific to Murray crayfish, it also provides insight into the general values of fishers, the knowledge that fishers have about a fishery, their perceptions of the fishery and why they have these perceptions and their views on how a fishery and fishing regulations can be improved. However, this type of information is still used as the exception rather than the rule in fisheries management as there is a general uncertainty about the reliability of fisher LEK. In Chapter 4, I demonstrated that fisher LEK can indeed provide a reliable source of information. I found a high similarity between Murray crayfish size and sex ratio data obtained through fisher interviews, catch cards, and Murray crayfish field surveys. To my knowledge, data from these three methods have not been compared in freshwater or commercial fisheries literature. Although the methodology for each of the individual sampling techniques was acquired from previous studies, no previous research has compared these three techniques. Further, there is a lack of literature comparing any local and biological data-generating methods for recreational fisheries and the data presented here provides an important step in the management of a large range of Australian and international recreational fisheries. This chapter provided the first comparison of fisher 205

228 LEK from interviews, catch data, and biological information for a freshwater recreationally fished native species. In the next chapter (Chapter 5) I provided detailed information on Murray crayfish biology including SOM, size and sex ratios, and CPUE. This chapter and a published paper provided the first peer reviewed article describing current biological dynamics of Murray crayfish. These data are important to fill in knowledge gaps about Murray crayfish biology and they provide information for fisheries regulation recommendations. As highlighted in the introduction (Section 1.1), information on the current effects of fishing pressure and the current regulations on the distribution, abundance, genetic diversity, length frequency ratios, and sex ratios is currently very scarce but vital for future management of this species. Gilligan et al. (2007) rated the review of the appropriateness of fishing regulations as a high priority. As well as providing information on the biological traits of Murray crayfish, in Chapter 5, I therefore linked these biological traits to fishing regulations for Murray crayfish. This data is also important in the management of other crayfish species at a global scale. Information about size and sex ratios and SOM are vital for fisheries management and are often used to compare between species to determine normalities within systems especially where no pre-fishing data exist. Further the information on the relationship between these biological data and fishing regulations is an important factor which can be utilised in the management of not only crayfish species but a large range of fish species globally. To date, it appears that there are no published or available data on Murray crayfish populations in non-fished waters. This information is important to establish a benchmark for setting management targets. In Chapter 6, I present data on Murray crayfish populations that have not previously been fished and compare these to data from fished areas. I also investigate the findings in terms of management implications for fishing regulations and assess how environmental factors such as different water temperatures or levels can affect population numbers which is an important factor for the management of many fisheries. Gilligan et al. (2007) argued that gaining information on the current status of Murray crayfish throughout their entire range remains the most significant knowledge gap for the species and a high priority research need. In my last research chapter (Chapter 7), I 206

229 examine Murray crayfish populations over a 1,250 km river reach in NSW. Although this does not make up the species entire range, it does constitute a large river section of its range throughout NSW. Further, in Chapter 7, I provide new information on the use of spatial versus temporal research methods and examine which is more appropriate to use. This information can provide an important basis for the methodology of future research in the management of spatially independent crayfish and fish species worldwide. 9.3 Reflection on research methods In this thesis I have used methods from the social and biological sciences. My background is in biological sciences, so in order to effectively undertake the social research component of my thesis, I have learnt new bodies of theory, new research methods and tools, and different perspectives on research. I have also had to investigate how to integrate data from the social and biological sciences. For example in Chapter 4, I used and compared three different data collection methods (interviews, catch cards, and hoop net surveys) from social and biological fields to determine whether fisher knowledge was an accurate source of information for fisheries management. For the interviews, I used a semi-structured qualitative face-to-face approach with 30 fishers. Finding fishers to interview in 2008 proved to be very difficult as low water levels made boat access almost impossible and therefore there were not many fishers out fishing. I therefore discarded any data from the 2008 interviews and conducted the interviews in This had the advantage of the interview data being gathered in the same year that the fishing catch cards and hoop net surveys were undertaken. This was important as the data generated from each of these three methods was compared in Chapter 4. The interview process was well received by fishers and they openly talked about the topics related to Murray crayfish and the associated fishing regulations. As with the interviews, I initially undertook the fishing catch card surveys in However, I ended up discarding these data and re-distributing the catch cards in 2009 due to few fishers out fishing and so that data would be comparable with interviews and hoop net data. The catch cards worked well, and fishers commented that they were easy to use and fill out. The only problem associated with the use of catch cards is that the accuracy of the catch could be questioned. As I was not present when fishers were filling out catch 207

230 cards, I could not guarantee that the numbers of Murray crayfish were correctly recorded or that measurements were accurate. However, unless I was to accompany each fisher out on his crayfish fishing trip, there was no alternative. Further, this is the main fisher catch data generating method used in commercial fisheries. The use of hoop net surveys to catch Murray crayfish proved very difficult at times due to high river flows, low river flows, submerged branches, difficult weather conditions (strong winds and rain), water temperatures too hot or cold for Murray crayfish, long sampling periods, and the need to find field assistance. For example, during 2008, very low water levels made boat access to river sites almost impossible. During the 1,250 km River Murray hoop net surveys, I initially began sampling in June However, after ten days of intensive sampling, I had captured very low numbers of Murray crayfish and recorded higher than average water temperatures. Thus, I had to start the sampling process again in July 2010 when water temperatures had dropped to their lowest for the year and Murray crayfish were more active. These types of conditions are very difficult to predict, and a trial and error approach seems to be most effective at producing the most accurate outcomes. The experiments that I conducted to determine the effects of handling stress on Murray crayfish egg dislodgement worked well. However, after reflecting on the results, I would have liked to place the females under more extreme conditions to determine if they lost a greater number of eggs when handled the way fishers would handle them (fishers generally throw them in the boat and leave them there until they have finished picking up the hoop nets or until they have finished the days fishing (fishers pers. comm.). The effect of leaving eggs and juveniles that are attached to the mother out of the water for extended time periods has not been investigated. During these experiments I could have determined what the mortality rate of eggs and juveniles was at different durations of being left out of the water. This, however, would have been stressful for both the adult crayfish and eggs or juveniles. 9.4 Management and policy implications Through this research I have considered the management and policy implications of my findings for the Murray crayfish recreational fishery. From the local information I gathered, it was clear that the majority of recreational fishers interviewed did not perceive the Murray crayfish fishery to be sustainable. Fishers wanted to see a number of changes to the 208

231 management of the Murray crayfish fishery in order for sustainability of the species to be protected. The main change suggested was the implementation of a total ban on fishing for Murray crayfish in NSW for three to five years. Other suggested changes included an increase in the number of fisheries inspectors patrolling the rivers, and thus compliance rates; an increase in community education; an increase in communication between fishers, inspectors, managers, and scientists; and an increase in the use of information from fishers in management. Although the reliability of fisher LEK is often questioned, the consistency of the three data generating methods (fisher interviews, fishing catch cards, and Murray crayfish field surveys) indicates that recreational fisher LEK could be a reliable data source that could detect population changes at an early stage and enable proactive and efficient management. The biological information collected through this research produced strong evidence for a need to review a number of fishing regulations. The MLL, which sets the smallest legal length that a particular species can be retained if caught, should be increased to allow a greater proportion of females to reproduce at least once. The current MLL is set at 90 mm OCL. The SOM in this research revealed that at the current MLL, only 39% of female Murray crayfish had reached sexual maturity. My logistic model showed that the size class in which 50% of female Murray crayfish were sexually mature was 91.8 mm OCL. From the model it is also clear that at 100 and 110 mm OCL, 88 and 98% of females were sexually mature, respectively. These findings suggest the MLL should be increased and tailored to specific management objectives relating to the appropriate percentage of sexually mature female Murray crayfish required for a sustainable Murray crayfish fishery. The findings also suggest that commencement of the open season should be moved to a later date to allow the majority of females to come into berry prior to fishing activity. The open fishing season for Murray crayfish in NSW is from 1 May to 31 August each year. This coincides with the onset of the breeding season (mid May) and when females are in berry (mid May November). Thus, under current fishing regulations, females that were not yet in berry could be legally taken at the commencement of the fishing season. If one of the aims of the restricted open season is to allow females to reproduce undisturbed, the 209

232 open season should not commence until a significant proportion of all females have had an opportunity to mate and come into berry. Although berried females must legally be returned to the water, they can be caught, handled, and checked for eggs throughout the open fishing season. The effect of handling on egg and juvenile long-term survivorship is unknown. In my experiments, handling berried females resulted in egg losses in the short-term on almost all occurrences. This should be taken into account when fishing regulations about the timing of the open season are being re-evaluated. Further, the implementation of an education program for fishers that included best handling techniques could limit the stress for berried females and their attached eggs or juveniles. At the time of writing, fishing for Murray crayfish was closed for five years in Blowering Reservoir. This closure was due for review in The low numbers of Murray crayfish, poor size frequency distributions, and a lack of berried females and juveniles captured in Blowering Reservoir, especially when compared to the non-fished Talbingo Reservoir, suggests that re-opening Blowering Reservoir to fishing for crayfish would not be an effective management strategy if the management aims are to achieve a sustainable population of Murray crayfish in Blowering Reservoir. 9.5 Further research Recreational fishers did not perceive that there were effective methods in place to engage or educate the community on Murray crayfish and their associated fishing regulations. Research on the most appropriate methods, both economically and effectively, to best engage and educate fishers would provide management direction for this current issue. The need for a community education program was also highlighted as a key management requirement by Gilligan et al. (2007). There is a need for a basin-wide survey to determine the current status of Murray crayfish across their range. This was suggested as a high research priority by Gilligan et al. (2007). This type of survey would provide a one-off snapshot look at the current distribution of Murray crayfish. However, repeating this survey every two to five years to build up a data base would incur considerable costs. Repeating the Murray crayfish 2009 temporal hoop 210

233 net surveys (three sites sampled monthly over a year period) or the 2010 spatial surveys (1,250 km river reach sampled once in July) every two to five years would provide a longterm detailed data set of population characteristics of Murray crayfish. This would also provide detailed data that could be used to design a population model for Murray crayfish to assist in determining sustainable levels of recreational fishing. Indeed, Gilligan et al. (2007) highlighted the need for an ongoing monitoring program for Murray crayfish. The initial sampling data produced through this PhD would be a good benchmark that could be expanded upon. Ongoing monitoring is also recommended to be continued in Blowering and Talbingo reservoirs. Healthy population distribution and abundance data were recorded in Talbingo Reservoir which had not been previously fished. However, in Blowering Reservoir, which had been open to fishing, Murray crayfish numbers and size frequency distributions were poor. Although Blowering Reservoir is currently closed to fishing for Murray crayfish for five years, this ban is set to be reviewed in The low abundance and lack of berried females and juveniles in Blowering Reservoir justify the need for ongoing monitoring and assessment of that reservoir prior to opening it to fishing. In this thesis I examined the short-term (< five minutes) effects of handling on egg dislodgement in Murray crayfish. Further experiments could be undertaken to identify the effects of handling and keeping the specimens out of water on long-term egg retention and recruitment success. This could be repeated for different time durations of handling and keeping the Murray crayfish with attached eggs or just their eggs out of water. Such information would provide more detail about the variety of outcomes that fisher handling can have on Murray crayfish eggs. The majority of juveniles sampled during this research were caught in Talbingo Reservoir. No juveniles < 40 mm OCL were caught in Blowering Reservoir and very few juveniles were sampled in the River Murray. Previous surveys have also largely failed to sample juvenile Murray crayfish in River systems. Further information is required about the biology and habitats of juvenile crayfish. 211

234 9.6 Summary of key points From the research reported here it is evident that fishing regulations and management need to take both local and biological contributions into account to improve the sustainability of Murray crayfish in NSW. Figure 28 provides a summary of the key points obtained from fisher LEK, biological surveys, and experiments, and illustrates the associations between the methods and the application of this information to increase the sustainability of the Murray crayfish recreational fishery. The key information from fisher LEK and the biological surveys and experiments, together with key directions for changes to management and fishing regulations based on this information and a need for a long-term monitoring program and ongoing review of regulations should be implemented to increase the sustainability of Murray crayfish. Although the specific changes to regulations and management are related to Murray crayfish, these recommendations can be extended to be used for any native species requiring a review of their sustainability. In this research I have provided a review of current fishing regulations and information to change fishing regulations to better reflect crayfish biology and the impacts of fishing pressure. The review of the appropriateness of current fishing regulations should be an ongoing task. Through this work, my aim was to contribute new knowledge to assist a shift towards a more sustainable fishery. 212

235 Fisher interviews Fishing catch cards Hoop net surveys Fisher LEK + Skew in MC size and sex ratios Biological Data MC fishery perceived as not sustainable Changes required to fishing regulations and management to MC fishery sustainability Perceived skew in MC size and sex ratios Perceived in MC abundance and distribution Skew in MC size and sex ratios in fished waters MC abundance higher in non-fished waters MC first berried mid May SOM 50 = 91.9 mm OCL MC eggs dislodged during handling Temporal methods spatial methods Data from detailed studies extrapolated to broader geographic area + Proposed changes in fishing regulations and management F LEK Regulations F LEK Management BD Regulations BD Management Total fishing closure 2-5 yrs Minimum legal length Net and bag limits Open season later Shorter open season Closed areas to fishing Compliance rates Community education Community engagement Aquaculture stock release Catch and release fishery Minimum legal length Open season later Shorter open season Review protection adequacy of berried females Monitor reservoirs, delay reopening Blowering Reservoir Introduce river monitoring program Temporal methods = spatial Ongoing review of = fishing regulations Sustainability Figure 28. Summary of fisher LEK and biological data and its application to increase the sustainability of the Murray crayfish recreational fishery.