Native Fish Strategy project summary Collation and analysis of Murray- Darling native fish datasets FINAL PROJECT REPORT.

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1 Native Fish Strategy project summary Collation and analysis of Murray- Darling native fish datasets FINAL PROJECT REPORT n May 2008

2 Collation and analysis of Murray-Darling native fish datasets FINAL PROJECT REPORT n May 2008 Sinclair Knight Merz ABN Orrong Road, Armadale 3143 PO Box 2500 Malvern VIC 3144 Australia Tel: Fax: Web: COPYRIGHT: This work is copyright Murray-Darling Basin Commission. Graphical and textual information in the work (with the exception of photographs and the MDBC logo) may be stored, retrieved and reproduced in whole or in part, provided the information is not sold or used for commercial benefit and its source (Murray-Darling Basin Commission, Collation and analysis of Murray-Darling native fish datasets, Final project report) is acknowledged. Such reproduction includes fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act Reproduction for other purposes is prohibited without prior permission of the Murray-Darling Basin Commission or the individual photographers and artists with whom copyright applies. To the extent permitted by law, the copyright holders (including its employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or in whole) and any information or material contained in it. The contents of this publication do not purport to represent the position of the Murray-Darling Basin Commission. They are presented to inform discussion for improved management of the Basin s natural resources.

3 Contents 1. Introduction 4 2. Data collation, preliminary analysis and project approach Data collation and review Data sources and licensing Data quality Preliminary statistical analysis Adopted approach 8 3. Native and alien fish of the basin Anecdotes and observations of fish abundance and distribution around the time of European exploration and settlement Aboriginal fisheries of the Murray-Darling Basin Early explorers Summary The rise and fall of commercial fishing Overview Trends in commercial fish harvest Summary Regional trends in fish abundance and distribution The Murray Region Upper Murray (Murray River and tributaries above Lake Hume) Mid Murray (Lake Hume to Darling River Junction) Lower Murray (Darling River Junction to Murray mouth) Victorian tributaries (Kiewa, Ovens, Broken, Goulburn, Campaspe, Loddon, Avoca) Murrumbidgee Region Murrumbidgee River Basin Lachlan River Basin Darling Region Darling River Basin Northern NSW tributaries (Macquarie, Castlereagh, Namoi, Gwydir basins) Border Rivers basin Queensland tributaries (Paroo, Warrago, Condamine basins) Trends in species distribution across the Murray-Darling Basin Basin wide summary of native fish status Current status 105 Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 2

4 8.2 Key drivers of change Conclusions and recommendations Conclusions Recommendations for further investigations Investigation in to the carrying capacity of streams Investigation of recovery and recolonisation ability of native compared to alien fish species References 114 Appendix A Agency databases 119 Appendix B Other data sources 121 Appendix C Workshop attendees 126 Appendix D Distribution map for selected species 127 D.1 Murray Hardyhead 127 D.2 Mountain galaxias 128 D.3 Trout cod 129 D.4 Macquarie perch 130 D.5 Southern pygmy perch 131 D.6 Flat-headed gudgeon 132 D.7 Freshwater catfish 133 D.8 Carp 134 D.9 Eastern gambusia 135 Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 3

5 1. Introduction There is a general consensus amongst the scientific community that fish abundance has declined across the Murray Darling Basin (MDB) and that the distribution of some species has significantly contracted to the point that several species in the Basin are now considered threatened or even locally extinct (MDBC 2003). Recent publicity regarding the condition of streams in the MDB and the need for the provision of environmental flows has focused community attention on aquatic ecosystems, although there is still some dispute regarding the degree of environmental impacts over the past 200 years. Adding fuel to the current debate is potential for the dissemination of misinformation or misinterpretation of various data. Thus, there is a need, from a number of quarters, (including the community, managers and scientists), for sound scientific data to inform and underpin Murray Darling Basin Commission (MDBC) strategies such as the Living Murray Initiative and Native Fish Strategy, various state agencies programs and research and community needs. While we have a general knowledge of the status native fish in the MDB, there is the need to further enhance this knowledge and gain a more detailed understanding of the changes in fish abundance and distribution. The MDBC s Sustainable Rivers Audit will be the first Basin wide program for identifying fish distribution and abundance that uses a consistent approach to fish surveying. However, there have been no historical surveys that have used a common approach across the MDB. Existing databases are often compiled from data collected from a range of techniques and for different purposes. This makes classical analytical techniques difficult because of the inconsistent approach. This project aims to collate all fish survey information from around the MDB and to provide a basin scale overview of the status of native fish in the MDB and trends in abundance and distribution. The project has been undertaken in three phases: 1) assemble available datasets and metadata; 2) analyse data for common trends at Basin, State, and catchment scales as permitted by data quality; and 3) report trends at appropriate spatial scales to relevant stakeholder groups. This document reports represents the final report for this project. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 4

6 2. Data collation, preliminary analysis and project approach 2.1 Data collation and review Data sources and licensing A range of data sources were identified and accessed throughout the project. Data were obtained from State agency and museum databases, institutional databases, hardcopy technical reports, scientific literature and personal datasets. Appendix A summarises agency datasets used to compile the project database. Appendix B lists other data sources reviewed and included in the project database if that data was not already present in agency databases. Despite repeated requests to some data custodians not all data was been provided in a timely manner to be included in the current project. A summary of data known to be missing has been provided separately to the Murray-Darling Basin Commission. There were a number of issues associated with accessing data. Typically, agencies were reluctant to provide raw data that had not been checked through internal quality and data control processes. This meant that in many instances data that were provided does not represent the most recent survey data because some agency databases are several years behind in being updated. In addition, some agencies do not have dedicated databases or there were third party confidentiality or data licensing issues that prevent access to some relevant data fields (e.g. specific locations or effort data). Also, there are significant amounts of unprocessed data held by individuals in disparate locations or in technical reports that often do not contain relevant fields that enable specific locations or abundance to be determined. Data supplied from state agencies and museums are all subject to data licensing agreements that govern the future use of this data. Data has been supplied for sole use in the current project and a concurrent project mapping fish distribution. The granting of data licence agreements for the current projects does not guarantee that data will be made available for future projects. If the Murray-Darling Basin Commission wishes to use this data for future projects then they will need to enter specific negotiations to gain approval from respective data custodians and indeed may need to request data again rather than rely on that collated for the current project. The negotiating and granting of data licence agreements imposed a significant time constraint on the current projects and caused undue project delays. It is strongly recommended that the Commission establish data license agreements well in advance of the contracting of any future projects that may wish to use this data. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 5

7 2.1.2 Data quality A lot of the data that was provided was of poor quality with obvious errors in location and species names. For example, some species were listed under different common names and multiple species were grouped under a single genera (e.g. galaxias sp.) or family (e.g. cods and basses). For the most part, groupings represent very few records (e.g. the grouping freshwater perches comprises less than 10 records, compared with greater than 1000 records for each individual perch species). Under these circumstances the removal of a few records of dubious quality has no observable impact on analysis and improves the confidence in the analysis. There were also a number of duplicate entries. Duplicates have been identified by cross referencing location and sample date. These errors have been corrected as best as possible, however, the volume of data meant that not every single record was individually checked for accuracy. Data base records often omitted information on effort and what effort data is available is restricted to the last years, hence it is of limited value in assessing historical trends because there is no effort data associated with early surveys with which to compare. In addition, where effort information was provided it was unclear as to what units the effort was in. For example, electrofishing effort could be recorded as total fishing time, machine on time (sometimes in seconds and sometime in minutes) or length of river fished with no time unit provided. In addition, it was not always clear whether multiple passes had been conducted and whether effort data accounted for this. With respect to netting methods, soak times were occasionally provided, although in some instances multiple nets were set but the total number of nets set was not provided and it is unclear whether soak times are for a single net or cumulative for all nets. Further, some records were for individual species caught in each survey (i.e. there are multiple records for a single species at the one location and sampling time) while within the same database there are other survey records where the total number of each species captured is recorded. Where possible, we interrogated the data to identify where individual species were recorded and then summed the totals to provide a total count of each species for each survey. For some survey records the number of individuals captured was not recorded at all. 2.2 Preliminary statistical analysis Based on the data collected a range of statistical analyses have been considered and explored. Results of statistical reviews and preliminary analysis were presented at two workshops attended by members of the project steering committee, data custodians, fisheries agency personnel and researchers to discuss and confirm the final approach to analysis (see Appendix C for details of attendees). A key objective of this project was to assess historical trends in native fish abundance across the basin. In consultation with Associate Professor Ian Gordon from the Melbourne University Statistical Consulting Centre we explored the applicability of a range of techniques for assessing Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 6

8 trends in abundance. The ability of these approaches to provide an accurate assessment of trends is governed by the availability of suitable data. The potential techniques were presented at the two workshops. These techniques can be used to identify trends in absolute or relative species abundance and density over time but have some specific data requirements; namely, temporal replication at the site, or at least basin or zone scale, and effort data. For an accurate assessment of trends effort data across a relevant time frame is required to standardise the analysis. Typically a minimum of ten years of data is required, although the method is robust enough to deal with some zeros (i.e. where sampling occurred but a specific species was not recorded) or where data is missing (i.e. no sampling in a year occurred). Unfortunately, within the data received there was limited data on catch effort and as describe earlier the quality of the effort data is poor. On the basis of this we have not assessed trends using standardised effort data. Another technique examined included ranked abundance as an option for assessing changes in abundance over time. Rank abundance was calculated by pooling all survey data in ten year periods and determining the species rank on the basis of total records. Ranked abundance was determined for each basin. The results indicated some preliminary patterns. For example, in the mid 1900s carp was absent from survey records but from 1970 onwards the rank abundance of carp increased to be near the highest ranked species in most southern basins and the ranked abundance of silver perch decreased over the last 50 years. In northern basins native fish such as bony herring and golden perch remain relatively highly ranked. However, there are some significant problems with the ranked abundance approach. Ranking does not consider the absolute number of fish captured. Ranking can be misleading, for example, in basins or time points with few species the lowest ranked species can appear highly ranked when compared against basins or time points with many species. There are also biases in methods used with different methods targeting different species and improved efficiencies in capturing fish over time. Hence it was concluded not to use rank abundance as an approach. Analytical methods that we believe are appropriate are ones that can be undertaken independent of effort but stratified for method and are aimed at showing general patterns in the survey data, providing information on species richness and diversity, analysis of percentage of sites where each species has been captured and analysis of relative proportions of native versus alien species. Where possible, some of these measures can be assessed over time if sufficient temporal data is available. A number of conclusions were drawn from the review of available data: n Data was of variable quality, often with missing fields and obvious errors. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 7

9 n n n There is limited effort data to enable standardised assessment of trends in abundance over historical time scales. When stratified for method there is limited temporal scale over which trends can be assessed (only last years). Trends in relative abundance can be assessed over recent years for some specific locations, but the majority of historical change has likely occurred before bulk of surveys so it is difficult to make conclusions based on this type of assessment 2.3 Adopted approach From the data collated most quantitative data is only available for the past years and what is available is patchily distributed across the basin. While this analysis indicates some trends in recent years it doesn t provide an indication of longer term trends in historical abundance. As discussed in subsequent sections, anecdotal evidence from early explorers (e.g. Scott 2005), historical investigations (e.g. Cadwallader 1977, Mallen-Cooper and Brand 2007) and analysis of commercial catch data (e.g. Reid et al. 1997) it would seem that the majority of decline in native fish abundance occurred in the late 19 th and early to mid 20 th centuries. Hence patterns observed over the last years are likely to represent relatively small changes in abundance compared to the longer term historical decline in abundance that has occurred in some basins. As such, our approach has been to document historical trends based on available literature and anecdotal information and where possible augment this qualitative assessment with specific examples where some quantitative data is available, though such examples are limited to only a few locations over the entire basin (for example Mallen-Cooper and Brand 2007). Even though the data collected is of limited value for assessing abundance it provides a significant volume of data on fish location and collection date (Figure 2-1). Hence, it has been possible to plot maps of recorded locations at various time intervals to show basin scale spatial and temporal changes in distribution of key species; although some caution is needed in the interpretation of changes in distribution for various species as a lack of records doesn t mean that a particular species is not present. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 8

10 n Figure 2-1 Distribution of fish record sites across the MDB collated for the current project Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 9

11 3. Native and alien fish of the basin At latest count 47 native species have been recorded from the Murray Darling Basin (Table 3.1 and see Lintermans (2007)). Several of these species are part of larger species complexes (e.g. carp gudgeons), are new species based on recent genetic analysis (e.g. mountain galaxias are likely to be separated into three species), or have been recorded for the first time in recent years due to increased survey effort (e.g. desert rainbowfish, Rendahl s tandan and Yarra pygmy perch) (Lintermans 2007). In addition, a number of species are considered to have been translocated from coastal catchments directly via human assistance (e.g. common galaxias), via inter-basin pipeline transfer (e.g. climbing galaxias and spotted galaxias) or via occasional overland migration (e.g. long finned eel). Of the native species present in the Basin 18 have some form of conservation status at either State or National level. A number of species may have restricted distributions in some states but have not been assigned a formal conservation status. Eleven alien species have been recorded in the Basin (Table 3.2). n Table 3.1 Native fish species of the Murray-Darling Basin and their current conservation status. Family Scientific Name Common Name Habitat Conservation Status Nat. a Qld b NSW c ACT d SA e VIC f Ambassidae Ambassis agassizii Olive perchlet F EPop Prot Ex (L) Anguillidae Anguilla australis Short-finned eel E Anguilla reinhardtii Long-finned eel E / T Atherinosoma microstoma Small-mouthed hardyhead E Atherinidae Craterocephalus amniculus Darling River hardyhead F Craterocephalus fluviatilis Murray hardyhead F V E E (L) Craterocephalus stercusmuscarum fulvus Un-specked hardyhead F L Bovichthyidae Pseudaphritis urvilli Tupong/Congolli E Clupeidae Nematalosa erebi Bony herring F Hypseleotris klunzingeri Western carp gudgeon F Hypseleotris sp. Midgley s carp gudgeon F Eleotridae Hypseleotris sp. Lakes carp gudgeon F Hypseleotris sp. Murray-Darling carp gudgeon F Mogurnda adspersa Southern purple-spotted gudgeon F EPop Prot CE (L) Philypnodon grandiceps Flat-headed gudgeon F Philypnodon macrostomus Dwarf flat-headed gudgeon F Gadopsidae Gadopsis bispinosus Two-spined blackfish F V Gadopsis marmoratus River blackfish F Prot Galaxias brevipinnis Climbing galaxias F / T Galaxias fuscus Barred galaxias F E CE (L) Galaxias maculatus Common galaxias E / T Galaxiidae Galaxias olidus Mountain galaxias F DD Galaxias sp. 1 Obscure galaxias F Galaxias sp. 2 Riffle galaxias F Galaxias rostratus Flat-headed galaxias F DD Galaxias truttaceous Spotted galaxias F / T Geotriidae Geotria australis Pouched lamprey E Afurcagobius tamarennsis Tamar goby E Gobiidae Pseudogobius olorun Western blue-spot goby E Tasmanagobius lasti Tamar goby E Melanotaeniidae Melanotaenia fluviatilis Murray-Darling rainbowfish F DD (L) Melanotaenia splendida tatei Desert rainbowfish F Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 10

12 Mordaciidae Mordacia mordax Short-headed lamprey E Nannopercidae Nannoperca australis Southern pygmy perch F V Prot Nannoperca obscura Yarra pygmy perch F V Prot LR (L) Maccullochella Trout cod/bluenose cod F E E E Prot CE (L) macquariensis Maccullochella peelii peelii Murray cod F V V (L) Percichthyidae Macquaria ambigua Golden perch F V Macquaria australasica Macquarie perch F E V E E (L) Macquaria colonorum Estuary perch E Neosilurus hyrtlii Hyrtl's tandan F Plotosidae Porochilus rendahli Rendahl s tandan F Tandanus tandanus Freshwater catfish F Prot V Retropinnidae Retropinna semoni Australian smelt F Terapontidae Bidyanus bidyanus Silver perch F V E Prot CE Leiopotherapon unicolor Spangled perch F Habitat: F-Freshwater reaches, E-Predominantly estuary reaches, T-Translocated from coastal catchment Conservation status: a EPBC, Listed under the Commonwealth Environment Protection and Biodiversity Conservation Act I999 b QLD, No Basin fish are listed under the Fisheries Act 1994 although the river blackfish is classified as a no take species c NSW, Listed under the Fisheries Management Act 1994 d ACT, Listed under the Nature Conservation Act 1980 e SA, protected under the Fisheries Act 1982 f VIC, Conservation status under 2003 advisory listing, (L) Flora and Fauna Guarantee Act 1988 (FFG) listed. Ex extinct, CE critically endangered, E endangered, EPop endangered population, V vulnerable, LR lower risk near threatened, DD data deficient, Prot - protected in SA n Table 3.2 Alien fish species of the Murray-Darling Basin. Family Scientific name Common name Cobitidae Misgurnis anguillicaudatus Weather loach Carassius auratus Goldfish Cyprinidae Cyprinus carpio Carp Rutilus rutilus Roach Tinca tinca Tench Percidae Perca fluviatilis Redfin perch Poeciliidae Gambusis affnis Eastern gambusia Oncorhynchus mykiss Rainbow trout Salmonidae Salmo salar Atlantic salmon Salmo trutta Brown trout Salvelinus fontinalis Brook char The following sections provide a more detailed discussion of changes in fish abundance at the subbasin scale (Figure 3-1). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 11

13 n Figure 3-1 Sub-basins of the Murray-Darling Basin Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 12

14 4. Anecdotes and observations of fish abundance and distribution around the time of European exploration and settlement 4.1 Aboriginal fisheries of the Murray-Darling Basin Native fish provided a bountiful resource for Aborigines throughout the Murray-Darling Basin as referenced in reports, for example from early explorers, naturalist and settlers (Humphries 2007), and also in longer historical records based on analysis of middens (Balme 1995). The Aboriginals were adept at catching large quantities of fish using a variety of techniques and so important was fish as a source of food that it is suggested they may have actively managed rivers to sustain fish stocks (Humphries 2007). Aborigines constructed walls of branches and grass across creeks and rivers, they then herded fish into these walls where they were caught or speared (Dargin 1976). Walls and weirs were also erected as a fresh was coming down to catch and hold fish moving downstream. Larger, more substantial weirs were used to pond water, holding fish for longer periods of time than would have otherwise occurred, thus maintaining a ready supply. There is some suggestion that the conservation of fish in streams depended on the placement of these weirs by Aborigines; who also collected small fish and released them behind barriers they had constructed on the smaller tributary streams. Thereby conserving nursery areas and providing small pools of fish from which recolonisation could occur. The Aborigines also fished rivers with nets, some of which could be strung across 90 meters of river channel, and permanent traps. Mitchell mused that at one time on the Barwon River No fish could be caught this day, and we supposed that the natives were busy taking them, above and below our camp, for, in their mode of fishing, few can escape (Mitchell (undated) quoted in Dargin 1976). The most substantial fish traps were located on the Darling River at Brewarrina in northern NSW. The traps were built from stones, which were formed into intricate walls with openings leading to blind ends. Fish were most often trapped during spring when they migrated upstream in large numbers, although fish moving downstream, perhaps to escape poor water quality, could also be trapped by rearranging the openings (Dargin 1976). Thousands of Aboriginals where thought to congregate around the fish traps at certain times of the year. The traps were so effective at catching fish and the fish so plentiful that Drayloads of fish are thus taken, and a season of festivity or gluttony supervenes [extract from the South Australian Register, 11/5/1859 cited in Dargin (1976)]. In the mid 1860s desnagging along the Darling River took place to improve passage for paddle steamers. The Aboriginal stone fisheries at Brewarrina, and elsewhere along the Darling River, were also partly dismantled or totally removed to facilitate passage. However, it was also noted Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 13

15 that in some locations trees were deliberately felled across the river, perhaps in an attempt to impede navigation and conserve the fisheries (Dargin 1976). Aboriginal interest in the Brewarrina fish traps waned from 1889 onwards and by 1915 only one man consistently worked the remaining traps. In the 1920s large quantities of stone were removed from the traps to be used as building material for houses and roads in the district (Dargin 1976). According to Mary Gilmour, who lived as a child in the 1870s on the Murrumbidgee River near Wagga Wagga, the loss of fish in her local rivers was a direct result of the death and displacement of Aborigines (Humphries 2007). The Aborigines being responsible for maintaining fish sanctuaries, understanding the need for closed seasons on fishing to support breeding and selective capture to maintain stocks. 4.2 Early explorers During the early to mid 19 th century, explorers and pioneering settlers moved west through the Murray Darling system in search of new land to support the growing colony of Sydney. The earliest records made by Europeans of fish within the Murray Darling Basin are found in the diary and journal extracts of these early explorers and have been compiled and summarised by Scott (2005). These early records provide an insight into the general distribution of native fish in the Murray Darling system, prior to large-scale land clearing, river regulation and alien fish invasion. The following descriptions are based on the review of Scott (2005) unless indicated otherwise. The first record of a Murray cod is from 1813 in the Fish River, a tributary of the Macquarie River. George Evans described abundant fish (Murray cod) in the Fish and Macquarie Rivers; he was surprised by the size and quantity of fish, and the ease with which they could be caught. In 1817 and 1818, John Oxley travelled down the Lachlan and Macquarie Rivers respectively. In the Lachlan River he described catching..nearly a hundred weight of fine fish in one evening, and on one occasion his men caught a 70 lb (30 kg) cod, along with many others ranging in weight from lbs, although most fish caught during the expeditions appeared less than 10 lbs. In the Macquarie River in 1818, Oxley described catching a new species of fish (a catfish). On other occasions, fishing was poor and was attributed to floods and cold weather. In 1824, Hamilton Hume and William Hovell, on a journey from Sydney to the southern coast, were the first Europeans to encounter the Murray River near Albury and named it the Hume River (later renamed the Murray River by Charles Sturt). During this journey they also crossed the Murrumbidgee, Tumut, Mitta Mitta, Kiewa, Ovens and Goulburn Rivers. They reported an abundance of fish and regularly caught Lachlan codfish (Murray cod) in most rivers crossed along the way. They also caught bream or carp (possibly a silver, golden of Macquarie perch), in lagoons adjacent the upper Murray River and the Kiewa River. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 14

16 In 1827 Allan Cunningham journeyed from the Hunter Valley to the Darling Downs in south east Queensland. Along the way he crossed the Peel, Namoi, Gwydir Macintyre, Dumaresque and Condamine Rivers and tributaries, including the Severn River, and reported easily catching cod of all the western rivers (Murray cod). Some of the more significant journeys in to the Murray-Darling Basin interior were those of Charles Sturt in 1828 and In 1828 he journeyed down the Macquarie River to the Darling River. Along the way he encountered the Barwon, Bogan and Castlereagh Rivers and commented on the abundance of fish, including cod and bream. Of the Darling River, Sturt pondered how such a river could sustain the great abundance of fish observed, unless it..owed such abundance, which the pelicans seemed to indicate was constant, to some Mediterranean sea or other. Even more extensive where the four journeys of Thomas Mitchell between 1831 and Mitchell, in his first journey, travelled north west from Sydney through the Peel, Namoi and Gwydir catchments to reach the Barwon River near the Queensland border. His party caught codfish (Murray cod) in the all four rivers, and catfish and silver perch in the Namoi and Barwon River; the fish in the Barwon River being particularly abundant. Mitchell s second journey took him down the Bogan River to the Darling River, and then down the Darling to just upstream of Menindee. During this journey the Bogan River was dry, but the Darling River flowed. The most abundant fish in the Darling River were Murray cod and silver perch. At Bourke Mitchell described the Darling River thus,.. the water being beautifully transparent, in the bottom was visible at great depths, showing large fish in shoals, floating like birds in mid-air. He also described a small lake (probably a billabong) as being full of fish. In his third, and most extensive journey, Mitchell travelled down the Lachlan to the Murrumbidgee and then on to the Murray River. He then travelled up the Murray River to near Kerang before turning south west and heading to the south west coast of Victoria; along the way traversing the Loddon, Wimmera and Glenelg catchments. From the coast he headed back to Sydney crossing the Campaspe, Goulburn, Broken, Ovens, Murray and Murrumbidgee Rivers. Along the way he described catching Murray cod, silver perch and catfish. He also noted the use by Aboriginals of eucalyptus boughs to poison fish in deep waterholes and trapping techniques used in anabranches. Mitchell s fourth journey from December 1845 to December 1846 saw him travel down the Bogan River, east to the Macquarie and then north in to Central Queensland, on the way crossing the Barwon-Darling near the junction with the Castlereagh, and also the Narran, Balonne and Maranoa Rivers. He described catching large Murray cod in the Balonne and Maranoa Rivers, catfish in the Maranoa River and several other species not previously encountered in the more southern parts of the Basin, including one described as a Harlequin fish. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 15

17 In the 1830s, George Bennett explored the Yass, Murrumbidgee and Tumut regions. He reported large quantities of river cod, possibly both Murray and trout cod; one Murray cod weighed 120 lbs. It was not until 1858 when a clear distinction between Murray cod and trout cod was provided by Blandowski (cited in Trueman 2007) based on descriptions and illustrations of the differences between Murray cod and trout cod captured in the Murray River between Gunbower and the Darling junction. Early settlers in the southern Murray-Darling Basin also described the large quantities of fish present in the rivers, particularly Murray cod (Scott 2005). 4.3 Summary In summary, in the early to mid 1800s, around the time the first Europeans were exploring the Murray-Darling Basin, native fish, namely Murray cod, silver perch and freshwater catfish, appeared widely distributed and abundant, the former being extremely abundant in some areas. Aborigines were adept at catching fish using a variety of techniques, and at times fish were so plentiful that sufficient fish were available to feed hundreds or even thousands of people during seasonal gatherings along the Darling River, and presumably elsewhere in the Basin. The Aboriginals also manipulated river systems through the construction of weirs and the transfer of fish from one location to another, apparently to conserve fish stocks during dry periods when many inland rivers ceased to flow. Evidence regarding the distribution and abundance of native fish around the time of European exploration and settlement is limited to descriptions of large bodied fish, presumably because of their food value. There is scant information on the types, abundance or distribution of small bodied native fish. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 16

18 5. The rise and fall of commercial fishing 5.1 Overview From the mid 1800s commercial fishing was established in the larger waterways of the basin. In South Australia commercial fishing commenced in the Lower Lakes and Coorong region in the late 1840s but expanded rapidly throughout the lower River Murray in the early 1850s with the advent of the paddle steamer trade (Sloan 2005). The Lower Lakes and Coorong Fishery was dominated by estuarine species but the construction of the lower Murray barrages in the 1940s, resulted in an increase in freshwater habitat in Lakes Alexandrina and Albert and a consequent increase in the number of freshwater species targeted, especially golden perch (Sloan 2005). Murray cod were the focus of the River Fishery. The South Australian River Fishery was closed in 2001, but the Lower Lakes and Coorong Fishery remained open (Sloan 2005). In New South Wales commercial fishing of native species, primarily based on Murray cod, commenced in the Murray River near Echuca in 1859 (Humphries 2007) and rapidly expanded along the Murray, Edwards, Wakool, Murrumbidgee and Darling Rivers. Commercial fishers also operated on some northern rivers (e.g. the Paroo, Warrego, Culgoa and Narran Rivers), but long periods of low or no flows restricted efforts and meant they were only fished infrequently (Reid et al. 1997). Commercial fishing for native species ceased in NSW in 2001 but a restricted fishery for carp and yabbies continues (NSW Department of Primary Industries 2006). In Victoria commercial fishing was limited to anabranches of the Murray River, the lower reaches of larger rivers such as the Loddon and Goulburn Rivers and some floodplain lakes (Cadwallader 1977). All commercial licences for harvesting native fish (except eels) in Victoria were bought back in Scant information is available on commercial inland fishing in Queensland but it is likely to have been limited and would have suffered similar issues to that experienced in northern New South Wales. Fish were initially supplied to local towns and the developing goldfields, but by 1883 were also supplied in considerable quantities to markets in Melbourne, Adelaide and Sydney (Rowland 1989, Humphries 2007). Murray cod accounted for the vast majority of native freshwater fish supplied to markets; in 1900, 75% of river fish sold at the Melbourne market were Murray cod, the remainder being golden perch (Poole 1984 cited in Rowland 1989). Techniques used by commercial fishers included drum nets, bag nets and gill nets. Nets often stretched for several hundred meters, from bank to bank and overlapped with other nets and were indiscriminate in their effectiveness; capturing virtually all fish, regardless of size and age and ignoring spawning times and nursery habitats (e.g. Moira Lakes) (Humphries 2007). Within only a few years of the establishment of commercial fishing concerns were being expressed about the impact on native fish, including calls for a closed season on fishing (The Argus, 3 November Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 17

19 1873), and a Royal Commission on Fisheries was conducted in NSW that expressed concerns about the sustainability of fish stocks and lack of effective fishing regulations (Humphries 2007). Humphries (2007) argues that in only a few decades the rivers went from supplying Aboriginal people with a bountiful food source to one which was severely depleted. 5.2 Trends in commercial fish harvest Data records kept by commercial fisherman and reported by various authorities are of variable quality but nonetheless provide some insights into the status of fish stocks and provide evidence of significant changes in fish stocks over time. Unfortunately there is little data available to accurately document native fish stocks in the late nineteenth and early twentieth centuries. However, some data available at the time suggested that between 1883 and 1933, despite large fluctuation in native fish populations from year to year, there was a decline in the overall commercial fish catch. The catch peaked in 1918 but by the mid 1930s the commercial fishery had declined to a level considered unprofitable for large-scale operators (Rowland 1989). Figure 5-1 shows the total weight of fish consigned from Victorian and New South Railway stations from 1883 to 1933 and for selected individual stations on the Murray, Murrumbidgee and Darling Rivers. Weight of fish consigned from Victorian and NSW railway stations (kg) Year Total Echuca/Moama Denilequin Mildura Koondrook Swan Hill Brewarrina Bourke Hay n Figure 5-1 Weight of fish consigned from Victorian and New South Wales railway stations from 1883 to Plot shows total consignment weight and weights for selected stations along the Murray, Murrumbidgee and Darling Rivers (data sourced from Reid et al. 1997). Although there is no information available on the type of fish or number of fisherman contributing to the total catch, apart from a very large peak in consignment from Swan Hill in 1934, there appears to be a decline in the catch from 1918 onwards. Rowland (1989) attributes this early Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 18

20 decline to overfishing. This is supported by anecdotes presented in a summary of historical data and management issues gleaned from reports to the NSW Fisheries Department from 1883 to 1954/55 by Reid et al. (1997), some of which are summarised below. In the late 1800s the decline was mostly attributed to overfishing using illegal techniques, such as gill nets stretched across the entire river, which captured all fish: The decrease in the quantity of fish send to Victoria is caused through excess netting activities [1896 NSW Fisheries Department report cited in (Reid et al. 1997)]. Through the early to mid 1900s there were increasing reports of declines in native fish capture and increases in the numbers of alien species, particularly redfin perch: Great number of English perch and carp were netted in shallow waters near Corowa and Albury while indigenous fishes were in negligible quantities. The various English perch is rapidly increasing in numbers in the Murray River and adjacent creeks and is becoming a serious menace to the fishery [1921 NSW Fisheries Department report cited in (Reid et al. 1997)]. Although the introduction of a closed season, the tighter enforcement of regulations and wet years were thought to contribute to occasional increases in fish caught: Very good sport, the best for many years was obtained by amateurs. Murray cod and golden perch were never having been so plentiful [1931 NSW Fisheries Department report cited in (Reid et al. 1997)]. And The productivity of Inland waters have progressively increased during recent years which may be due to good seasons and full rivers [ NSW Fisheries Department report cited in (Reid et al. 1997)]. More substantive data on the state of the commercial fishery in the southern Murray-Darling Basin is available from the mid 1900s onwards and has been analysed and reported in a number of publications (e.g. Cadwallader 1977, Rowland 1989, Reid et al. 1997, Gilligan 2005b, a, Rowland 2005). This data are predominantly from New South Wales, although some more recent data also exists for the South Australian River Fishery (e.g. Ye et al. 2000). The commercial fishery in the late 1800s and early 1900s appeared dominated by Murray cod but from the mid 1900s the native fishery was dominated by golden perch (Figure 5-2). The decline in the availability of Murray cod as a result of overfishing through the late 1800s and early 1900s (Rowland 1989, Reid et al. 1997) probably forced a shift to alternative species such as golden Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 19

21 perch. After a peak in Murray cod harvest in the mid 1950s, total catches declined rapidly and were relatively stable from 1966 onwards with occasional small increases. Rowland (1989) suggested the depressed catch from the 1960s onwards was due to poor larval recruitment. He attributed this to a reduction in the frequency, extent and duration of spring flooding in the Murray River as a result of river regulation arising from the construction of weirs and dams through the early and mid 1900s. This is supported by various anecdotes, initially collected by J.O. Langtry and published in Cadwallader (1977), suggesting that following the construction of Hume Dam (completed in 1936) and Yarrawonga Weir (completed in 1939) the frequency, duration and timing of flooding in the Barmah Forest was reduced, the water clarity decreased and the fishing declined noticeably. There were also significant fish kills in the river and floodplain lakes associated with the first releases of water from Hume Dam, attributed to large amounts of eucalyptus and ash (Cadwallader 1977). There is also a suggestion that an increase in redfin perch abundance coincided with a decline in native fish (Cadwallader 1977) and that this may have also contributed to the decline of Murray cod in the southern parts of the basin (Rowland 1989). Catch (tonnes) Murray cod Golden perch Silver perch Freshwater catfish Carp Redfin perch Total Year n Figure 5-2 Annual NSW commercial fisheries catch for key species 1947/48 to 1995/96 (data sourced from Reid et al. 1997). Despite the decline in the Murray cod harvest the golden perch harvest remained relatively stable and with occasional peaks in 1955, 1975 and Reid et al. (1997) suggest these peaks appear to correlate with times of higher river flows, which may have made catchability easier and promoted improved recruitment. However, Gilligan (2005b, 2005a) found no significant Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 20

22 correlation between commercial catch and discharge in the lower Murray, Darling or Murrumbidgee fisheries and the relationship between flow and fish stocks remains equivocal. For example, commercial catch data from Lindsay River and Walpolla Creek, Victorian anabranches of the Murray River in the Mallee district, shows significant differences in the total annual catch between 1949 and 1950 and also large shifts in the relative contribution of difference species to the total catch (Table 5.1). In Lindsay River the total catch increased over 5 fold from 1949 to 1950, the percentage of golden perch increased from 3.7 to 21.5% by weight of the catch while Murray cod decreased from 64 to 33.5%. Conversely, in Walpolla Creek the catch decreased by ~50% from 1949 to 1950 although there was still an increase in the percentage of golden perch. Also note the relatively large contribution of redfin perch to total catch in Lindsay River, but their absence from the catch in Walpolla Creek. The reasons for such marked year to year variability are unclear but could be related to a shift in effort from one location to another because of changes in antecedent conditions, for example river flows. n Table 5.1 Percentage by weight of annual commercial catch in 1949 and 1950 from Lindsay River and Walpolla Creek (Data source Cadwallader 1977). Species Lindsay River Walpolla Creek Year Golden perch 3.7% 21.8% 39.8% 58.2% Silver perch 4.7% 1.6% 3.5% 0.5% Murray cod 64.0% 33.5% 40.7% 36.5% Freshwater catfish 5.8% 10.3% 1.4% 3.5% Carp 0.4% 14.6% 1.3% Redfin perch perch 21.2% 32.8% Tench 0.02% Total weight (kg) In more recent times a notable characteristic of the commercial catch data is a rapid increase in the catch of carp. Carp were introduced in to the Murray-Darling Basin in the 1940s and 1950s (Koehn et al. 2000) and were reported in small numbers in the commercial catch around that time (Cadwallader 1977, Reid et al. 1997). However a dramatic rise occurred in the early 1970s (Figure 5-2) following the introduction of the Boolara strain in 1968 and large floods in the mid 1970s that helped substantially increase the distribution and abundance of carp (Brumley 1996). From 1977 onwards carp dominated the commercial fish catch. In 2001 the native commercial fishery in NSW was closed, but carp and yabbies are still commercially harvested under the Inland Restricted Fishery (NSW Department of Primary Industries 2006). When assessed by drainage basin, the Murray River drainage made the greatest contribution to the total catch, followed by the Darling River drainage (Figure 5-3). In all basins golden perch and more recently carp have dominated the commercial catch over the past fifty years. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 21

23 Some data are available to enable an assessment of catch effort of commercially important species, however only course assessments are possible. From 1953 onwards information is available on the number of fishers in the industry and from 1984 onwards the number of fisher-days per year were also recorded (Reid et al. 1997). Hence, from 1954 it is possible to calculate the average catch per fisher, and from 1984 onwards the average catch per fisher-day (Figure 5-4). The catch per fisher was relatively stable up to 1984 at around 2000 kg per fisher per year. Since 1984 the catch per fisher increased substantially to a peak of ~11,500 kg per fisher per year. The catch per fisher-day also increased from around 15 kg to 30 kg per fisher-day. Reid et al. (1997) attributed this to an increase in the catch of golden perch in the early 1990s although from an historical context this peak was only a little over half of the peak golden perch catches in 1954 and The increase in catch per fisher-day also coincided with an increase in the carp harvest (Figure 5-2). From the early 1980s there was a rapid decline in the number of fishers from around 250 to less than 100 (Reid et al. 1997), so it is possible that the sharp increase in catch per fisher-day was related to one, fewer fisherman accessing the available pool of fish which would result in an increase in catch per fisherman and two, an increase in the pool of fish available in the late 1980s of both golden perch and carp, perhaps in response to a period of higher flows and improved recruitment. However, the peak harvest of native fish was still lower than previous peaks. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 22

24 Catch (tonnes) Murray cod Golden perch Total NSW commercial catch Freshwater catfish Silver perch Carp Redfin perch Catch (tonnes) Murray cod Murray River drainage commercial catch Golden perch Freshw ater catfish Silver perch Carp Redf in perch Murrumbidgee River drainage commercial catch 250 Lachlan River drainage commercial catch Catch (tonnes) Catch (tonnes) Murray cod Golden perch Freshw ater catfish Silver perch Carp Redf in perch 0 Murray cod Golden perch Freshw ater catfish Silver perch Carp Redf in perch 800 Darling River drainage commercial catch 350 Other drainage commercial catch Catch (tonnes) Catch (tonnes) Murray cod Golden perch Freshw ater catfish Silver perch Carp Redf in perch 0 Murray cod Golden perch Freshw ater catfish Silver perch Carp Redf in perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 23

25 n Figure 5-3 Catch per decade for key species ( ) from New South Wales commercial fisheries (total catch and for key drainages) (data sourced from Reid et al. 1997). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 24

26 n Figure 5-4 Average annual catch per fisher and catch per fisher-day) (1953/ /96) (Reid et al. 1997). Elsewhere, analysis of standardised commercial fishing data has indicated a small recovery in native fish stocks in some locations during the 1990s, for example golden perch and Murray cod in the Lower Murray-Darling catchment (Gilligan 2005a). In South Australia the Murray cod harvest followed a similar pattern to that observed further upstream. The Murray cod catch peaked in the late 1950s at around 150 t per annum and steadily declined from then on to be steady at around 10 t per annum since the mid 1970s (Figure 5-5). A small recovery in the commercial catch of Murray cod in the River and Lakes fisheries in South Australia was reported following a 3-year moratorium on commercial fishing from , which was attributed to a strong recruitment following flooding in 1989 (Ye et al. 2000). However, subsequent data showed a significant decline in catch in 2002/03 (Figure 5-6 and see Knight et al. (2004)) and the overall total catch remained well below that recorded in the 1950s. The River Fishery in South Australia has subsequently been closed, however the Lakes and Coorong Fishery remains open for native species such as golden perch and bony bream, and for alien species such as carp and redfin perch perch (Sloan 2005). There is little long term data on the status of the Lakes and Coorong Fishery. Prior to the installation of the barrages in 1940 the lakes were estuarine. However, since this time freshwater species have dominated. Some data are available from the mid 1980s. These data show that the Lakes Fishery are dominated by bony bream and carp (Figure 5-7). The golden perch harvest peaked around 200 t per annum in the mid 1990s but has more typically been around t per annum. In the early 2000s the total catch declined substantially from its early 1990s peak. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 25

27 However the record is too short to put this in a longer term context, hence it is not possible to comment on historical trends. n Figure 5-5 Total Murray cod commercial landings in the River, Lakes and Coorong fisheries 1951/52 to 1999/2000 (Ye et al. 2002) Total Murray cod (kg) catch in the river Fishery Murray cod (kg/f isher-day) in the River Fishery / / / / / / / / / / / / / / / / / / / / / / / / / / /92 Total catch (kg) 1992/ / / / / / / / / / /03 kg fish per man day n Figure 5-6 Total Murray cod catch and catch per fisher-day in River Fishery 1984/85 to 2002/03 (data source Knight et al. 2004). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 26

28 2500 Redf in 2000 Carp Bony bream Golden Perch / / / /88 Total catch (tonnes) 1988/ / / / / / / / / / / / / / /03 n Figure 5-7 Total catch (freshwater species) in the Lakes and Coorong Fishery 1984/85 to 2002/03 (data source Knight et al. 2004). 5.3 Summary In summary, commercial fishing commenced in the mid 1800s, predominantly focused along the lower Murray, Murrumbidgee and Darling Rivers and targeting Murray cod. Within a few decades concerns regarding the state of the fishery and declines in fish stocks were being voiced, although occasional good harvest years, probably related to wet years, still occurred into the mid and later 1900s. There is limited data to enable a detailed assessment of catch effort. However, data that are available documents a decrease in the total catch of native fish from most fisheries from peaks in the early to mid 1900s. In particular, there was a decline in the harvest of Murray cod and a shift towards an increased harvest of golden perch from the mid 1900s onwards. The harvest of golden perch, while variable from year to year has remained relatively stable, particularly in the Darling River and Lachlan River drainages and possibly in the South Australian sections of the River Murray and the lower Lakes. Carp appeared in the commercial catch in the 1960s and since the mid 1970s has dominated the commercial catch in nearly all areas Overfishing and indiscriminate fishing techniques were blamed for early declines in Murray cod. From the early to mid 1900s onwards river regulation that has reduced the frequency, duration and Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 27

29 magnitude of flood events, and possibly the introduction of alien species such as redfin perch perch, are thought to have reduced larval recruitment success that has prevented any substantial recovery in Murray cod abundance. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 28

30 6. Regional trends in fish abundance and distribution In addition to commercial fish data previously discussed, there is limited fish community survey data available to quantitatively assess standardised trends in abundance over historical time periods. This is because there is very little historical data that enables standardised effort to be calculated and what is available is patchily distributed across the Basin. The following discussion of regional trends is based on what data is available at a sub-basin scale, however, specific assessment of trends are restricted to only a few locations where longer term abundance data is available. 6.1 The Murray Region The most relevant historical data for the Murray Region is that collected by Langtry in the mid 1900s and reported in Cadwallader (1977). This data cover the Murray River and lower reaches of the Darling and Murrumbidgee drainages and Victorian tributaries. Data collated by Llewellyn (1983) also provides information on the distribution of fish within the New South Wales and ACT portions of the Murray drainage basin. The Llewellyn (1983) study amalgamated data from a number of sources, including museum records and surveys to build a dataset documenting fish distribution from 1960 through to However, no attempt was made to compare relative abundance across regions. The first study to assess standardised relative abundance across the Murray region, at least in New South Wales, was the NSW Rivers Survey, which surveyed 20 randomly selected sites in each of the Murray region (Murray, Murrumbidgee and Lachlan basins) in (Harris and Gehrke 1997). More recently the Murray-Darling Basin Commission Sustainable Rivers Audit (SRA) has been sampling fish communities throughout the region. A number of other targeted surveys have also been conducted around both, Victoria, NSW and ACT. There is also some long term fishway data from fishways on the Murray River at Euston (Mallen- Cooper and Brand 2007) and Torrumbary (Mallen-Cooper et al. 1995). The current status of native fish in the Murray region is best determined from the NSW River Survey and recent SRA data. However, historical trends can only be assessed through some qualitative comparisons between Langtry s data and recent surveys in similar locations and from long term fishway data. While data collected as part of the current project is not sufficient to qualitatively assess trends in abundance it is suitable to assess changes in the distribution of native and alien fish over time at broad regional scales Upper Murray (Murray River and tributaries above Lake Hume) The Upper Murray catchment includes the main Murray River and its tributaries above Lake Hume, including the Mitta Mitta River, all of which rise in the southern Alps and flow in a generally west north west direction. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 29

31 A total of 14 native and 8 alien species are present in collated records from the Upper Murray basin (Table 6.1). Two-spined blackfish and mountain galaxias are the most widespread and frequently sampled native species. Macquarie perch has also been recorded at a high percentage of sites, although this is likely to be biased due to a large number of targeted Macquarie perch surveys in Lake Dartmouth and upstream tributaries. Brown trout, rainbow trout, redfin perch and carp are the most widespread and frequently surveyed alien fish. Most species have been recorded within the last ten years, except for freshwater catfish, which were last recorded in 1977 and flat-headed galaxias, which were last recorded in Stocking is likely to have sustained the presence of golden perch, Murray cod and trout cod. Climbing galaxias first appeared in 1989 and is considered to have been translocated from the Snowy River catchment via the Snowy Mountains Hydro-electric Scheme (Waters et al. 2002). Alien species first appeared in the survey record in the late 1960s and early 1970s, although anecdotal information indicates that redfin perch and brown trout were present in the 1930s (see below). n Table 6.1 Species present as a percentage of all surveys and all sites sampled in the Upper Murray Basin including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Carp Gudgeon Climbing Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Trout Cod Two-spined Blackfish Aliens Atlantic Salmon Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Rainbow Trout Redfin perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 30

32 Total surveys / sites sampled Across zones a total of 10 native species have been recorded in the montane zone, 11 in the upland zone and 15 in the slopes zone. Figure 6-1 shows the distribution of species based on presence at percentage of sites surveyed using either netting or electrofishing techniques; most sites have been surveyed using electrofishing, predominantly from the mid 1980s onwards. 100 Netting % of sites surveyed slopes netting upland netting montane netting 0 Australian Smelt Climbing Galaxias Flatheaded Gudgeon Flatheaded Galaxias Golden Perch Macquarie Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Trout Cod Two-spined Blackfish Western Carp Gudgeon Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin Perch % of sites surveyed Ele ctrofis hing slopes electrofishing upland electrofishing montane electrof ishing 0 Australian Smelt Climbing Galaxias Flatheaded Gudgeon Flatheaded Galaxias Golden Perch Macquarie Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Trout Cod Two-spined Blackfish Western Carp Gudgeon Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin Perch n Figure 6-1 Distribution of fish across SRA zones in the upper Murray Basin fish species at % of sites surveyed using netting (upper) and electrofishing (lower) techniques. Number of sites surveyed slopes netting 48, upland netting 58, montane netting 10, slopes electrofishing 87, upland electrofishing 133, montane electrofishing 59. Brown trout were the most widespread species across most zones in both netting and electrofishing surveys. In electrofishing surveys two-spined blackfish and mountain galaxias are the most widespread native species. Two-spined blackfish tend to favour the slope and upland zones while mountain galaxias are evenly distributed across all zones. Macquarie perch are prevalent in the upland zone in netting surveys but not in electrofishing surveys. This is due to the large number of Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 31

33 netting surveys targeting Macquarie perch in and upstream of Lake Dartmouth, so the distribution of fish across zones is probably best represented through electrofishing rather than netting surveys in this basin. Species that have been recorded in the basin but have not been represented in netting or electrofishing surveys are freshwater catfish, of which one was recorded in the Mitta Mitta River downstream of the Dartmouth Dam site in 1977, Atlantic salmon and carp x goldfish. There is little historical survey data available for the Murray River and tributaries upstream of Lake Hume. The earliest record in the database collated for this project is for a single golden perch recorded in 1949 at Burrowye. The first surveys to contain effort data were conducted on the Mitta Mitta River in the early 1970s as part of assessing the impacts of the construction of Dartmouth Dam (Turnbridge 1978). However these surveys used rotenone so abundance was expressed as number of fish per hectare and is not easily comparable to netting or electrofishing surveys. Netting surveys containing effort data (soak times) have been undertaken in and upstream of Dartmouth Dam as part of Macquarie perch studies in the 1990s. Most recently, sites have been sampled in the Mitta Mitta catchment for the Sustainable Rivers Audit using a combination of electrofishing and small bait traps. Due to the lack of historical abundance data, differences in survey techniques and relatively low number of sites where repeat surveys have been undertaken it is difficult to assess historical trends in abundance. However, a significant body of anecdotal recollections from the early to late 1900s has been collated by Will Trueman (2007). Trueman (2007) presents anecdotal evidence of trout cod, Murray cod and Macquarie perch being captured in good numbers in the Murray River and tributaries upstream of Albury in the late 1800s and early 1900s. Both Murray cod and trout existed in the Murray River around Woodonga with Murray cod prevalent to around Burrowye, upstream of which trout cod became more prevalent. In the Mitta Mitta River, Murray cod were more prevalent in the lower reaches to around Banimboola (near Dartmouth townships), while trout cod extended well upstream to around the Omeo area. Macquarie perch were reported in good numbers throughout all water ways, even in to higher elevation areas. Silver perch, golden perch and freshwater catfish were also reported in reasonable numbers in the lower reaches, catfish in particular were common in billabongs along the Murray and Mitta Mitta Rivers. Anecdotal evidence indicates that native fish numbers began to decline in the early 1900s. Alien species, notably redfin perch and brown trout extended into the upper parts of the Murray River in the 1930s, this along with overfishing, the construction of Hume Dam and drought are thought to have triggered the decline in native species abundance; it is also thought that alien species were better able to recolonise following drought, hence out-competing native species (Trueman 2007). In the Mitta Mitta River similar declines in trout cod and Macquarie perch abundance occurred, although in the upper parts of the catchment mining and associated habitat destruction, such as siltation, were likely the major causes of declines (Trueman 2007). By the 1930s catfish, golden Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 32

34 perch and silver perch were almost extinct from the upper Murray and Mitta Mitta Rivers (Trueman 2007). In the early to mid 1970s surveys in the Mitta Mitta River around and downstream of the proposed Dartmouth Dam showed that Murray cod, trout cod and Macquarie perch were all present in the system, blackfish, Australian smelt, southern pygmy perch and Galaxias sp. were also present (Turnbridge 1978). Turnbridge (1978) concluded that trout cod and Macquarie Perch would disappear from the Mitta Mitta River in the area that would become inundated by the dam. He also suggested that at the time of the study the downstream section of the Mitta Mitta River was one of the few remaining Victorian waters with a viable population of large Murray Cod and concluded that they may also disappear from the river unless high water temperatures could be maintained during spawning periods. Following dam construction Koehn et al. (1995) re-examined the fish fauna of the Mitta Mitta River below Dartmouth Dam. They re-sampled the same sites as those sampled in the pre-dam studies. During the post-dam fish survey no Murray cod, trout cod or Macquarie perch was recorded in the Mitta Mitta River downstream of the dam, in addition, the numbers of brown trout had increased approximately four fold. The authors concluded that the construction and operation of Dartmouth Dam, and in particular the cold water released from the dam during critical spawning periods, was responsible for the loss of resident trout cod, Murray cod and Macquarie perch populations from the Mitta Mitta River downstream of the dam and that colder waters over the summer period had favoured brown trout. Recent modelling of the impacts of cold water on conditions for native fish survival in the Mitta Mitta River downstream of Dartmouth Dam indicate that cold water releases have substantially reduced the number of days when temperature would have been suitable for spawning, and egg and larval survival for Murray cod and that for the ten years from 1988 to 1997 not one year would have experienced a temperature regime deemed suitable for successful spawning (SKM 2004). Further, it is estimated that temperatures during the spawning period would need to increase by 5-6 O C in order to remove temperature related threats to Murray cod spawning (Todd et al. 2005). Murray cod are still occasionally caught by anglers in the lower Mitta Mitta River and Murray River upstream of Hume Dam. However, these fish are likely to be from stockings in Hume Dam and some Murray tributaries, such as Cudgewa Creek during the 1990s and early 2000s (Victorian Department of Natural Resources and Environment and Victorian Department of Primary Industries native fish release records). While Macquarie perch have not been recorded in the lower Mitta Mitta River since the construction of Dartmouth Dam (Koehn et al. 1995) they initially thrived in the new impoundment and retained viable spawning populations in the Mitta Mitta River upstream of the impoundment Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 33

35 (Cadwallader 1986). However, they have subsequently undergone a substantial decline in abundance (Figure 6-2), probably due to falling lake productivity after initial filling and a reduction in spawning success in the Mitta Mitta River (Douglas 2003) Jul 94 Jan 95 Jul 95 Jan 96 Jul 96 Jan 97 Jul 97 Macquarie perch CPUE Jan 98 Jul 98 Jan 99 Jul 99 Jan 00 Jul 00 Jan 01 n Figure 6-2 Macquarie perch relative abundance in Dartmouth Dam and inflowing tributaries (combined sites) using netting techniques There is little data available to assess the status of smaller native fish such as river blackfish, twospined blackfish and galaxias species. Data collated for the current project is insufficient to assess historical trends in these species, although as indicated above two-spined blackfish and mountain galaxias appear to be the most widespread native species in the basin based on more recent surveys. Of the alien species present in the basin brown trout, rainbow trout, redfin perch perch and carp dominate. Anecdotal records indicate trout and redfin perch have been present in the upper Murray since the early 1900s. Gilligan and Rayner (2007) suggested that carp were present in Lake Hume, and hence the upper Murray River from at least 1977 onwards. Although there is an earlier record of carp from 1973 in the Mitta Mitta River around Eskdale in the data collected for this project. Hence carp likely arrived in the upper Murray and tributaries in the early 1970s. Currently, their abundance in the upper Murray is the lowest off all NSW basins in the MDB, at a catch per hour of around ten fish compared with the Mid Murray of around 20 fish per hour and the Murrumbidgee of around 140 fish per hour (Gilligan and Rayner 2007). Further, the authors consider that further Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 34

36 expansion of their distribution in the upper Murray, above Khancoban pondage is likely to be limited by natural barriers to fish passage, although they do exist at higher elevations in the Murrumbidgee catchment Mid Murray (Lake Hume to Darling River Junction) A total of 19 native species and 7 alien species are present in collated records from the mid Murray basin (Murray River and anabranch streams from Lake Hume to Darling junction) (Table 6.2). Golden perch, Australian smelt, Silver perch, Murray cod and carp gudgeons have been most frequently recorded in surveys (irrespective of method) with golden perch recorded in 39.5% of all surveys. Australian smelt and carp gudgeons appear most widely distributed, present at 35.3% and 32.9% of sites surveyed respectively; Murray cod was present at 31.1% of sites surveyed. Of the alien fish carp were the most dominant, being present in 51.5% of all surveys and at 52.1 % of sites surveyed. Redfin perch, goldfish and eastern gambusia were also widely recorded at 20-30% of sites. n Table 6.2 Species present as a percentage of all surveys and all sites sampled in the Mid Murray including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Climbing Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Short-headed Lamprey Silver Perch Southern Pygmy Perch Spangled Perch < Trout Cod Un-specked Hardyhead Alien Brown Trout Carp Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 35

37 Goldfish Eastern gambusia Oriental Weatherloach Redfin perch Tench Total surveys / sites sampled Figure 6-3 shows the distribution of species based on presence at percentage of sites surveyed using either netting or electrofishing techniques. Most sites have been surveyed using electrofishing (64 sites), predominantly from the mid 1980s onwards, 48 sites have been surveyed using netting from 1971 onwards. There is considerable variation in the distribution of fish when netting and electrofishing methods are compared. Australian smelt appear widespread and present at more than 60% of sites surveyed using either netting or electrofishing. Bony herring appear most widespread when netting surveys have been used but have only been captured at around 16% of sites where electrofishing has been used. Some species have only been recorded using one or the other technique. For example, climbing galaxias, Murray hardyhead and Macquarie perch have only been sampled using netting techniques while silver perch and trout cod have only been sampled using electrofishing. Carp are the most widespread alien species, present at nearly 100% of sites where electrofishing has been used. Redfin perch are also widespread and present at over 90% of sites where netting has been used. % of sites surveyed Australian smelt Bony herring Carp gudgeons Climbing galaxias Flatheaded galaxias Flatheaded gudgeon Un-specked hardyhead Golden perch Murray hardyhead Macquarie perch Murray cod Murray-Darling Rainbowfish River blackfish electrofishing netting Short-headed Lamprey Silver perch Trout cod Brown trout Carp Goldfish Mosquitofish Oriental weatherloach Redfin perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 36

38 n Figure 6-3 Distribution of fish across the mid Murray Basin fish species at % of sites surveyed using netting and electrofishing techniques. Number of sites surveyed netting 48, electrofishing 64. Species that have been recorded in the basin but have not been represented in netting or electrofishing surveys (i.e. specific capture method is not indicated in the data collated) are freshwater catfish, southern pygmy perch and southern purple-spotted gudgeon. Data collected in the late 1940s and early 1950s along the Murray River by Langtry and reported in Cadwallader (1977), along with fishway data collected from the Euston Weir fishway in the late 1930s and early 1940s (Mallen-Cooper and Brand 2007), provides some of the earliest assessments of the relative proportion of various native fish species along the Murray, and also provides anecdotes regarding the status of the fishery. The Langtry data can be difficult to interpret because specific details on gear and effort are not provided. Different techniques were used in different locations, for example drum versus mesh nets, no indication is provided as to the number of gear units or the actual time spent fishing, for example A licensed fisherman collected fish on 21 days in each of the three months of September, October and November, and The closed water was fished for nine weeks, the open water for two weeks. and data is only reported for the more commercially or recreationally important species. However, the data does provide an indication of the relative proportion of key species to the total catch (Table 6.3) and for some locations can be compared with data from more recent times collected in similar location. Figure 6-4 shows a comparison in fish community composition between 1937 and current in the Barmah region and Figure 6-5 shows a comparison in fish community composition between 1950 and current downstream of Yarrawonga. These plots show a comparison of relative proportions of key species to total catch. The 1937 and 1950 survey used gill and drum nets while the recent surveys used electrofishing. Small fish were excluded from the comparison because they were not reported in the 1937 or 1950 data, although small native species such as Australian smelt and gudgeon sp. are numerically dominant in more recent surveys. While total catch is presented in the plots it is not possible to assess trends in abundances because effort data is not comparable between historic and contemporary surveys. In 1949/50 golden perch, silver perch and Murray cod dominated the catch in the Murray River and some anabranches from downstream of the Darling junction to Burramine (downstream of Yarrawonga Weir). Murray cod and silver perch were most widespread, although golden perch tended to dominate the catch when present. Silver perch were generally in relatively lower abundance than Murray cod, although they represented the greatest proportion of fish moving through the Euston Weir fishway in ; 65.4% of fish were silver perch from a total of 25,544 that moved through the fishway (Mallen-Cooper and Brand 2007). Golden perch were common in the Murray River downstream of Yarrawonga Weir but absent upstream, although they Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 37

39 were known to be present in the area prior to the construction of the weir in 1939 (Cadwallader 1977). A comparison of fish community composition between open and closed waters (closed to drum netting) in the Boundary Bend area near the junction of the Murray and Murrumbidgee Rivers showed that in closed waters golden perch and silver perch made a relatively large contribution to the catch compared to Murray cod, which represented a greater proportion of the catch in the open water. Langtry attributed this to the tendency for golden perch and silver perch to form shoals that made them susceptible to being caught in large numbers in drum nets, hence their relatively greater abundance in the closed waters were drum netting was not permitted (Cadwallader 1977). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 38

40 n Table 6.3 Relative proportion (%) of species contributing to total catch for sites along the Murray River downstream of the Darling Junction to downstream of Lake Hume in 1949/1950 (Data source Cadwallader 1977). Species Lake Victoria Frenchmans ck Rufus Rv Locks 7, 8 & 9 Boundary bed Burramine Yarrawonga weir Brimin Corowa Surveys conducted between September and November 1949 Surveys conducted between September and December 1950 Closed water Open water Native species River Billabongs Golden perch Silver perch Closed water Near Lake Moudamere Murray cod Trout cod Macquarie perch Bony bream Gudgeon sp Freshwater catfish 2.2 Alien species Carp Redfin perch perch Tench Brown trout Total fish Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 39

41 Murray River Barmah area 100% % 80% 70% Redfin perch Carp Brown trout % of catch 60% 50% 40% % 20% 10% 0% Sep 1937 Oct 1937 (1) Oct 1937 (2) Nov 1937 Sep 1994 Dec 1994 Aug 1995 Dec 1995 Mar 1998 Dec 1998 Jan 2005 total catch Trout cod Silver perch Murray cod Macquarie perch Golden perch Total % native 0 n Figure 6-4 Percentage contribution by species to total catch (excluding small species). The plot compares data collected from several locations in the Barmah area by J. A. Tubb in 1937 (reported in Cadwallader 1977) with data from 1994 to 2005 in the Murray River in the same region. In 1937 and 1950 the catch was dominated by large native species, particularly golden perch, but also Macquarie perch, Murray cod, trout cod and to a lesser degree silver perch. Alien species, predominantly tench and redfin perch, contributed around 20% or less of the catch depending upon location. By contrast, from 1990 onwards alien species have dominated the catch, in some instances representing 100% of the catch (Figure 6-4 and Figure 6-5). In most recent years carp were the dominant species, although redfin perch have also made a large contribution to the catch in some years. In the last 10 to 15 years the Murray River in the Barmah area appears to have a greater proportion of alien species than further upstream at Burramine. The Burramine area encompasses the trout cod protection area between Yarrawonga Weir and Tocumwal and this may have helped to overall retain a relatively diverse native fishery where golden perch, Murray cod, trout cod and silver perch are still recorded in proportions not dissimilar to those recorded in 1950, although there is high variability between surveys (Figure 6-5). Interestingly, in 2005 no carp were recorded in the Barmah area and golden perch made a relatively greater contribution to the total catch than on other occasions (Figure 6-4). Also, while no published data is available, surveys conducted in the Murray River in the Barmah forest area in late 2005 in response to an environmental flow release that flooded the Barmah forest in October 2005 collected large number of golden perch and silver perch eggs and larvae (A. King, ARI unpublished). This indicates that Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 40

42 golden perch and silver perch are still present in this part of the river. Murray cod and a number of smaller species were also detected spawning, possibly in response to the flood event. Murray River Cobram-Yarrawonga area 100% % Tench Redfin Carp Brown trout % catch 60% 40% total catch Trout cod Silver perch Short-headed Lamprey Murray cod 20% Macquarie perch Golden perch Total catch % natives 0% Dec-50 Jan-90 Oct-90 Sep-94 May-96 Mar-05 0 n Figure 6-5 Percentage contribution by species to total catch (excluding small species). The plot compares data collected from near Burramine (downstream of Yarrawonga) by Langtry in 1950 (reported in Cadwallader 1977) with data from 1990 to 2005 in the Murray River in the same region. Between 1938 and 1942 Macquarie perch were detected moving through the Euston Weir fishway in small numbers (Cadwallader 1977) and between 1940 and 1945 they represented 8.5% of the total number of fish moving through the fishway (Mallen-Cooper and Brand 2007). However by 1949 Langtry indicated that they were not present westward of Torrumbarry Weir and were only reported in reasonable abundance around Burramine, downstream of Yarrawonga Weir. The authors suggested that the construction of Euston Weir may have drowned out the most downstream spawning habitat for Macquarie perch in the Murray River and that the migrations of the late 1930s and early 1940s represented the last migrations for this species in the region. Macquarie perch were present in the Barmah area in 1937 and in the Burramine area in 1950 however, they have not been recorded in recent surveys (Figure 6-5 and Figure 6-4). Anecdotes from recreational fishers indicate that Macquarie perch were common in the Murray River until the 1930s and 40s, after which they became very scare, and had mostly disappeared by the 1950s (Will Trueman, unpublished). The last record of Macquarie perch in the Barmah to Yarrawonga region Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 41

43 is from the early 1970s (Cadwallader 1981 and supported by data collected for this project). While the most recent Macquarie perch records upstream of Yarrawonga are anecdotal from near Albury in 1974 and 1977 (Walker and Hillman 1977). Of note in the 1949/50 data is the very low contribution that alien species made to total catch at and downstream of Boundary Bend compared to Burramine and upstream (Table 6.3). In the upstream areas, even in 1950, redfin perch, tench and brown trout contributed greater than 50% of the catch in some locations, particularly in billabongs and in Yarrawonga Weir (Lake Mullwala), where no natives were recorded. Langtry reported that following the construction of Hume Dam and Yarrawonga Weir in the 1920s and 1930s there was a decline in native fish in the region, particularly golden perch and silver perch upstream of Yarrawonga Weir. Also, copper sulphate was used to control algal blooms in Hume Dam from 1930 to 1934 and there are reports of significant fish kills associated with releases of water from the dam as far downstream as Echuca (Cadwallader 1977). It is suggested that following the fish kills redfin perch and tench rapidly colonised the river and out competed native fish to the extent that native fish populations never recovered. Yarrawonga Weir also acted as a barrier to fish passage, particularly for golden perch and silver perch, hence they probably never recolonised the Murray River upstream of Yarrawonga following the fish kills and in 1950 Langtry suggested that golden perch were no longer present in the Murray River upstream of the weir (Cadwallader 1977). More recently there have been occasional records of golden perch from the early 1990s in the Murray River upstream of Yarrawonga, in the lower Ovens River and in Lake Hume, however there are no records post Database records show that in the 1980s and early 1990s golden perch were stocked in Lake Mulwalla and the lower Ovens. Stocking of golden perch ceased in 1995 and was replaced with trout cod. So it is likely that the few records of golden perch from the Murray River in the early 1990s are of stocked fish from the Ovens River, or the occasional fish that has negotiated the fish lock on Yarrawonga Weir, and that because no small golden perch have been recorded since stocking ceased they are unlikely to have re-established self sustaining populations upstream of Yarrawonga. Along with the barrier to fish passage associated with the weir, changed flow conditions and cold water temperatures in the releases from Hume Dam are likely to have limited their ability to recolonise the Murray River upstream of Yarrawonga (SKM 2007a). Silver perch are now also no longer present in the Murray River upstream of Yarrawonga Weir. In the early 1900s they were recorded as far upstream as the Mitta Mitta River around Dartmouth and the upper Murray around Burrowye (Will Trueman unpublished data) but appeared absent from around the 1930s onwards, coinciding with the construction of Hume Dam and Yarrawonga Weir. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 42

44 6.1.3 Lower Murray (Darling River Junction to Murray mouth) A total of 20 native species and 7 alien species are present in collated records from the lower Murray basin (Darling junction to the Murray Mouth) (Table 6.4). Although a number of additional species are known to be present, or historically present in the basin but have not been reported in the data collated (i.e. pouched lamprey, short-finned eel, climbing galaxias, flat-headed galaxias, small-mouthed hardy head, estuary perch, Yarra pygmy perch). The earliest records are from the early 1900s of Murray cod, bony herring, silver perch, short-headed lamprey, tupong and tench, carp were first recorded in Bony herring and Australian smelt appear most common in surveys and are widely distributed across survey sites (Table 6.4). Golden perch, carp gudgeons, flat-headed gudgeon, Murray- Darling rainbowfish and un-specked hardyhead also appear relatively common, being present in greater than 20% of total surveys and sites. Of the alien species carp, goldfish and eastern gambusia dominate the survey record. Figure 6-6 shows the distribution of species based on presence at percentage of sites surveyed using either netting or electrofishing techniques. Approximately 50 sites have been surveyed with either electrofishing or netting (although not necessarily the same sites). Netting surveys stemmed from the early 1980s onwards and electrofishing surveys from the late 1990s onwards, predominantly focused on fishway monitoring. Bony herring, Australian smelt, golden perch and Murray-Darling rainbow fish have been recorded at more than 70% of sites surveyed. Flat-headed gudgeon, un-specked hardyhead and carp gudgeons are also commonly recorded. Carp appears to be the most dominant alien species, recorded at more than 80% of sites. Species present in the data collated using methods other than netting or electrofishing (including unknown) are southern purple-spotted gudgeon, short-headed lamprey and tench. Based on standardised surveys downstream of some locks since 2001, bony herring are the most abundant species, followed closely by carp and then Australian smelt (Figure 6-7 the data presented for Lock 2 are typical for other locations in the lower River Murray downstream of locks although surveys downstream of locks with no fish passage provision, such as Lock 2, may over estimate abundance due to the accumulation of fish during the spring and summer periods when most movement is likely to occur). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 43

45 n Table 6.4 Species present as a percentage of all surveys and all sites sampled in the Lower Murray Basin including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Common Galaxias Dwarf Flat-headed Gudgeon Flat-headed Gudgeon Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive Perchlet River Blackfish Short-headed Lamprey Silver Perch Southern Purple-spotted Gudgeon Southern Pygmy Perch Tupong Un-specked Hardyhead Alien Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 44

46 electrofishing netting % of sites surveyed Australian Smelt Bony Herring Carp Gudgeons Common Galaxias Flat-headed Gudgeon Dwarf Flat-headed Gudgeon Un-specked Hardyhead Freshwater Catfish Mountain Galaxias Golden Perch Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive perchlet River Blackfish Short-headed Lamprey Silver Perch Southern Pygmy Perch Tupong Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin Perch n Figure 6-6 Distribution of fish across the lower Murray River Basin fish species at % of sites surveyed using netting and electrofishing techniques. Number of sites surveyed netting 52, electrofishing 51. Relative abundance (CPUE) Jul-01 Jan-02 Jul-02 Jan-03 Jul-03 Jan-04 Jul-04 Jan-05 Australian Smelt Bony Herring Carp Carp Gudgeons Flatheaded Gudgeon Un-specked Hardyhead Golden Perch Goldfish Murray Cod Murray-Darling Rainbow f ish Redf in Perch Silver Perch n Figure 6-7 Relative abundance of native and alien species in standardised seasonal surveys downstream of Lock 2 since 2001 (data collected for the tri-state fishway program). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 45

47 There is little information available to quantify historic fish abundance in the lower Murray basin and effort data is only present from 2001 onwards. Some commercial data exists, as discussed in Section 5, which indicates an historical decline in abundance of Murray cod. Lloyd and Walker (1986) examined the distribution of small freshwater fish species in the Lower Murray River channel, anabranches, billabongs, backwaters and tributaries within South Australia and found that most small bodied native fish had patchy, low density distributions. Common and widespread species included carp gudgeon, Australian smelt, flat-headed gudgeon, bony herring, un-specked hardyhead and Murray-Darling rainbowfish. Less common species and ones restricted to isolated habitats included Murray hardyhead, dwarf flat-headed gudgeon, mountain galaxias and common galaxias. A number of species considered endangered were also recorded, these included river blackfish, southern pygmy perch and olive perchlet. Lloyd and Walker s 1983 record of olive perchlet was the last for the area, some individuals were subsequently translocated from the Darling River in QLD but it is now considered extinct in South Australia (Hammer and Walker 2004). Southern purple-spotted gudgeon was not recorded by Lloyd and Walker (1986), although some museum records existed from the early 1970s. It has also not been recorded since and is also presumed extinct in South Australia apart from an isolated translocated population (Hammer and Walker 2004). More recently Hammer and Walker (2004) provided a catalogue of native freshwater fishes in South Australia. They listed a total of 35 native species from the MDB in South Australia, including historical records of climbing galaxias in the eastern Mt Lofty Ranges (they are present in the western Mt Lofty Ranges) and Macquarie perch and trout cod, which were thought to have progressed downstream from time to time from populations centred in the mid and upper reaches of the Murray River (Cadwallader 1977). Hammer and Walker (2004) also documented a range extension for Yarra pygmy perch into the South Australian MDB, with recent captures from Lake Alexandrina. A range of diadromous fish have been recorded in the lower River Murray. These include estuary perch, tupong, shortfinned eel, pouched lamprey, shortheaded lamprey and some Galaxias species (Hammer and Walker 2004). The construction of the Goolwa barrages in the 1940s reduced the ability of diadromous species to pass between the lower lakes and the Coorong and the sea. However, the recent construction of fishways at the Goolwa and Tauwitchere Barrages has reinstated fish passage, which will benefit many of these species. Ongoing monitoring is examining the effectiveness of the new fishways (Ye et al. 2002). Under current conditions bony herring appears to be the most abundant native species and Puckridge and Walker (1990) suggest it is the only large native fish that hasn t experienced a decline in abundance in the Lower Murray River since the advent of flow regulation. They further suggest that a decline in Murray cod abundance may have favoured bony herring. Ebner (2006) Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 46

48 found that bony herring comprised 7.9% of prey items in Murray cod compared with carp (23.8%) and decapods (54%). In the absence of carp, bony herring would likely be a much more significant prey item and a reduction in Murray cod abundance may reduce predation pressure on bony bream Victorian tributaries (Kiewa, Ovens, Broken, Goulburn, Campaspe, Loddon, Avoca) Several major tributaries enter the Murray River from Victoria downstream of Lake Hume; from east to west they are the Kiewa, Ovens, Goulburn-Broken, Campaspe and Loddon Rivers. The Avoca and Wimmera Rivers are also located in the MDB, the Avoca River only reaches the Murray during flood events while the Wimmera River terminates in a series of lakes that do not reach the Murray River, even in times of flood. Each of these catchments has similar physiography, rising on the northern slopes of the Great Dividing Range and flowing north across upland, slope and lowland zones. Rainfall, and hence discharge per unit area, is higher in the east and diminishes across the more westerly catchments. All catchments have been regulated to some degree through the construction of dams for irrigation or hydroelectricity generation. Kiewa River Twelve native and 7 alien species are present in collated survey records from the Kiewa River (Table 6.5). Mountain galaxias and two-spined blackfish were the most frequently surveyed native species being present in 15.4 % and 18.2% of surveys respectively and recorded at 28.4% and 20.9% of surveyed sites respectively. Less frequently encountered species included Australian smelt, gudgeon species, river blackfish and southern pygmy perch. Golden perch and Murray cod were occasionally recorded. Macquarie perch have not been recorded since Brown trout is the dominant alien species, recorded in 47.6% of surveys and at greater than 50% of surveyed sites. Rainbow trout and redfin perch are also relatively widespread. Carp have been recorded in around 10% of surveys and at around 13% of surveyed sites. Figure 6-8 shows the distribution of fish across lowland, slopes and upland zones separated by electrofishing and netting survey methods. Ten native species have been recorded in electrofishing surveys and only 5 or 6 species have been recorded in netting surveys (netting survey data is equivocal with respect to blackfish). Across zone, mountain galaxias and two-spined blackfish favour slopes and upland sites while river blackfish, gudgeons and Murray cod favour lowland sites. Brown and rainbow trout also favour slopes and upland sites while carp, and to a lesser degree redfin perch, dominate lowland sites. Climbing galaxias has been recorded in the catchment, indicating that they have travelled downstream of Lake Hume following translocations to the Upper Murray from the Snowy catchment via the Snowy Mountains Hydro scheme in the early 1990s (Waters et al. 2002) and are now beginning the colonise tributary streams downstream. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 47

49 n Table 6.5 Species present as a percentage of all surveys and all sites sampled in the Kiewa River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Carp Gudgeon Climbing Galaxias Flat-headed Galaxias Flat-headed Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Two-spined Blackfish Alien Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 48

50 100 Electrofishing % sites surveyed Lowland Slopes Upland Australian Smelt Carp Gudgeon Climbing Galaxias Flatheaded Gudgeon Golden Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Two-spined Blackfish Brown Trout Carp Mosquitofish Rainbow Trout Redfin Netting 100 % sites surveyed Lowland Slopes Upland Carp Gudgeon Flatheaded Galaxias Mountain Galaxias River Blackfish Blackfish sp. Southern Pygmy Perch Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin Tench n Figure 6-8 Distribution of fish across the Kiewa River Basin fish species at % of sites surveyed using netting and electrofishing techniques. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 49

51 There is insufficient historical data to undertake specific analysis of trends in abundance in the Kiewa River and limited historical or anecdotal information exists. In some of the earliest records from around 1824 and 1825 explorers recorded the presence of cod and bream in the Murray River around Albury and lower Kiewa River and fish similar to carp (likely to have been freshwater catfish based on the presence of barbels) in the billabongs (Scott 2005). From 1928 onwards Macquarie perch, Murray cod, trout cod (referred to as blue cod) and blackfish were commonly take in the Kiewa River around Tawonga and Dederang (Trueman 2007). But by 1948 Langtry indicated these species were rarely taken even though the river appeared ideal habitat (Cadwallader 1977). Langtry further noted that the predominant fish in 1948 were brown trout and rainbow trout and that carp were rare. There is an unsubstantiated report of a small population of trout cod and Macquarie perch surviving in the Kiewa River near Mt Beauty in to the 1950s (Trueman 2007). It is suggested by Trueman (2007) that bushfires in the Kiewa catchment in 1939 represented a turning point in the fish community. Native fish mostly failed to recover from the impacts of the fires possibly because potential sources of recolonisation from the Murray River had also substantially decline in the 1930s due to the construction of Yarrawonga Weir and hence the inability of fish to migrate upstream from the mid reaches of the Murray River, where according to Langtry, most species were still present in good numbers (Cadwallader 1977). Following the fires alien species, particularly salmonids dominated, as noted by Langtry in Further, the construction of hydro-electric schemes, snag removal and extensive stocking of salmonids are likely to have prevented any substantial recovery in native fish populations. The Sustainable Rivers Audit recorded 11 of a predicted 16 native species present in the Kiewa River, natives contributed 43% of average abundance but just 10% of average biomass per site (MDBC 2007). Ovens River Sixteen native and 10 alien species are present in collated survey records from the Ovens River (Table 6.6). Two-spined blackfish were the most frequently surveyed native species, being present in 39.2% of surveys and recorded at 43.5% of sites. Mountain galaxias and Murray cod were recorded in around 10% of surveys and at 10% of sites. An increasing number of fish species have been recorded in the Ovens Basin compared to other upstream tributaries of the Murray River because it represents a transitional zone between upland/slope species and lowland species, including bony herring, un-specked hardyhead, Murray-Darling rainbowfish and silver perch, albeit at very low frequency. Brown trout is the dominant alien species, recorded in 46.3% of surveys and at greater than 50% of surveyed sites. Rainbow trout and redfin perch are also relatively widespread. Carp have been recorded in around 8% of surveys and at around 9% of sites. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 50

52 Figure 6-9 shows the distribution of fish across lowland, slopes, upland and montane zones separated by electrofishing and netting survey methods. Nine native species have been recorded in electrofishing surveys and 11 species have been recorded in netting surveys. As in the adjacent Kiewa catchment, across zones mountain galaxias and two-spined blackfish favour slopes and upland sites while river blackfish, gudgeons and Murray cod favour lowland sites. Brown and rainbow trout also favour slopes and upland sites while carp, and to a lesser degree redfin perch, dominate lowland sites n Table 6.6 Species present as a percentage of all surveys and all sites sampled in the Ovens River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Flat-headed Galaxias Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Short-headed Lamprey Silver Perch Southern Pygmy Perch Trout Cod Two-spined Blackfish Un-specked Hardyhead Alien Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Oriental Weatherloach Quinnat Salmon Rainbow Trout Redfin perch Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 51

53 Electrofishing Lowland Slopes Upland Montane % sites surveyed Australian Smelt Carp Gudgeon Golden Perch Mountain Galaxias Murray Cod River Blackfish Southern Pygmy Perch Two-spined Blackfish Un-specked Hardyhead Brown Trout Carp Goldfish Mosquitofish Oriental Weatherloach Rainbow Trout Redfin 100 Netting 90 Lowland 80 Slopes % sites surveyed Upland Montane Australian Smelt Carp Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish Southern Pygmy Perch Trout Cod River Blackfish Two-spined Blackfish Brown Trout Carp Goldfish Goldfish X Carp Mosquitofish Oriental Weatherloach Rainbow Trout Redfin Tench n Figure 6-9 Distribution of fish across the Ovens River Basin fish species at % of sites surveyed using netting and electrofishing techniques There is insufficient historical data to assess quantitative trends in fish abundance in the Ovens River although a large body of anecdotal information exists. In the early 1900s it appears Murray cod, trout cod, Macquarie perch and blackfish were present in good numbers in the lower and mid reaches of the Ovens River and tributary streams such as the Buffalo River (Trueman 2007). Freshwater catfish also appeared in good numbers, mostly in billabongs, and golden perch and silver perch were occasionally encountered (Trueman 2007). However, it would appear that by the Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 52

54 late 1930s and early 1940s the number of cod were declining, and as with the Kiewa River, runoff from bushfires in 1939 appeared to have contributed to fish kills in the basin. This is supported by the observations of Langtry in the late 1940s, who reported native fish were taken but not in great numbers, specifically, drum netting in the late 1940s in the lower Ovens between Wangaratta and the Murray River yielded 1 Murray cod, 5 trout cod, 5 Macquarie perch and 14 redfin perch and Langtry considered this to represent a poor catch of fish (Cadwallader 1977). Langtry also noted that silver perch were occasionally encountered but that golden perch were entirely absent, the later species being replaced in importance by Macquarie perch. Upstream of Wangaratta introduced brown trout and redfin perch dominated the fish community. Freshwater catfish was also described as abundant in the early 1900s, particularly in billabongs, but disappeared around the same time redfin perch where first notice in the catchment in the late 1930s (Trueman 2007). There are no records of freshwater catfish in the Ovens River in the data collected for the current project. Macquarie perch were common in the Buffalo River, a tributary of the Ovens River, but appeared to undergo a population decline in the mid 1950s after the construction of Lake Buffalo and the introduction of redfin perch (Lyon 2006). Despite this, the population has persisted and was augmented with stocking in the Buffalo, Rose and Dandongadale Rivers in the early 1990s (Lyon 2006). Surveys in the Buffalo River and tributaries in 2006 confirmed the continued presence of a breeding population of Macquarie perch upstream of Lake Buffalo, although numbers were low and patchily distributed (Lyon 2006). Recent surveys have also indicated the widespread distribution of Murray cod in the lower and mid Ovens River and the presence of an expanding adult trout cod population established on the basis of extensive stocking over the past ten years (Lyon 2006, DSE unpublished). As indicated by Langtry, golden perch were not present in the Ovens River in the late 1940s, although there are earlier anecdotal records (Trueman 2007). However, they are now regularly encountered in the lower Ovens River as a consequence of extensive stocking since 1982 (Brumley 1987, Lyon 2006). There is little information regarding the historical status of smaller native species in the Ovens River. Surveys carried out by the Victorian Department of Conservation and Environment from 1978 to 1985 (Baxter 1985, Brumley et al. 1987) reported brown trout, rainbow trout and blackfish (no distinguishment between river or two-spined blackfish) were widespread throughout the catchment. Smaller native fish, such as Australian smelt, mountain galaxias and southern pygmy perch had scattered distributions. In the early 2000s, the Sustainable Rivers Audit found a low diversity, although relatively high abundance, of small native fish, including Australian smelt, mountain galaxias, river and two-spined blackfish and carp gudgeons (MDBC 2004). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 53

55 Fish surveys undertaken during the 1970s and 1980s suggested the native fish community in the Ovens River was poor (Baxter 1985, Brumley et al. 1987), the later authors considered the Ovens River was suitable for native fish but it was not of high conservation value. More recently, results from the Sustainable Rivers Audit pilot assessment considered the Ovens River to be moderately to majorly modified with a low ratio of observed to expected native fish and a very high biomass of alien species, which contributed ~90% of total fish biomass across the basin (MDBC 2004). Alien species included carp, goldfish, trout, eastern gambusia, redfin perch and oriental weatherloach. Despite this, it would appear that the Ovens River Basin does have high conservation value. It is a stronghold for two-spined blackfish, supports a significant, albeit small, breeding population of Macquarie perch in the Buffalo River catchment and important populations of Murray cod and trout cod in the lower Ovens River itself. The relatively unregulated flow regime (Cottingham et al. 2001) and presence of abundant snag habitat (Treadwell 2002) in the lower Ovens River may contribute to the maintenance of this important habitat for large bodied species that have undergone significant declines elsewhere in the southern basin. Broken River Eighteen native and 9 alien fish species are present in collated survey records from the Broken River and Broken Creek (Table 6.7). River blackfish were the most frequently surveyed native species and were present in 31.3% of the surveys and collected at 28.7% of surveyed sites. Other native species to appear reasonably frequently in surveys and across sites were golden perch, mountain galaxias and Australian smelt, while the remaining natives were sampled infrequently. Of the alien species, brown trout, carp and goldfish were present in over 20% of surveys, although redfin perch dominated the surveys being present in 35.6% of surveys and at over 37% of surveyed sites. A relatively new comer, the oriental weatherloach, has recently started to appear in surveys, although in small numbers. Figure 6-9 shows the distribution of fish across lowland, and slopes zones using electrofishing and netting survey methods. Fourteen native species have been recorded in electrofishing surveys and 15 species have been recorded in netting surveys. Across zones, mountain galaxias, river blackfish and two-spined blackfish favour the slopes zone whereas carp gudgeons, Murray cod, Australian smelt, golden perch and Murray-Darling rainbowfish favour lowland sites. Of the alien species brown and rainbow trout favour slopes, while carp, goldfish, eastern gambusia and redfin perch, dominate lowland sites. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 54

56 n Table 6.7 Species present as a percentage of all surveys and all sites sampled in the Broken River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Climbing Galaxias Common Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Pygmy Perch Trout Cod Two-spined Blackfish Alien Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Oriental Weatherloach Rainbow Trout Redfin perch Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 55

57 % sites surveyed Electrofishing Carp Gudgeons Australian Smelt Common Galaxias Flatheaded Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Pygmy Perch Trout Cod Two-spined Blackfish Brown Trout Lowland Slopes Carp Goldfish Goldfish X Carp Mosquitofish Oriental Weatherloach Rainbow Trout Redfin n % sites surveyed Australian Smelt Bony Herring Figure 6-10 Distribution of fish across the Broken River Basin fish species at % of sites surveyed using netting and electrofishing techniques A substantial survey effort has been undertaken in the Broken catchment, typically associated with specific projects, for example, fishway monitoring, research projects and monitoring of stream restoration works. Unfortunately, the time frame over which these surveys have been undertaken is Carp Gudgeons Flatheaded Galaxias Netting Lowland Slopes Flatheaded Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Southern Pygmy Perch Trout Cod Two-spined Blackfish Brown Trout Carp Goldfish Goldfish X Carp Mosquitofish Rainbow Trout Redfin Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 56

58 limited to the past 20 years for netting surveys and 15 years for electrofishing surveys so the data is of limited value for assessing historical trends (Figure 6-11). Broken River survey summary Bank-mounted electrofishing 90 Boat electrofishing 80 Backpack Electrofishing Netting Other (angling, rotenone, observation) 600 Unknow n Number of sites surveyed per year Cumulative netting surveys w ith ef f ort Cumulative electrof ishing surveys w ith ef f ort Cumulative total surveys Translocation / stocking occurrences Cumulative number of sites surveyed Year 0 n Figure 6-11 Temporal distribution of survey effort (sites surveyed) by method in the Broken River. Note, database records rarely distinguish between netting types. The earliest records from the Broken catchment are for stockings of 100 redfin perch and 148 tench in 1912 and 1913/14 respectively. Redfin perch were stocked in to the Broken Creek near Numurkah and tench to the Broken River near Benella. Early records of native fish are for the translocation of 350 Murray cod and 350 Macquarie perch to the Broken River near Benalla in Two hundred Macquarie perch were also translocated to the Broken Creek near Tungamah in Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 57

59 Through the mid 1900s there are records from the Broken catchment of large bodied natives such as Murray cod, silver perch, Macquarie perch, freshwater catfish and golden perch. Smaller natives recorded through the mid 1900s included Murray-Darling rainbowfish, southern pygmy perch, blackfish, Australian smelt, flat-headed galaxias and carp gudgeon. Langtry reported that in the mid 1900s the Broken River..contains an abundance of Macquarie perch (Cadwallader 1977). Anecdotal information compiled by Trueman (2007) also attest to the presence of large numbers of Macquarie perch, two types of cod, blackfish, golden perch and freshwater catfish during the early and mid 1900s. Additional unpublished anecdotes provided by Will Trueman indicate Macquarie perch were common in Hollands and Ryans Creeks in the early to mid 1900s and Murray cod, freshwater catfish and blackfish were present in Broken and Boosey Creeks, along with the occasional golden perch and silver perch. A large fish kill c1928 in the Boosey Creek is thought to have virtually wiped out the cod in that stream (Will Trueman, unpublished data). Although the construction of fishways on weirs in the lower and mid Broken Creek in recent years has resulted in the establishment of a significant Murray cod population in this system (MAFRI 2000). More recent surveys associated with research being undertaken on the Broken River indicate that a relatively diverse native fish community is still present in the catchment, including a number of threatened species. Three years of survey in the Broken River downstream of Benella from June 2000-February 2003 recorded golden perch, Murray cod, carp gudgeons, river blackfish, Murray- Darling rainbowfish, common carp, redfin perch perch, goldfish and Eastern gambusia (Humphries et al. 2007). Native fish represented 85.7% of the catch, 49.6% of the total biomass and 56% of the species richness. In terms of numbers and biomass, golden perch dominated the native catch and carp the alien catch. In addition to those species above, earlier larval surveys from 1995 to 1999 also recorded Australian smelt, flat-headed gudgeon, carp gudgeon and galaxias species (Humphries et al. 2002). Surveys associated with fishway monitoring on the Broken River undertaken in 2000/2001 recorded the continued presence of silver perch in the lower Broken River (Close and Aland 2001). A number of projects are occurring in the Broken catchment to enhance native fish communities and much of the data collected for these projects is included in the data collected for the current project. There are records from the early 1990s for Macquarie perch in the Broken River between Benella and Swanpool and in Ryans, Hollands, Moonee and Blind Creeks. Subsequent to this trout cod and Macquarie perch were stocked in the Broken River, Hollands Creek and Ryans Creek and habitat improvement works undertaken (Tennant et al. 1996). Macquarie perch and trout cod continued to be recorded through the 1990 in the Broken River and surveys in 2005/2006 indicated the presence of a small breeding population of Macquarie perch in Holland s Creek, which is now the focus of a MDBC demonstration reach (Arthur Rylah Institute 2007). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 58

60 Golden perch have also been extensively stocked in the Broken River (over 500,000 since the early 1980s), and this may contribute to the high abundances recorded in previous surveys (Humphries et al. 2008), although golden perch larvae have also been recorded indicating that spawning does occur in the river (Humphries et al. 2002). In the recent Sustainable Rivers Audit for the Broken Creek native species represented 75% of the total number of fish captured but only half the expected number of native species were recorded and native species only contribute 1/3 of the total biomass (MDBC 2006). Goulburn River Over 2000 fish surveys across 1301 sites have been carried out in the Goulburn River Basin and 20 native and 11 alien species have been recorded (Table 6.8). Mountain galaxias were the most widespread native species being present at 21.6% of sites surveyed and in 16.8% of surveys. River blackfish and two-spined blackfish were also relatively widespread, being present at 18% and 15% of sites surveyed respectively. Macquarie Perch were recorded in 10.0% of the surveys and at 10.6% of sites. Trout cod, Murray cod, golden perch, flat-headed gudgeon, southern pygmy perch, Australian smelt and barred galaxias were recorded in less than 10% of surveys and sites. Most of the native species recorded in the catchment have been recorded since 1990, except short-headed lamprey, which was only recorded in 1913 and common galaxias, which was only recorded in 1978/79. Brown trout were the most widespread alien species, occurring in 45.6 % of surveys across 48.1% of sites. Rainbow trout, carp, and redfin perch were also relatively widespread. Figure 6-12 shows the distribution of fish across lowland, slopes and upland zones separated by electrofishing and netting survey methods. Australian smelt, carp gudgeons, flat-headed gudgeons, Murray-Darling rainbowfish, golden perch and Murray cod occurred mainly in lowland zones. Mountain galaxias, river blackfish and two-spined blackfish were distributed across all zones. Macquarie perch and trout cod were also present across all zones, although their representation in the data is probably biased by a large number of targeted surveys for these species in the Seven Creeks, which comprises slope and upland zones, and the lower Goulburn River. Barred galaxias is restricted to a few sites in the upland zone. Of the alien species, brown trout was recorded across all zones but predominantly the slopes and upland zones. Carp and redfin perch predominated in the lowland zone. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 59

61 n Table 6.8 Species present as a percentage of all surveys and all sites sampled in the Goulburn River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Barred Galaxias Bony Herring Carp Gudgeons Common Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Short-finned Eel Short-headed Lamprey Silver Perch Southern Pygmy Perch Trout Cod Two-spined Blackfish Alien Atlantic Salmon Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Quinnat Salmon Rainbow Trout Redfin perch perch Roach Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 60

62 n % sites surveyed % sites surveyed Australian Smelt Barred Galaxias Australian Smelt Barred Galaxias Carp Gudgeons Flatheaded Galaxias Electrofishing Bony Herring Carp Gudgeons Flatheaded Galaxias Flatheaded Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Short-finned Eel Netting Goldfish X Carp Silver Perch Southern Pygmy Perch Trout Cod Two-spined Blackfish Atlantic Salmon Brown Trout Carp Goldfish Figure 6-12 Distribution of fish across the Goulburn River Basin fish species at % of sites surveyed using netting and electrofishing techniques The earliest records of native fish in the Goulburn River are for Murray cod pre-1900 based on early explorer anecdotes (Scott 2005). Records from the early 1900s include short-headed lamprey, Macquarie perch, trout cod, silver perch, Galaxias species and Murray-Darling Lowland Mosquitofish Quinnat Salmon Rainbow Trout Redfin Roach Tench Flatheaded Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Short-finned Eel Southern Pygmy Perch Trout Cod Two-spined Blackfish Atlantic Salmon Brown Trout Carp Goldfish Goldfish X Carp Mosquitofish Rainbow Trout Redfin rainbowfish. Records indicate the introduction of tench to the Goulburn River in 1913, rainbow trout were record in 1936 and carp and redfin perch were first recorded in Survey records that include effort information are limited to post 1982 and are patchily distributed across the basin. Slopes Upland Lowland Slopes Upland Roach Tench Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 61

63 Anecdotally, Langtry reported that in the mid 1900s the Goulburn River carried the best population of native fish in Victoria with records of large numbers of Murray cod across a range of sizes captured downstream of Goulburn Weir (Cadwallader 1977). In addition, golden perch, silver perch, freshwater catfish and Macquarie perch were also commonly encountered, the later more so downstream of Goulburn Weir. A large body of anecdotal information on native fish in the Goulburn catchment in the early 1900s has been collated by Trueman (2007). This information attests to large numbers of Murray cod, trout cod and Macquarie perch being present along the main Goulburn River as far upstream as Jamieson (upstream of Lake Eildon) and tributary streams such as Hughes Creek, King Parrot, Yea River and Seven Creeks up to the Gooram Falls area. Golden perch and silver perch also appeared present in reasonable numbers in the lower and mid Goulburn River. Blackfish were widespread in the main channel and also tributary streams and freshwater catfish were abundant in billabongs. Following the construction of the Goulburn Weir (completed in 1891) it appears that golden perch and silver perch quickly declined in the mid reaches of the Goulburn River upstream of the weir. Murray cod and Macquarie perch persisted in the main Goulburn River upstream of Goulburn Weir until the mid 1900s but declined following the completion of the enlarged Lake Eildon in 1951 (Lake Eildon originally known as Sugarloaf Reservoir was first constructed in 1929 and subsequently enlarged). Murray cod are still occasionally captured upstream of Goulburn Weir, but as with golden perch are probably stocked fish from the Goulburn Weir. Murray cod and golden perch were also stocked in Lake Eildon and data collected for this project indicates they are still occasionally encountered. The last Macquarie perch captured in the Goulburn River downstream of Goulburn Weir was Upstream of Goulburn Weir, Macquarie perch persist in the Yea River, possibly King Parrot Creek and in Lake Eildon and some upper tributaries. However, the last record for Macquarie perch in the main Goulburn channel upstream of Goulburn Weir is from the early 1970s. Anecdotal information indicates trout cod were widespread in the Goulburn catchment (Cadwallader and Gooley 1984, Trueman 2007). In the 1920s a number of cod and also Macquarie perch were translocated from the Goulburn River around Cathkin and from the Seven Creeks downstream of Gooram Falls to upstream of Gooram Falls (Cadwallader 1979). This translocated population of cod (which turned out to be trout cod) and Macquarie perch persist in Seven Creeks; the trout cod population being, until relatively recently, one of only two selfsustaining populations remaining in the Murray-Darling Basin. The other long-term self-sustaining population is in the Murray River downstream of Yarrawonga and relatively recently extensive stocking in the lower Goulburn River appears to have resulted in the successful establishment of a new breeding population (Koster et al. 2004). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 62

64 There is little information regarding the historical distribution and abundance of small native fish in the Goulburn catchment. Cadwallader (1979) provides one of the earliest and most comprehensive studies of the fish community composition and distribution, but this is limited to Seven Creeks in the mid 1970s. In this system mountain galaxias were the most abundant species and widely distributed through middle and headwater reaches. River blackfish were also abundant and their distribution extended in to lowland reaches. Southern pygmy perch were also relatively abundant, although their distribution was restricted. More recently, a comprehensive survey of the lower Goulburn River, downstream of Goulburn Weir, reported Murray-Darling rainbowfish and Australian smelt dominated the catch, Murray cod were also present in relatively high abundance (Koster et al. 2004). Of note in the Goulburn catchment is the presence of small isolated populations of the endangered barred galaxias. Approximately 20 known populations exist in headwater streams that are isolated from trout (Lintermans 2007). Recent surveys indicate a potential improvement in the status of large bodied native fish in some parts of the Goulburn catchment (Koster et al. 2004). Downstream of Goulburn Weir Murray cod and golden perch were more abundant in than they were in and the abundance of alien species, particularly goldfish and redfin perch declined. Macquarie perch were not recorded in the later surveys but silver perch and trout cod were. CPUE (fish per hour) n Figure 6-13 Comparison in abundance (fish caught per hour) in the lower Goulburn River between 1982/84 and 2004/05 (data source: Koster et al. 2004). Across the basin the Sustainable Rivers Audit recently recorded 14 of a predicted 25 native species, which contributed 43% of average fish abundance and 37% of average biomass per site (MDBC 2007). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 63

65 Campaspe River Twenty-six fish species have been recorded from the Campaspe River; 16 native and 10 alien (Table 6.9). Flat-headed gudgeon is the most common native species, found in 37.1 % of the surveys and across 33.2 % of sites. Golden perch and Australian smelt were also recorded in a relatively high number of survey and sites, while Macquarie perch, mountain galaxias, Murray cod and trout cod were recorded in relatively few surveys. Redfin perch was the most abundant alien species being recorded in over 50% of the surveys and across 66.3% of the sites. Brown trout, carp and goldfish were also commonly recorded. Across the catchment golden perch, carp gudgeon and Murray cod preferred lowland sites whereas mountain galaxias, Macquarie perch, trout cod and southern pygmy perch tended to favour slopes and upland sites (Figure 6-14). Of the alien species carp preferred lowland sites, redfin perch were distributed across all zones as were brown trout, although the later tended to favour slopes and upland sites. n Table 6.9 Species present as a percentage of all surveys and all sites sampled in the Campaspe River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Common Galaxias Flat-headed Galaxias Flat-headed Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Pygmy Perch Spotted Galaxias Trout Cod Alien Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 64

66 Oriental Weatherloach Rainbow Trout Redfin perch Roach Tench Total surveys / sites sampled % sites surveyed Electrofishing Lowland Slopes Upland 0 Australian Smelt Carp Gudgeons Flatheaded Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Spotted Galaxias Trout Cod Brown Trout Carp Goldfish Goldfish X Carp Mosquitofish Redfin Roach Tench n % sites surveyed Australian Smelt Bony Herring Common Galaxias Carp Gudgeons Figure 6-14 Distribution of fish across the Campaspe River Basin fish species at % of sites surveyed using netting and electrofishing techniques. Netting Lowland Flatheaded Galaxias Flatheaded Gudgeon Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Silver Perch Southern Pygmy Perch Spotted Galaxias Brown Trout Carp Goldfish Goldfish X Carp Mosquitofish Oriental Weatherloach Rainbow Trout Redfin Roach Tench Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 65 Slopes Upland

67 Anecdotal information indicates that the Campaspe River supported Murray cod, Macquarie perch and trout cod throughout the lower reaches and upstream to the Coliban River (Cadwallader 1981, Cadwallader and Gooley 1984). Golden perch were also present in the lower and mid reaches of the system (Brumley 1987). Unpublished information collated by Trueman (2007) suggests that in the early 1900s Murray cod and Macquarie perch were present in good numbers, although they became scare by the mid 1900s. Golden perch were also widespread, although perhaps not in the same abundance as the former. In more recent years surveys conducted in the lower Campaspe, downstream of Lake Epalock, from 1995 to 2003 indicate a depauperate native fish community (Humphries et al. 2008). Of the 10 native species recorded by the authors only 3 were considered to have self-sustaining populations (Australian smelt, carp gudgeons and flat-headed gudgeon), the remaining species were either itinerants (e.g. silver perch, Macquarie perch, flat-headed galaxias, spotted galaxias and mountain galaxias) or were sustained by stocking (Murray cod and golden perch have been extensively stocked in the catchment but there is no evidence of successful recruitment (Humphries et al. 2002)). Although native fish contributed over half the total number of fish recorded in the seven year period they contributed only about 1/3 the total biomass. Similarly, surveys in 2006 in the lower Campaspe between Campaspe Weir and Echuca Weir found native fish represented around 50% of total abundance but less than 25% of total biomass (SKM 2007c). In the upper Campaspe, above Lake Eppalock, native fish populations are similarly depauperate. A survey in 2004 near Kyneton recorded just two native species (mountain galaxias and flat-headed gudgeon) and four alien species (tench, redfin perch, goldfish and eastern gambusia) (Pormorin 2005). In this survey native fish represented 13% of the total catch and just 0.6% of the total biomass. Elsewhere in the catchment southern pygmy perch and possibly Australian smelt still occur, however river blackfish have not been recorded since Trout cod, Murray cod and Macquarie perch were stocked in Campaspe River in and upstream of Lake Eppalock in the early 1990s. Macquarie perch were also stocked in the Upper Coliban Reservoir around the same time. There have been occasional occurrences of these species in fish surveys through to the late 1990s but their current status is unknown and without continued stocking are unlikely to sustain a presence (McGuckin and Doeg 2001). Overall, the regulation of river flows downstream of Lake Eppalock (Humphries et al. 2008) and the widespread presence of alien species, impact of barriers to fish passage and loss of habitat (McGuckin and Doeg 2001) have contributed to a significant decline in the abundance and distribution of native species in the Campapse River catchment. Loddon River From 541 fish surveys carried out in the Loddon River Basin, 20 native and 11 alien fish species have been recorded (Table 6.10). Golden perch was the most widespread native species being Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 66

68 present in 17.9 % of surveys and at 25.9 % of sites sampled. Australian smelt, bony herring, Murray cod, and river blackfish have also occurred relatively frequently in surveys and across sites. The remaining native fish have scattered distributions, being recorded in less than 10% of surveys or sites. Of the alien species redfin perch was the most widespread, being recorded in 50% of surveys and at 60.2% of the sites. Brown trout, carp, goldfish and tench were also widespread. n Table 6.10 Species present as a percentage of all surveys and all sites sampled in the Loddon River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Common Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Long-finned Eel? Macquarie Perch Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish River Blackfish Short-finned Eel? Silver Perch Southern Pygmy Perch Spotted Galaxias Un-specked Hardyhead Alien Brown Trout Carp Goldfish Goldfish X Carp Eastern gambusia Oriental Weatherloach Quinnat Salmon Rainbow Trout Redfin perch Roach Tench Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 67

69 Total surveys / sites sampled Only two zones are present in the Loddon system, slopes and lowlands. Most species have been recorded across the lowland zone, including Australian smelt, bony herring, carp gudgeon, freshwater catfish, Murray cod, Murray-Darling rainbowfish, Murray hardyhead, silver perch and un-specked hardyhead (Figure 6-15). Mountain galaxias and river blackfish were mostly present in the slopes zone. Of the alien species carp were mostly recorded at lowland sites, goldfish and redfin perch are have been recorded across both lowland and slopes sites depending on method while brown trout and tench tend to predominate in slopes sites. % sites surveyed % sites surveyed Australian Smelt Bony Herring Australian Smelt Bony Herring Carp Gudgeons Flatheaded Gudgeon Carp Gudgeons Flatheaded Gudgeon Electrofishing Freshwater Catfish Galaxias sp. Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish Murray Hardyhead River Blackfish Silver Perch Netting Un-specked Hardyhead Lowland Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin Roach Tench Lowland Slopes Freshwater Catfish Galaxias sp. Golden Perch Mountain Galaxias Murray Hardyhead Murray-Darling Rainbowfish River Blackfish Silver Perch Spotted Galaxias Brown Trout Carp Goldfish Mosquitofish Oriental Weatherloach Rainbow Trout Redfin Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 68 Slopes Roach Tench

70 n Figure 6-15 Distribution of fish across the Loddon River Basin fish species at % of sites surveyed using netting and electrofishing techniques There is limited historical data for the Loddon catchment. Some of the earliest data is provided by Langtry for the Kerang Lakes area in 1949 and 1950 (Cadwallader 1977). A number of the lakes form part of the irrigation supply system and hence retain permanent water. Redfin perch were the dominant species in most lakes followed by tench. Murray cod were present in some lakes (e.g. Kow swamp, Reedy Lakes and Lake Charm) but were extremely rare in Lake Boga. Silver perch, bony bream, freshwater catfish and golden perch were also present in some lakes, although not in large numbers. However, it is reported that Lake Boga once produced large quantities of freshwater catfish but that by 1949 they were no longer present in the lake (Cadwallader 1977). Many of the lakes supported extensive weed beds that needed to be cut in order to set nets. Anecdotal information in Trueman (2007) indicate that in the early 1900s the lower Loddon River and associated creeks and anabranches, such as Barr Creek, held good numbers of large Murray cod, golden perch, silver perch, freshwater catfish and blackfish. Macquarie perch were also present throughout the system. It was reported that the water was very clear at the time but later turned muddy around the middle of the 1900s and that this also coincided with a decline in fish numbers. In addition to a natural population, Macquarie perch were translocated to a number of locations in the upper Loddon catchment in the 1930s (Cadwallader 1981). Further stocking occurred in the 1995 in the Newbridge and Laanecoorie areas. However, no Macquarie perch have been recorded in fish surveys in the catchment since Murray cod and golden perch have also been extensively stocked, which sustains their presence in the system (SKM 2007c). A significant value in the Loddon catchment is the continued presence of river blackfish in the catchment. They were once widespread throughout the catchment but have not been recorded in the lower reaches since the 1980s. Current populations appear restricted to upper tributary streams such as Birches Creek and Tullaroop Creek. Murray hardyhead are also present in the Kerang Lakes, specifically Round Lake and North Woorinen Lake (Ellis 2005). Populations from other lakes in the area, including Lake Elizabeth, Golf Course Lakes, Cullens Lake and Lake Tuchewop are now considered extinct due to elevated salinity or from lakes drying out (McGuckin and Doeg 2000, Ellis 2005). Recent surveys in the Loddon River downstream of Newbridge recorded just four native species (Australian smelt, flat-headed gudgeon, golden perch and Murray cod) and four alien species (carp, goldfish, redfin perch and eastern gambusia) (SKM 2007c). Native species contributed about 50% of the total catch but only about 10% of the total abundance. Further surveys in 2008 also Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 69

71 recorded silver perch, carp gudgeons, mountain galaxias and Murray-Darling rainbowfish (SKM 2008). Across the whole catchment, the Sustainable Rivers Audit reported native species represented 58% of the total catch and 25% of the total biomass; only 10 of the expected 22 native species were recorded (MDBC 2006). Avoca River There is very limited data from the Avoca River basin with only 81 surveys from 55 sites represented in the data collected for the current project. From these surveys 15 native and 7 alien species have been recorded from the catchment (Table 6.11). River blackfish were recorded in 54% of surveys and at 33% of the sites. Flat-headed gudgeon and mountain galaxias were also relatively widespread. Redfin perch was the most dominant alien species recorded in 94% of the surveys and at 67% of sites. Brown trout, carp and goldfish were also frequently encountered in surveys and across sites. n Table 6.11 Species present as a percentage of all surveys and all sites sampled in the Avoca River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Carp Gudgeon Common Galaxias Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch? 1 2 Southern Pygmy Perch Un-specked Hardyhead Alien Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Tench Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 70

72 Total surveys / sites sampled River blackfish and mountain galaxias were recorded predominantly in the slopes zone (Figure 6-16). Carp gudgeon, flat-headed galaxias, freshwater catfish, Macquarie perch, Murray cod, Murray-Darling rainbowfish, silver perch and un-specked hardyhead have only been recorded from lowland sites. Of the alien species, redfin perch are present throughout both lowland and slopes zones, carp where predominantly recorded in lowland sites and trout in the slopes zone lowland Slopes % sites surveyed n Figure 6-16 Distribution of fish across the Avoca River Basin fish species at % of sites surveyed using netting and electrofishing techniques (note insufficient surveys to separate methods). The earliest records for the Avoca catchment are for Macquarie perch and Murray cod in The Avoca River was considered outside the natural range of Macquarie perch by Cadwallader (Cadwallader 1981), however, they were translocated to the Avoca River in 1927 (Cadwallader 1981) and were occasionally encountered in the Murray River around Swan Hill and in the Loddon River in the late 1960s and early 1970s. The 1970 record for Macquarie perch may be a missidentification or it may represent one of the last records of this species in the middle Murray region and its tributaries. Murray cod were translocated to the Avoca River in 1972 but have not been recorded in surveys since 1981 and it is unclear whether they are still present in the system. Golden perch have also been stocked in the Avoca River (Brumley 1987) and have been occasionally recorded throughout the 1990s. Recent surveys in the Avoca catchment recorded flat-headed gudgeon, mountain galaxias and river blackfish (SKM 2007c). Flat-headed gudgeon and river blackfish were relatively widespread across six sites surveyed but mountain galaxias were restricted to just one location. Alien species Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 71

73 recorded were carp, redfin perch and eastern gambusia. As with adjacent river basins, native species represented around 50% of the total number of fish captured but only around 5% of the total biomass (SKM 2007c). The Sustainable Rivers Audit has also recently surveyed the Avoca catchment and recorded 6 native species out of an expected 16 and 4 alien species (MDBC 2007). Native species comprised 68% of the total catch but only 8% of the total biomass. 6.2 Murrumbidgee Region The Murrumbidgee River rises in southern NSW on the western slopes of the Great Dividing range. It flows in a north westerly direction through the ACT before heading west to discharge into the Murray River downstream of Swan Hill. The Lachlan River lies to the north of the Murrumbidgee and flows in a westerly and then south westerly direction across south central NSW and the Great Cumbung Swamp to discharge into the Murrumbidgee not far upstream of the junction with the Murray River Murrumbidgee River Basin Nearly 600 surveys across over 300 sites have been recorded in the Murrumbidgee catchment (Table 6.12). Twenty three native and 8 alien species have been recorded. Australian smelt, carp gudgeon, golden perch, mountain galaxias and Murray cod were relatively widespread, being sampled in up to 19% of surveys and at up to 20% of sites. The remaining native species have been recorded in less than 10% of surveys and sites. Of the alien fish species, carp were most widespread, recorded in 36% of the surveys and at 28% of the sites. Rainbow and brown trout, redfin perch, goldfish and eastern gambusia were also recorded in a relatively large number of surveys and sites. Figure 6-17 shows the distribution of species based on presence at percentage of sites surveyed using either netting or electrofishing techniques. Bony herring and Murray hardyhead were found exclusively in the lowland habitats. Whereas Australian smelt, silver perch, Murray cod, carp gudgeon and un-specked hardyhead where found in all zones except for the montane. Macquarie perch, mountain galaxias and two-spined blackfish were not found in the lowland areas, preferring upland and montane zones. Alien species were recorded across all zones; in particular, carp were recorded at 90% of lowland sites, over 60% of slope and upland sites and 20% of montane sites. Redfin perch tended to occur in lowland, slopes and upland zones sites whereas trout were more likely to be present in upland and montane zones. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 72

74 n Table 6.12 Species present as a percentage of all surveys and all sites sampled in the Murrumbidgee River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Climbing Galaxias Dwarf Flat-headed Gudgeon Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive Perchlet River Blackfish Silver Perch Southern Purple-spotted Gudgeon Southern Pygmy Perch Spangled Perch Trout Cod Two-spined Blackfish Un-specked Hardyhead Alien Brown Trout Carp Goldfish Eastern gambusia Oriental Weatherloach Rainbow Trout Redfin perch Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 73

75 Electrofishing % sites surveyed Low land Slopes Upland Montane 0 Australian Smelt Bony Herring Carp Gudgeons Flatheaded Gudgeon Flatheaded Gudgeon sp. Un-specked Hardyhead Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish River Blackfish Silver Perch Spangled Perch Trout Cod Two-spined Blackfish Brown Trout Carp Goldfish Mosquitofish Oriental Weatherloach Rainbow Trout Redfin Perch 70 Netting % sites surveyed Lowland Slopes Upland 10 0 n Figure 6-17 Distribution of fish across the Murrumbidgee River Basin fish species at % of sites surveyed using netting and electrofishing techniques. Early records for the Murrumbidgee catchment are predominantly from the middle and lower parts of the catchments and indicate a diverse native fish fauna was present. Murray cod, silver perch, freshwater catfish and golden perch were the dominant large bodied species. Trout cod and Macquarie perch were also well represented in early surveys. Small bodied native fish included southern pygmy perch, Australian smelt, olive perchlet, carp gudgeon, southern purple-spotted gudgeon, flat-headed gudgeon, un-specked hardyhead and Murray hardyhead. In upper reaches Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 74

76 Macquarie perch, mountain galaxias and blackfish were well represented as were trout cod and the occasional Murray cod and silver perch (Trueman unpublished data). Alien fish first appeared in the records in the early 1900s; goldfish in 1910 and rainbow trout in Carp and redfin perch were recorded in 1949, although redfin perch were likely present in the system earlier than that, being described by Langtry as well established in 1949 (Cadwallader 1977). In the mid 1900s Langtry reported that stocks of commercial species (Murray cod, golden perch and silver perch) remained high in the lower Murrumbidgee, at least compared to the Murray system, but there were claims that depletion of fish stocks had occurred through the early 1900s (Cadwallader 1977). In particular, anecdotal evidence from commercial fishers reported in Cadwallader (1977) suggested that following the construction of dams and weirs on the Murrumbidgee in the early 1900s the fishing declined because the number of billabongs was reduced due to river regulation. Anecdotal information collected by Trueman (unpublished) suggests that by the mid 1900s most large bodied native fish were becoming scare in the Murrumbidgee system, particularly trout cod, Macquarie perch and freshwater catfish. Data compiled by Llewellyn (1983) on the distribution of fish in NSW showed that between 1960 and native and 7 alien species had been recorded in the Murrumbidgee catchment. In 1996 only 9 native species and 6 alien species were recorded from 12 sites as part of the NSW Rivers Survey (Harris and Gehrke 1997). More recently, Gilligan (2005b) recorded 13 native species and 1 species complex (Hypseleotris sp.) and 7 alien species across 52 sites (including wetland sites, which were not sampled in the NSW Rivers Survey) in surveys conducted in This represented 62% of the native species known to have previously occurred in the system and 64% of the alien species previously recorded. On the basis of the survey methods Gilligan (2005b) concluded that the Murrumbidgee catchment has suffered the loss of and / or very low abundance of 8 of the 21 species known to previously occur. Furthermore, across the catchment native species contributed around 40% of total abundance but only around 20% of total biomass. Although there was some variability across zones with native species representing around 80% of total abundance and 30% of total biomass in lowland sites, upland sites had the lowest proportion of native abundance (~20%) and slopes sites had the lowest proportion of native biomass (~5%) (Gilligan 2005b). Carp where the most widespread species and second most numerous species recorded in the catchment and contributed 87% of the total biomass. Eastern gambusia (most numerous) and Australian smelt (third most numerous) contributed just 0.1% of total biomass. Gilligan (2005b) also assessed trends in species abundance from 1994 to He found that in general very little change in population structure occurred over the ten year period, although there was a significant increase in species richness across the whole catchment, a non-significant increase in total abundance and a non-significant decrease in total biomass. The increase in species Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 75

77 richness could be a result of the spread of alien species or a recovery and spread in the distribution of rare native species. There was a significant increase in the abundance of carp gudgeons and redfin perch across the catchment while there was a non-significant decline in carp abundance in the lowland zone but an increase in upland and montane zones, indicating a potential continued expansion into higher elevation areas of the basin. There were non-significant declines in abundance of un-specked hardyhead, mountain galaxias, golden perch, Macquarie perch and bony herring. The relatively stable population structure detected over the ten year period suggests that native and alien populations may have reached a new equilibrium and provides further evidence that initial declines in native fish populations occurred prior to the mid 1900s (Reid et al. 1997). In the upper Murrumbidgee catchment a significant amount of survey and research has been undertaken in recent years examining the status of native fish such as Macquarie perch, mountain galaxias and blackfish (Lintermans 2000, 2002, 2006). Macquarie perch are currently known from a number of locations in the upper Murrumbidgee catchment, including sections of the Murrumbidgee, Queanbeyan, Cottor, Molongolo and Paddys Rivers (Lintermans 2002). A long term monitoring program targeting Macquarie perch in the Murrumbidgee River in the ACT from 1979 to 2000 documented a substantial decline in Macquarie perch over an approximate 40 km reach from Retallacks Hole upstream to Kambah Pool (Lintermans 2002). From 1979 to individuals were captured from a total of 122 net/nights of sampling, however, from 1985 to 2000 just 2 individuals were recorded in 146 net/nights of sampling (Figure 6-18). fish per net night n Figure 6-18 Captures of Macquarie perch, standardised to fish per net night, for three sites in the Murrumbidgee River (ACT) (data source Lintermans 2002). Further evidence of decline in native species in the area comes from data collected from a permanent fish trap on the Murrumbidgee River at Casuarina Sands between 1980 and 1991 (Lintermans 2002). Over the 11-year monitoring period there was over an order of magnitude Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 76

78 decrease in the numbers of Macquarie perch and Murray cod captured when standardised to fish per trap day (Figure 6-19). Conversely, there was a nearly 2-order of magnitude increase in carp captured over the 11 sample years and a 2-order of magnitude increase in redfin perch capture over just 6 samples years from when they first appeared in Golden perch and silver perch were also captured, but only in 3 and 4 of the 11 sampling years respectively and with variable results. Number of fish per trap day Murray cod golden perch silver perch Macquarie perch carp redfin perch n Figure 6-19 Summary of fish captured per trap day in the Murrumbidgee River at Casuarina Sands between 1980 and 1991 (data source Lintermans 2002). Despite the overall decline in abundance in native fish in the Murrumbidgee catchment since the early 1900s, there are some isolated successes. Trout cod were once considered widespread in the Murrumbidgee catchment but the last wild fish were recorded in the early 1970s (Lintermans 2002, Gilligan 2005b). Extensive stocking has occurred since the mid 1990s in an effort to re-establish breeding populations and surveys in 2004 appear to provide evidence that stocking has been successful at establishing a recruiting population in the Murrumbidgee River in the Narrandera area (Gilligan 2005b). In the upper Murrumbidgee catchment, Macquarie perch were translocated from Googong Reservoir to the Queanbeyan River upstream of Curleys Falls in 1980, subsequent surveys in 1996/97 revealed an actively recruiting population established from the initial translocation, however, the reservoir population appears to have disappeared (Lintermans 2006). Also in the upper Murrumbidgee catchment, the eradication of rainbow trout from a section of Lees Creek has resulted in the recolonisation of that section of stream by mountain galaxias (Lintermans 2000) Lachlan River Basin Data for over 250 surveys at 186 sites have been collated for the Lachlan River catchment; 19 native and 7 alien species have been recorded (Table 6.13). Carp gudgeons and Australian smelt were the most widespread native species, being present in 28% and 22% of surveys respectively and across 32% and 20% of sites respectively. Flat-headed gudgeons, bony herring golden perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 77

79 and mountain galaxias were relatively widespread, being present in 10% to 20% of surveys and across sites. The remaining native species occurred less frequently and some species have not been sampled for some time particularly olive perchlet (1960), short-headed lamprey (1961) and Murray hardyhead (1972). Alien species were well represented; carp was present in 42% of the surveys and across 36% of sites. Goldfish, eastern gambusia and redfin perch were also frequently recorded in surveys and across sites. n Table 6.13 Species present as a percentage of all surveys and all sites sampled in the Lachlan River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Flat-headed Gudgeon Flat-headed Gudgeon sp Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive Perchlet River Blackfish Short-headed Lamprey Silver Perch Southern Pygmy Perch Two-spined Blackfish Un-specked Hardyhead Aliens Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch < Tench Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 78

80 Figure 6-20 shows the distribution of fish across lowland, slopes, upland and montane zones in the Lachlan catchment separated by electrofishing and netting survey methods. Mountain galaxias favoured the montane areas but were also present in upland and slope zones. Australian smelt and bony herring tended to favour sites in the lowland zone. Carp gudgeons, golden perch and Murray cod were evenly distributed across lowland, slope and upland zones. Alien species were relatively evenly distributed across all zones, although carp, goldfish and redfin perch favoured sites in the lowland zone, while eastern gambusia and trout favoured sites in the slopes, upland and montane zones. % sites surveyed Electrofishing Lowland Slopes Upland Montane Australian Smelt Bony Herring Carp Gudgeons Flatheaded Gudgeon Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin % of sites surveyed Netting Lowland Slopes Upland Montane Australian Smelt Bony Herring Carp Gudgeons Flatheaded Gudgeon Flatheaded Gudgeon sp. Un-specked Hardyhead Freshwater Catfish Golden Perch Macquarie Perch Mountain Galaxias Murray Cod Murray Hardyhead River Blackfish Silver Perch Southern Pygmy Perch Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin n Figure 6-20 Distribution of fish across the Lachlan River Basin fish species at % of sites surveyed using netting and electrofishing techniques Lachlan River. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 79

81 Anecdotal evidence from early explorers indicate Murray cod, silver perch and freshwater catfish were prevalent in the Lachlan basin prior to 1900 (Scott 2005). A record for redfin perch prior to 1900 is also present in collated data. Langtry provides one of the earliest descriptions of the Lachlan River fishery in the Hillston area around the mid 1900s (Cadwallader 1977). He reported that golden perch provided the bulk of the professional fisherman s catch, although Murray cod, silver perch and freshwater catfish also contributed to the catch and lampreys were occasionally taken. However, at the time, trout cod, bony herring and Macquarie perch were absent. Of the alien species redfin perch were present and were increasing in numbers, carp and tench were also recorded. Langtry also mentions the presence of large schools of Australian smelt but does not report on other small native species or on the fish community of the upper parts of the Lachlan catchment. Anecdotal information compiled by Trueman (2007) provides additional information on the upper Lachlan catchment, including the presence of trout cod and Macquarie perch, particularly in the Lachlan River around Reids Flat and the Abercrombie River, both of which are upstream of Wyangala Dam. Blackfish, Murray cod, freshwater catfish and golden perch were also reported in the Reids Flat area. As with catchments further south, anecdotal information suggests a decline in fish numbers in the mid 1900s, although it would also appear that fish numbers remained high into the 1970s and 80s in some locations, particularly upstream of Wyangala Dam (Trueman 2007). Oral histories suggest bushfires, floods and the introduction of trout in the 1950s coincided with declines in native fish numbers, particularly blackfish, trout cod and Macquarie perch in the upper Lachlan, although the Abercrombie River may have fared a little better where Macquarie perch are still present in low numbers in at least 2 locations upstream of Lake Wyangala based on data collected in the NSW Rivers Survey (Schiller et al. 1997) and the Sustainable Rivers Audit fish theme pilot survey (MDBC 2004). Small native species thought to have once been widespread, although in low abundance in the lower Lachlan catchment included olive perchlet, southern purple-spotted gudgeon and Murray- Darling rainbowfish (Llewellyn 1983, Fisheries Scientific Committee 2005, Lintermans 2007). However, data collected for the current project show olive perchlet were only recorded in 1920 and 1960, southern purple-spotted gudgeon have not been recorded and Murray-Darling rainbowfish have been recorded in 1950 and However, a number of other small native species recently recorded include un-specked hardyhead, dwarf flat-headed gudgeon, flat-headed gudgeon and southern pygmy perch. As with other southern basins only around 50% of the 20 native species predicted to occur in the catchment were detected in the Sustainable Rivers Audit (MDBC 2004). This is a slight improvement on the number of native species detected in the NSW River survey (8) but slightly Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 80

82 less than the 11 reported present in the catchment from (Llewellyn 1983). However, native species made up a greater proportion of the total abundance (~68%) compared to most other southern basins although native biomass was less than 20% of total biomass per site (MDBC 2004). 6.3 Darling Region The Darling region comprises the Darling River and tributaries rising in northern NSW and southern QLD. The Darling itself forms at the junction of the Culgoa and Barwon Rivers in north central NSW and flows in a south westerly direction to join the Murray River at Wentworth Darling River Basin Eleven native and 4 alien species have been recorded from 103 surveys across 73 sites in the Darling River basin (Table 6.14). Bony herring were the most widespread native species, being present at in 80% of surveys and across 73 % of sites. Golden perch, carp gudgeons, Australian smelt and Murray cod were also widely distributed. Species present in less than 20% of surveys or sites included Murray-Darling rainbowfish, freshwater catfish, silver perch, un-specked hardyhead and spangled perch. Carp was the most prevalent alien species, being present in 71% of surveys and across 60% of sites. Goldfish and eastern gambusia were also widespread, while redfin perch were encountered at relatively few sites and have not been sampled since n Table 6.14 Species present as a percentage of all surveys and all sites sampled in the Darling River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Flat-headed Gudgeon Freshwater Catfish Golden Perch Murray Cod Murray-Darling Rainbowfish Silver Perch Spangled Perch Un-specked Hardyhead Alien Carp Goldfish Eastern gambusia Redfin perch Total surveys / sites sampled Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 81

83 For the purposes of zonation the Darling River is split in two, the lower zone is from Pooncarie to the Murray River and includes the Great-Darling Anabranch. The middle zone is upstream of Pooncarie to Bourke. There was some variation in distribution across zones depending on survey method (Figure 6-21), however, in general bony herring were recorded at a most sites across both middle and lower sites. Australian smelt, carp gudgeons and Murray-Darling rainbowfish were also distributed across both zones, the later at only about 20% of sites in each zone. Golden perch and Murray cod tended to favour lower sites, flat-headed gudgeon were only recorded at a few lower sites from electrofishing. Silver perch favoured sites in the middle zone and spangled perch were only recorded in the middle zone from electrofishing surveys. Of the alien species, carp were present at most sites across both zones, goldfish were also evenly distributed across both zones; eastern gambusia appeared to favour sites in the middle zone. % sites surveyed Electrofishing Middle Lower % sites surveyed Netting Middle Lower n Figure 6-21 Distribution of fish across the Darling River Basin fish species at % of sites surveyed using netting and electrofishing techniques. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 82

84 Early data (c1900) collated for the Darling River indicate the presence of freshwater catfish, silver perch, spangled perch and bony herring, although early explorer and indigenous anecdotes indicate the presence of Murray cod and golden perch as well (Dargin 1976, Scott 2005). However, most data collated for the project is post 1970 and effort data is only available for Sustainable Rivers Audit surveys conducted in 2004/2005, hence it is not possible to quantitatively assess historic trends in abundance. As indicated in earlier sections, anecdotal evidence from early explorers, evidence of the utilisation of native fisheries by indigenous people and commercial catch information from the late 1800s and early 1900s indicate the Darling River supported a very abundant native fish fauna. Data indicates the native fish diversity is relatively low compared to southern catchments, however, native fish are recorded at a greater proportion of sites than in southern catchments and there are fewer alien species, although what are present are also widespread. Llewellyn (1983) reported 5 native species (silver perch, spangled perch, golden perch, bony herring and Australian smelt) and 4 alien species (carp, goldfish, eastern gambusia and redfin perch) from the Darling catchment between 1960 and The NSW River survey recorded an additional 4 native species (un-specked hardyhead, Murray cod, Murray-Darling rainbowfish and western carp gudgeon) but didn t record redfin perch or eastern gambusia (Harris and Gehrke 1997). Gilligan (2005a) recorded 6 native and 3 alien species in 2004 in the Darling River. Native species contributed greater than 80% of the total abundance but only around 40% of the total biomass, which was dominated by carp. The Sustainable Rivers Audit surveys in 2005 recorded 9 of a potential 21 native species although the natives present contributed on average 89% of total abundance and 69% of total biomass per site (MDBC 2006). The three later surveys described above used relatively similar survey techniques and demonstrate the variability in results that can be experienced over short time frames, and hence difficulty in detecting long term trends. Gilligan (2005a) assessed trends in fish community composition between and He found variable results with species richness and abundance increasing at some sites but decreasing at others. Overall, there was a general increase in the abundance of native species, but particularly carp-gudgeons and Australian smelt and Murray cod at some sites, carp also increased in abundance in the Darling River. There was a general decrease in the abundance of golden perch. However, overall he concluded that there has been little change in the fish community structure in recent years and that it remains relatively stable compared to the much larger changes that have occurred since the early 1900s based on analysis of commercial catch data (See Section 5). Gilligan (2005a) suggested that the main reason for the low number of native species compared to predicted is because several of the predicated or historically present species are now considered extinct in the region (e.g. southern purple-spotted gudgeon, olive perchlet, southern pygmy perch, flat-headed galaxias, trout cod and Macquarie perch). In addition, a number of species are considered vagrant, or only occasionally encountered so are difficult to detect because of their low Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 83

85 abundance, patchy distribution and only occasional presence (e.g. tupong, short-headed lamprey and Hyrtl s tandan). Compared to the Murray River and its upstream tributaries, the Darling River may support fewer native species but they tend to contribute a greater proportion to the total abundance and a greater proportion of the total biomass Northern NSW tributaries (Macquarie, Castlereagh, Namoi, Gwydir basins) Northern NSW tributaries of the Darling River all rise on west slope of the central and northern parts of the Great Dividing Rang in NSW, including the New England Tablelands. They flow in a north to westerly direction to form the Barwon River, which ultimately becomes the Darling upstream of Bourke. Macquarie Bogan Basin The Macquarie River rises on the western slopes of the Great Dividing Range and flows in a general north westerly direction, through the Macquarie Marshes and into the Barwon River near Brewarrina. The basin also includes the Bogan River to the south which enters the Darling River near Bourke. Seventeen native and 7 alien fish species were recorded in the Macquarie Bogan catchment data collated for the current (Table 6.15). Carp gudgeons were the most widespread natives, being present in 33% of surveys and across 27% sites. Australian smelt, bony herring, golden perch and mountain galaxias were recorded in 20% to 24% of all surveys. Murray cod and freshwater catfish were present across around 10% of sites, which is better than for other catchments further south. The remaining native fish species have occurred in fewer surveys and sites although most have been recorded in recent years, except flat-headed galaxias (1993), olive perchlet in the Bogan River in 1991 and an historical record of trout cod from Of the alien species, carp, goldfish and eastern gambusia were widespread, redfin perch were also present. Salmonids have been recorded at less than 5% of sites and only rainbow trout has been recorded in recent years. n Table 6.15 Species present as a percentage of all surveys and all sites sampled in the Macquarie Bogan catchment including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Flat-headed Galaxias Flat-headed Gudgeon Freshwater Catfish Golden Perch Mountain Galaxias Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 84

86 Murray Cod Murray-Darling Rainbowfish Olive Perchlet River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Trout Cod Un-specked Hardyhead Alien Brook Char Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Total surveys / sites sampled Figure 6-22 shows the distribution of fish across lowland, slopes and upland zones separated by electrofishing and netting survey methods. Although generally native fish appeared in most environments there were some preferences. Bony herring, carp gudgeons, golden perch, Murray cod and Murray-Darling rainbowfish tended to be found in lowland or slopes zones. Freshwater catfish were, Australian smelt, mountain galaxias flat-headed gudgeon, flat-headed galaxias and river blackfish tended to occur in slopes and upland zones. The majority of alien species were found throughout most zones, although carp and goldfish tended to be prevalent in the lowland and slopes zone while trout and redfin were present in the slopes and upland zone. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 85

87 % sites surveyed Electrofishing Australian Smelt Bony Herring Carp Gudgeons Flatheaded Galaxias Flatheaded Gudgeon Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Southern Purple-spotted Gudgeon Spangled Perch Brown Trout Carp Lowland Slopes Upland Goldfish Mosquitofish Rainbow Trout Redfin 70 Netting 60 Lowland Slopes % sites surveyed Upland 10 0 Australian Smelt Bony Herring Carp Gudgeons Flatheaded Gudgeon Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Spangled Perch Un-specked Hardyhead Brown Trout Carp Goldfish Mosquitofish Rainbow Trout Redfin n Figure 6-22 Distribution of fish across the Macquarie River Basin fish species at % of sites surveyed using netting and electrofishing techniques There is no suitable data to quantify historical trends in fish abundance in the catchment. Early explorer records documented a large abundance of native fish, namely Murray cod, silver perch and freshwater catfish in the basin (See Section 4). Anecdotal evidence from the early 1900s also indicates the presence of trout cod and Macquarie perch in the Bathurst region (Trueman, Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 86

88 unpublished data). Tout cod were also stocked in the Macquarie River in the early 1990s (Faragher et al. 1993) but have not been recorded in subsequent surveys. The current status of Macquarie perch and trout cod in the catchment is unknown. Southern purple-spotted gudgeon were recorded at three location c1900 but were not recorded again until 2005, indicating a patchy but persistent distribution in the catchment. Surveys in the Macquarie Marshes in the mid 1990s recorded a high abundance of bony herring and carp and the absence of silver perch and freshwater catfish, which had been previously recorded in the area (Swales and Curran 1995). Freshwater catfish have been recorded in the upper Macquarie catchment post 1995 but not in the Bogan catchment. Silver perch have only been recorded on a few occasions since 1990 (in 1999 and 2005) in the lower reaches of the Macquarie River but not in the upper reaches or the Bogan River, where they have previously been recorded in the 1960s and 70s (Llewellyn 1983). The Sustainable Rivers Audit recently recorded 10 native species from a predicted 18, native species contributed 21% to total abundance and 38% to total biomass (MDBC 2007). Castlereagh River The Castlereagh River is a relatively small catchment that rises in the Warrumbungle Ranges and flows north west to join the Macquarie River just upstream of its confluence with the Barwon River. It is bordered to the south by the Macquarie basin and to the north by the Namoi. Very few survey records were collated for the Castlereagh River basin (36 sites in total). Nine native and 3 alien species were recorded (Table 6.16). Carp gudgeons were the most widespread native species (62% of sites) followed by Australian smelt (45% of sites). The remaining native species were recorded at less than 10% of sites, with golden perch, Murray-Darling rainbowfish and un-specked hardyhead not having been recorded since the mid 1970s. Eastern gambusia were the most widespread alien (47% of sites) while carp and goldfish were found at 17 and 11% of sites respectively. n Table 6.16 Species present as a percentage of all surveys and all sites sampled in the Castlereagh River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Golden Perch Mountain Galaxias Murray-Darling Rainbowfish Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 87

89 River Blackfish Spangled Perch Un-specked Hardyhead Alien Carp Goldfish Eastern gambusia Total surveys / sites sampled The small number of surveys meant insufficient data was available to consider fish distribution across zones by sample method. Surveys from had recorded Australian smelt, carp gudgeons, bony herring, river blackfish goldfish and eastern gambusia (Llewellyn 1983). Golden perch, Murray-Darling rainbowfish and un-specked hardyhead were subsequently detected in the mid 1970s, although they have not been recorded since. In the mid 1990s the NSW River Survey, recorded just two native species, spangled perch and Australian smelt, as well as carp (Harris and Gehrke 1997). Surveys in 2000 recorded mountain galaxias for the first time but overall the native fish community was of low diversity, being dominated by just Australian smelt and carp gudgeons. Data collected for the Sustainable Rivers Audit from the Castlereagh River is yet to become available. Namoi River The Namoi River rises in the Great Dividing Range north of the Castlereagh catchment and flows north west to join the Barwon River near Walgett. The catchment includes the Chaffey and Keepit Dams. Fourteen native and 5 alien species have been recorded in data collated for the Namoi catchment (Table 6.17). Bony herring, carp gudgeons and golden perch were the most frequently encountered native species, occurring in over 35% of surveys. Carp gudgeons in particular were widespread, occurring at 47% of sites. Other widespread species included bony herring, golden perch, freshwater catfish, Australian smelt and spangled perch. Most native species have been recorded recently, except olive perchlet, which has not been recorded since 1910, and Darling River hardyhead, which was last recorded in Carp was the most frequently encountered alien fish, present in 45% of surveys across 34% of sites. Goldfish and eastern gambusia were present in 25% of surveys while the remaining alien species, rainbow and brown trout, were infrequently recorded. n Table 6.17 Species present as a percentage of all surveys and all sites sampled in the Namoi River including year of most recent sample for native species and year of first and last record for alien species. Species First Last % presence % of sites Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 88

90 Native record record in surveys present Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish Olive perchlet River Blackfish Silver Perch Spangled Perch Un-specked Hardyhead Aliens Brown Trout Carp Goldfish Eastern gambusia Rainbow Trout Total surveys / sites sampled Figure 6-23 shows the distribution of fish species across lowland, slopes, upland and montane zones. Most species have been recorded across all zones, although Australian smelt, bony herring, carp gudgeon, Murray-Darling rainbowfish and spangled perch were present at a greater percentage of lowland and slopes sites than upland and montane zones. Conversely, Darling River hardyhead, freshwater catfish, mountain galaxias and river blackfish tended to favour upland and montane zones. Alien species were recorded across all zones, although trout were only recorded in upland and montane zones. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 89

91 % sites surveyed Lowland Slopes Upland Montane 0 Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish Olive perchlet River Blackfish Silver Perch Spangled Perch Un-specked Hardyhead Brown Trout Carp Goldfish Mosquitofish Rainbow Trout n Figure 6-23 Distribution of fish across the Namoi River Basin fish species at % of sites surveyed (note all methods were combined due to low survey numbers). No data is available to quantify historical trends in fish abundance. Records from indicate the presence of 11 native species (Llewellyn 1983), while the NSW River Survey recorded 10 native species (Harris and Gehrke 1997) and overall the native fish fauna of the catchment was considered degraded due to low diversity and abundance (Thoms et al. 1999). More recently the Sustainable Rivers Audit recorded 12 out of a predicted 15 native species, which is second only to the Border Rivers basin for the highest proportion of observed to predicted native species (MDBC 2006, 2007). In addition, native species represented a relatively large proportion of total abundance (63%), although natives only represented 39% of total biomass per site, indicating the native species present in highest abundances are small bodied, such as carp gudgeons, Australian smelt and Murray-Darling rainbowfish. Considerable stocking of golden perch and Murray cod has taken place in the catchment, including in impoundments, which may be helping to maintain stocks of these species. Of note, the Namoi catchment contains the Peel River, from which the holotype of Murray cod was collected by the explorer Thomas Mitchell in 1831 (Rowland 2005). Gwydir River The Gwydir River flows west from the Great Dividing Range. The Copeton Dam (completed in 1976) is located in the upper reaches and regulates flow downstream through several weirs where water is diverted for irrigation (Copeland et al. 2003). The river flows through the Ramsar listed Gwydir Swamp before joining the Barwon River. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 90

92 From the 315 fish surveys conducted in the Gwydir River basin, 14 native and 3 alien species were recorded (Table 6.18). Carp gudgeons were the most widespread native species, having been recorded at 53% of sites. Most other native species were also relatively widespread, including spangled perch, freshwater catfish, bony herring, golden perch and Murray cod. Native species recoded at few sites included Darling River hardyhead, silver perch and southern purple-spotted gudgeon, although these species have been sampled in recent surveys (2005), indicating continued presence in the system. Alien species were also widespread. Eastern gambusia were recorded at 51% of sites, goldfish at 42% of sites and carp at 35% of sites. n Table 6.18 Species present as a percentage of all surveys and all sites sampled in the Gwydir River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Alien Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Total surveys / sites sampled Figure 6-24 shows the distribution of fish across lowland, slopes zones, upland and montane zones by electrofishing and netting survey methods. Most native species were recorded across all zones. The exceptions to this were river blackfish and the mountain galaxias which were restricted to the upland and montane reaches. Likewise Darling River hardyhead and southern purple-spotted gudgeon were only found in the slopes zone. Alien species were also recorded across all zones, although carp was not recorded in the montane zones, whereas rainbow trout were only recorded in Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 91

93 the montane zone. Carp were sampled in 100% of lowlands sites when electrofishing was employed. % sites surveyed Electrofishing Lowland Slopes Upland Montane Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Carp Goldfish Mosquitofish Rainbow Trout Redfin % sites surveyed Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Netting Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Carp Lowland Slopes Upland Montane Goldfish Mosquitofish Rainbow Trout Redfin n Figure 6-24 Distribution of fish across the Gwydir River Basin fish species at % of sites surveyed using netting and electrofishing techniques. There are limited historical records for the Gwydir catchment, most survey data is post 1976, following the construction of Copeton Dam. However, oral histories collated by Copeland et al. (2003) provide an indication of the changes in the native fish community over the past 50 years. Anecdotal evidence suggests an abundant native fish community was present prior to the construction of Copeton Dam and the arrival of carp in the mid 1970s. Following dam construction freshwater catfish decline substantially, as did silver perch. However, regulation of the flow Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 92

94 regime is considered to have improved conditions for Murray cod, which coupled with stocking are thought to have increased in abundance. Based on data collated for the current project, carp appeared in the catchment in 1970 (which concurs with anecdotal evidence), and this is also thought to have coincided with reduced fish abundance (Copeland et al. 2003). Despite the anecdotal evidence of decline, native fish still appear to be widespread throughout the basin, including the presence of species that have virtually disappeared from southern parts of the basin, such as southern purple-spotted gudgeon. There was no difference in the number of native species recorded from with those recorded in the NSW Rivers Survey (10 native species) (Llewellyn 1983, Harris and Gehrke 1997). Data collected for the Sustainable Rivers Audit is as yet unavailable for this catchment Border Rivers basin The Border Rivers basin lies to the north of the Gywdir catchment and straddles the border with Queensland. It includes the MacIntyre, Dumaresque and Severn Rivers which join to form the Barwon River. Data has been collated for over 350 surveys at 180 sites and 15 native and 5 alien species have been recorded (Table 6.19). Of the native species, freshwater catfish was sampled in 65% of surveys across 39% of sites. Carp gudgeons were also widespread, present at 42% of the sites. All other native species were relatively frequently encountered, being present in over 15% of surveys, except for silver perch, river blackfish and olive perchlet, which were recorded at less than 5% of sites. All native species have been recorded since 2002 indicating continued presence in the catchment. Alien species were widespread with eastern gambusia occurring across 51% of the sites, gold fish 38% of sites and carp 22% of sites. Rainbow trout were recorded at just 2% of the sites. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 93

95 n Table 6.19 Species present as a percentage of all surveys and all sites sampled in the Border Rivers including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-Darling Rainbowfish Olive Perchlet River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Aliens Carp Goldfish Eastern gambusia Rainbow Trout Redfin perch Total surveys / sites sampled Figure 6-25 shows the distribution of fish across lowland, slopes, upland and montane zones for all methods combined. Southern purple-spotted gudgeon, olive perchlet, un-specked hardyhead, freshwater catfish, river blackfish, mountain galaxias and Darling River hardyhead all favoured slope, upland and montane sites. Bony herring, golden perch and spangled perch favoured the lowland zone. Murray cod, silver perch and carp gudgeons were distributed across all zones, although silver perch were recorded at only a few sites. Carp favoured lowland sites, while rainbow trout and redfin perch tended to be found in the upper reaches of the basin. Goldfish and eastern gambusia were distributed across all zones. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 94

96 % sites surveyed Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Freshwater Catfish Golden Perch Mountain Galaxias Murray Cod Murray-darling Rainbowfish Olive perchlet River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Carp Lowland Slopes Upland Montane Goldfish Mosquitofish Rainbow Trout Redfin n Figure 6-25 Distribution of fish across the Border Rivers Basin fish species at % of sites surveyed (note all methods combined due to low survey numbers) The majority of data from the Border Rivers is post the mid 1970s, standardised abundance data is only available from surveys conducted in the 2000s, hence it is not possible to quantify historic trends. The only quantitative assessment possible is that provided by the Sustainable Rivers Audit (MDBC 2006), which recorded 13 of a predicted 15 native species (silver perch and spangled perch were not recorded in the SRA but have been recorded as recently as 2002). On average native species represented 63% of the abundance and 60% of the biomass at each site, which suggests that the declines in native fish diversity and abundance experienced in southern catchment is not as pronounced in some northern catchments Queensland tributaries (Paroo, Warrago, Condamine basins) Paroo and Warrago Basins The Paroo and Warrago Rivers rise in semi arid zones in south western and central western Queensland and flow south towards the Darling River. Flow is intermittent and in the case of the Paroo, only reaches the Darling River in times of flood (Boys et al. 2005). Limited surveys have been undertaken in the Paroo and Warrago catchments; 34 in the Paroo and 10 in the Warrago. In the Paroo River basin 10 native and 3 alien species have been recorded (Table 6.20). Bony herring and spangled perch were the most widespread, being recorded from 65% and 55% of sites respectively. Golden perch and Murray-Darling rainbowfish were also relatively widespread, as were Australian smelt, silver perch and Hyrtl s tandan. Freshwater catfish have previously been recorded at a few locations in the Paroo River but has been absent since the mid 1970s. There is also an historic record of southern purple-spotted gudgeon (c 1900). Of the Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 95

97 alien species goldfish were recorded at 39% of sites, eastern gambusia at 29% of sites and carp at 19% of sites. n Table 6.20 Species present as a percentage of all surveys and all sites sampled in the Paroo River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Freshwater Catfish Golden Perch Hyrtl's Tandan Murray-Darling Rainbowfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Alien Carp Goldfish Eastern gambusia Total surveys / sites sampled Ten native and 3 alien species have also been recorded from the Warrago catchment (Table 6.21). Most native species were widespread, particularly golden perch, spangled perch and bony herring, which were present at over 50% of sites. All other native species were present at between 10% and 33% of sites. Alien species were also widespread with carp recorded at 67% of sites and eastern gambusia and goldfish at 22% of sites. Recently published surveys, post the initial data collection period for the current project, confirmed the continuing presence of all previously recorded native fish in the catchment but also recorded olive perchlet, which had not previously been recorded (Balcombe et al. 2006). Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 96

98 n Table 6.21 Species present as a percentage of all surveys and all sites sampled in the Warrago River including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Flat-headed Gudgeon Freshwater Catfish Golden Perch Hyrtl's Tandan Murray-Darling Rainbowfish Silver Perch Spangled Perch Aliens Carp Goldfish Eastern gambusia Total surveys / sites sampled 10 9 Historical data from the Paroo and Warrago Rivers is limited with most data collected from the 1970s onwards Surveys in the Paroo River in late recorded 6 native and 2 alien species (Boys et al. 2005). Native fish contributed around 50% of the total abundance across 5 sites with bony herring and golden perch widespread and abundant, contributing on average 58% and 32% respectively to the native abundance. Carp were also widespread and abundant, contributing 85% to the alien abundance and 42% to the total abundance. Surveys of 15 waterholes in October 2001 and April 2002 in the Warrago catchment recorded 10 native and 3 alien species (Balcombe et al. 2006). Bony herring and Hyrtl s tandan were widespread and abundant, contributing 40-53% and 6-41% of total abundance respectively depending on sampling time. Golden perch, spangled perch and carp were also widespread but not as abundant as the former; golden perch and spangle perch contributed less than 10% each to total abundance while carp contributed 4-16% of total abundance depending on sampling time. The Sustainable Rivers Audit (MDBC 2007) recorded 10 out of a predicted 13 species in both catchments and natives represented greater than 96% of abundance in both catchments. Natives contributed 85% of average biomass per site in the Paroo catchment, but only 57% of biomass in the Warrago catchment. The above survey results indicate a high variability in the relative contribution that various native and alien species make to community structure in the Paroo and Warrago catchments even over relative short time spans of a few months. Even so, available data indicates that the native fish communities of these basins remain relatively diverse and abundant with most predicted species being present. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 97

99 The Paroo remains relatively isolated from the rest of the Darling River system and its variable flow regime may help to limit alien species compared to other catchments. However, alien species pose an increasing threat, particularly when coupled with increasing water resource pressures that might alter natural flow regimes (Balcombe et al. 2006). Condamine-Balonne River Basin The Condamine-Balonne catchment rises on the western slopes of the Great Dividing Range in southern Queensland and includes the Condamine, Balonne, Moonie, Maranoa, Narran and Culgoa Rivers which flow south towards NSW. The Culgoa joins the Barwon upstream of Bourke to form the Darling River. Twenty one native and 4 alien species have been recorded in data collated for the current project from 98 surveys across 58 sites (Table 6.22). Of the native species, bony herring, golden perch and spangled perch were the most widespread, present at around 25-33% of sites surveyed. Australian smelt, Murray cod and Murray-Darling rainbowfish were recorded in 10-20% of sites and the remaining native species recorded at less than 10% of sites. Of the alien species goldfish and eastern gambusia were recorded at around 20% of sites, carp at 10% of sites and rainbow trout at 1% of sites. n Table 6.22 Species present as a percentage of all surveys and all sites sampled in the Condamine-Balonne River Basin including year of most recent sample for native species and year of first and last record for alien species. Species First record Last record % presence in surveys % of sites present Native Australian Smelt Bony Herring Carp Gudgeons Dwarf-flat-headed gudgeon Darling River Hardyhead Flat-headed Gudgeon Freshwater Catfish Golden Perch Hyrtl's Tandan Long-finned Eel Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive Perchlet Rendahl's Catfish River Blackfish Silver Perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 98

100 Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Aliens Carp Goldfish Eastern gambusia Rainbow Trout Total surveys / sites sampled Figure 6-26 shows the distribution of fish across zones in the Condamine-Balonne basin. Most species have been recorded across all zones, except mountain galaxias and river blackfish, which are restricted to the upland zone, and Darling River hardyhead, flat-headed gudgeon, long finned eel and Rendahl s catfish, which have only been recorded in the slopes zone. Alien species were also distributed across all zones, except rainbow trout, which was restricted to the upland zone. 100 % sites surveyed Australian Smelt Bony Herring Carp Gudgeons Darling River Hardyhead Dwarf Flatheaded Gudgeon Freshwater Catfish Golden Perch Hyrtl's Tandan Long-finned Eel Mountain Galaxias Murray Cod Murray Hardyhead Murray-Darling Rainbowfish Olive perchlet Rendahl's Catfish River Blackfish Silver Perch Southern Purple-spotted Gudgeon Spangled Perch Un-specked Hardyhead Carp Lowlands Slopes Uplands Goldfish Mosquitofish Rainbow Trout n Figure 6-26 Distribution of fish across the Condamine-Balonne basin fish species at % of sites surveyed (note all methods combined due to low survey numbers). Available data is insufficient to quantify historical trends in abundance. The most comprehensive data set for the catchment is from the Sustainable Rivers Audit pilot project (MDBC 2004), which recorded 12 out of a predicted 18 native species. Native species contributed 93% of abundance and 59% of biomass per site indicating that although native species are abundant the majority are small bodies species compared to the few aliens present. Note, more comprehensive data from surveys undertaken in QLD were unavailable for the current project. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 99

101 7. Trends in species distribution across the Murray-Darling Basin The data collected for the current project was also used in a concurrent project to map recorded locations of each species around the basin (SKM 2007b). This data formed the basis for species distribution maps published in Lintermans (2007) Records pre and post 1980 were plotted using different symbols to highlight any differences between recent and historical distributions. The 1980 demarcation was arbitrarily chosen after discussion with Mark Lintermans; it represents a compromise between having sufficient temporal data either side of the cut off date, yet still being able to detect some more historical changes in distribution. Based on an examination of survey records, discussions in Section 6 and distribution maps, Table 7.1 provides a summary of key observations on distribution for each species. Distribution maps for some key species are provided in Appendix D to provide examples of those species that have undergone a decline in range, range expansion or have remained stable. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 100

102 n Table 7.1 Summary of pre- and post distributions of native and alien fish recorded in the Murray-Darling Basin Common Name Scientific Name Pre-1980 distribution Post-1980 distribution General comments Native species Olive perchlet Ambassis agassizii Depositional zone in Condamine valley & sparse records from lower Lachlan, Murrumbidgee & Murray basins Short-finned eel Anguilla australis No pre 1980 records Source & transport zones in Border Rivers, Warrego & Macquarie valleys Sporadic records from Goulburn valley. Occasional records from ACT. Long-finned eel Anguilla reinhardtii No pre 1980 records Sporadic records from Condamine valley Silver perch Darling River hardyhead Murray hardyhead Unspecked hardyhead (southern form) Two-spined blackfish River blackfish Bidyanus bidyanus Craterocephalus amniculus Craterocephalus fluviatilis Craterocephalus stercusmuscarum fulvus Gadopsis bispinosus Gadopsis marmoratus Widespread through southern & northern parts of MDB pre & post 1980, although restricted to depositional zones in southern MDB valleys Recorded from 6 locations in the source & transport zones of Border Rivers, Gwydir & Namoi valleys. Widespread but sparse records from depositional zones of the Condamine, Namoi, Macquarie, Lachlan, Murrumbidgee & Loddon valleys Widespread but sparse records from transport zones of the Condamine, Namoi & Macquarie valleys. Recorded from depositional zones in the Lachlan, Murrumbidgee, Central Murray & Lower Murray valleys Widespread pre & post 1980 through transport & source zones in southern tributaries east of the Campaspe & including the Murrumbidgee valley Post 1980 records from across range but number of recorded locations has declined, particularly in Murrumbidgee & Lachlan valleys, upper Central Murray valley & through parts of the Darling & Condamine valleys Increased recorded locations in upper Border Rivers & Gwydir & Namoi valleys, also recorded in Condamine valley No post 1980 records from northern MDB, Lachlan or Murrumbidgee valleys. Continued presence in lower Loddon (Kerang Lakes) valley with occasional records from lower Murray River valley Increased number of recorded locations throughout range Apparent increase in recorded locations post 1980 due to classification as separate species to river blackfish Widespread pre & post 1980 through transport zones in southern & eastern tributaries, including as far north as upper Condamine valley. Also present in east Mt Lofty Ranges Distribution appears to have shifted, or become restricted to source & transport zones in Border Rivers Coastal species not normally recorded from MDB. Sporadic records likely probably due to translocations Coastal species not normally recorded from MDB. Sporadic records likely to be from elvers that have traversed Great Dividing Range in southern Queensland Still recorded across range but apparent reduction in frequency of occurrence Overall sparse records with restricted distribution to source & transport zones of north eastern tributaries of the Darling River Sparse recorded in southern MDB. Previous confusion with unspecked hardyhead may explain apparent absence from northern MDB post 1980 (see Appendix D.1) General increase in recorded locations across range possibly due to early records being identified as Murray hardyhead Widespread through southern & eastern parts of MDB although greatest density of recorded locations occurs in southern tributaries to the Murray River Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 101

103 Common Name Scientific Name Pre-1980 distribution Post-1980 distribution General comments Climbing galaxias Galaxias brevipinnis No pre 1980 records Widespread in upper Murray, Mitta Mitta below Dartmouth & lower Kiewa Rivers. Records also from Murrumbidgee, Central Murray below Hume & Goulburn/Broken systems. Introduced to MDB in inter-basin transfers from Snowy River in late 1980s. Expanding downstream in Murray & Murrumbidgee Rivers downstream of transfers from the Snowy River system Barred galaxias Galaxias fuscus Pre and post 1980 records restricted to source zone in Goulburn valley Few records reflects low sampling effort in restricted area of distribution Increased number of recorded locations Occasional sparse records in Victorian Typically a coastal species. Appears to have established land locked Common galaxias Galaxias maculatus across Victorian tributaries. Records from tributaries & Central Murray populations in northern Victoria in recent years lower Murray & lakes Mountain galaxias Flat-headed galaxias Galaxias olidus Galaxias rostratus Spotted galaxias Galaxias truttaceus No pre 1980 records Widespread pre & post 1980 through source & transport zones in southern & eastern tributaries, including as far north as source zone in Condamine valley. Also present in east Mt Lofty Ranges. Occasional records in depositional zones Widespread through lower Victorian tributaries & Central Murray. One record from upper Macquarie Similar to pre 1980 distribution, although no recent records from Murray River downstream of Murrumbidgee Post 1980 records Loddon & Campaspe valleys No pre or post 1980 records in database although have been reported from Lower Murray Pouched lamprey Geotria australis valley & some lower reaches of Victorian tributaries Four records from source zones in Lachlan, Firetailed gudgeon Hypseleotris galii One record from source zone in Namoi valley Border Rivers & Condamine valleys Widespread pre & post 1980 through southern MDB & into Border Rivers valley. Western Carp gudgeons Hypseleotris sp. carp gudgeon extends into Condamine, Warrego & Paroo valleys Leiopotherapon Widespread pre & post 1980 records from source, transport & depositional zones in all Spangled perch unicolor northern valleys. Not recorded south of the Macquarie Valley or in the lower Darling valley Self sustaining populations currently Recorded from source & transport zones in restricted to Central Murray & Seven Maccullochella southern MDB, including Murrumbidgee basin & Creeks in Goulburn basin. However, still Trout cod macquariensis east of the Loddon valley. Isolated records recorded throughout former range due to from Macquarie basin. extensive stocking effort in past years Murray cod Golden perch Maccullochella peelii peelii Macquaria ambigua Widespread throughout southern & north eastern parts of MDB including Darling & Condamine valleys. Not recorded from source zones in southern part of basin Widespread through southern & northern parts of MDB pre & post 1980 Remains widespread throughout MDB. Apparent increase in number of recorded locations probably due to stocking or increased survey effort over past 20 years Apparent expansion into upper Border Rivers, Warrego, Paroo & Lachlan basins, possibly due to stocking or increased survey effort in past 20 years. Remains widespread across range, although presence of trout represents a threat in some locations (Appendix D.2) Widespread along Central Murray but with apparently isolated population in upper Macquarie River (no records from Murrumbidgee or Lachlan Rivers) Normally a coastal species not indigenous to the MDB but has been translocated to the Loddon &Campaspe valleys Migratory species with marine phase & distribution restricted to Lower Murray valley Common coastal species that appears to have colonised upper reaches of some MDB rivers on western slopes of Great Dividing Range Database records typically do not distinguish between species in the complex Widespread & abundant throughout northern Australia extending into northern part of MDB Significant contraction in range of wild populations. Extensively stocked throughout former range (Appendix D.3) Considered to have undergone a decline across entire range, although extensive stocking may mask trends in distribution of wild stock Considered to have undergone a decline in southern parts of basin, although extensive stocking may mask trends in distribution of wild stock Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 102

104 Common Name Scientific Name Pre-1980 distribution Post-1980 distribution General comments Macquarie perch Estuary perch Murray-Darling rainbowfish Southern purplespotted gudgeon Short-headed lamprey Southern pygmy perch Macquaria australasica Macquaria colonorum Melanotaenia fluviatilis Mogurnda adspersa Mordacia mordax Nannoperca australis Predominantly recorded from transport & source zones of southern tributaries of the Murray River, including Loddon & Campaspe basins. Occasional records from depositional zones in Central Murray & Murrumbidgee valleys. Translocated to Wimmera basin Occasional records from Murray mouth. Records in database from mid & upper Darling likely to be misidentifications Widespread through northern basins, sparse through Lower & Central Murray Pre 1980 records predominantly from source & transport zones of the Condamine, Border Rivers, Macquarie & Gwydir basins. Isolated records from the Murrumbidgee & Lower Murray basins Contraction in distribution to upper reaches of tributary streams, predominantly Mitta Mitta, Ovens, Goulburn, Murrumbidgee & Lachlan basins. No post-1980 records in database but occasional anecdotal records from lower Murray Continues to be widespread in northern basins, apparent increase in number of recorded locations in Lower Murray & through lower Goulburn, Broken & Ovens basins Post 1980 records restricted to Condamine, Gwydir & Namoi basins & Cardross Lakes in Lower Murray basin Occasional pres & post 1980 records through Lower Murray valley extending into lower Lachlan & Central Murray valleys Widespread records from transport & Contraction in distribution with reduction in depositional zones in southern MDB, including post 1980 records from Murrumbidgee, Murrumbidgee & Lower Murray basin & east Mt Central Murray & Loddon basins Lofty Ranges. Yarra pygmy perch Nannoperca obscura No pre or post 1980 database records, although has recently been recorded from several locations in South Australia. Bony herring Nematalosa erebi Widespread through northern MDB & Lower Widespread through northern MDB & Lower Murray. Occasional records in southern Murray basin MDB. Hyrtl's tandan Neosilurus hyrtlii No Pre 1980 records Sparse records from upper Condamine, Warrego & Paroo basins Flat-headed gudgeon Dwarf flat-headed gudgeon Philypnodon grandiceps Philypnodon sp.1 Widespread in Murray catchment upstream of Darling Junction, including Victorian tributaries, Murrumbidgee & Lachlan basins Apparent expansion of range to Macquarie & Lower Murray valleys. Isolated records from mid Darling, Condamine & Warrego basins No pre or post 1980 records in databse although known to be present in isolated locations in lower Murray and Murrumbidgee basins Rendahl s tandan Porochilus rendahli No pre 1980 records Recent record from mid Condamine basin Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 103 Contraction in distribution over past 20 years (Appendix D.4) Generally restricted to estuarine reaches. Murray mouth represents western extent of distribution Widespread but relatively sparse through northern & southern parts of basin Contraction in range to northern parts of MDB. Current presence in Cardross Lakes is unknown & unlikely to be present else where in southern MDB Migratory species with marine phase restricted to Lower Murray valley but occasionally extends long distances inland Once widespread through southern MDB it appears to have undergone a contraction in distribution in recent years, particularly from lower reaches (Appendix D.5) Specific record locations were not available in time for inclusion in current database compilation Widespread but dominant in northern & western parts of MDB. Apparently common across its range in northern Australia, restricted to unregulated northern MDB rivers Widespread in southern MDB with possible increased distribution in to northern MDB in past 20 years (Appendix D.6) Typically a coastal species although reportedly present in isolated locations. Can be confused with flat-headed gudgeon Patchily distributed across northern Australia, only recently recorded in MDB in the Condamine valley

105 Common Name Scientific Name Pre-1980 distribution Post-1980 distribution General comments Congolli Pseudaphritis urvillii Occasion records from Lower Murray basin around Murray mouth Increased number of records in Murray mouth & lower lakes region Australian smelt Retropinna semoni Widespread pre and post 1980 records through north & south of MDB Freshwater catfish Tandanus tandanus Widespread through southern & northern basins but with concentrated records from upper Condamine, Border Rivers, Gwydir, Namoi & Macquarie basins. Occasional records from upper reaches of southern basins. Similar distribution to pre Increased records from translocated population in Wimmera Valley Migratory species with marine phase & restricted distribution to lower Murray Widespread throughout MDB with no apparent change in historical distribution Persistent across range but considered to have undergone an overall decline in southern parts of basin (Appendix D.7) Alien species Goldfish x carp Goldfish Carp Eastern gambusia Oriental weatherloach Rainbow trout Quinnat salmon Redfin perch Roach Carassius auratus Cyprinus carpio Gambusia holbrooki Misgurnus anguillicaudatus Oncorhynchus mykiss Oncorhynchus tshawytscha Perca fluviatilis Rutilis rutilus One record from upper Goulburn but often not recorded in databases. Widespread in southern MDB, & lowland zone of Condamine basin Increased number of recorded locations though Victorian tributaries & Central Murray Increased recorded locations in northern MDB including Paroo, Warrego, upper Condamine, Border Rivers, Gwydir & Namoi basins Widespread in southern MDB, sparse records Widespread in southern & northern MDB in northern MDB Widespread throughout MDB, although Increased recorded locations throughout restricted to lower reaches of Paroo, Warrego & MDB, including upper Paroo & Condamine Condamine basins basins Numerous Post 1980 records in Murrumbidgee valley around & downstream No pre 1980 records of Canberra & in the Central Murray & lower reaches of the Ovens, Broken & Campaspe basins Widespread pre & post 1980 in cooler higher altitude regions of southern & eastern MDB, including new England Tablelands & Eastern Mt Lofty Ranges. Occasional mid & lower Murray records. Pre 1980 records from Ovens, Loddon & Post 1980 records from Ovens, Goulburn & Wimmera basins Wimmera basins Widespread pre & post 1980 records throughout source, transport & depositional zones of southern tributaries & Lower Murray basin. Occasional occurrence in source & transport zones of the Macquarie, Gwyider & Border Rivers basins Pre & post 1980 records concentrated in source & transport zones of Goulburn & Campaspe valleys. Isolated occurrence in Mitta Mitta & Loddon basins Apparent expansion in range in past 20 years likely due to recognition as hybrid Range has expanded in past 20 years to transport & source zones of northern MDB rivers & is now widely distributed through entire MDB Range has expanded in past 20 years to northern MDB & is now widely distributed through entire MDB Range has expanded in past 20 years to upper reaches of northern MDB rivers & is now widely distributed through entire MDB (Appendix D.9) First recorded post 1980, currently restricted to upper Murrumbidgee & Central Murray valleys, although some isolated records occur elsewhere Very few records, escapee from fish farms on Ovens & Goulburn Rivers, stocked in some Western District lakes in southern Victoria Restricted to isolated locations in source & transport zones of some southern tributaries Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 104

106 Common Name Scientific Name Pre-1980 distribution Post-1980 distribution General comments Atlantic salmon Salmo salar Goulburn valley (pre & post 1980 records) Populations in the Rubicon River (Goulburn valley) sustained by stocking Brown trout Salmo trutta Widespread pre & post 1980 in higher altitude regions of southern & eastern MDB, including new England Tablelands & Eastern Mt Lofty Ranges. Occasional mid & lower Murray records. Brook char Salvenus fontinalis One record from upper Macquarie River No post 1980 records No recent records although there is an apparent self sustaining population in the New England Tablelands Tench Tinca tinca Widespread throughout southern MDB tributaries & lower Murrumbidgee, Lachlan & Lower Murray basins Apparent contraction in range to Wimmera, Avoca, Loddon, Campaspe & Goulburn basins Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 105

107 8. Basin wide summary of native fish status 8.1 Current status The abundance and distribution of fish communities in the Murray-Darling Basin has been shown to exhibit broad spatial trends that have been subject to long-term changes. In general, native fish communities within the Murray-Darling Basin have declined in abundance and distribution. Many populations of native fish, which were considered to be widespread throughout the Basin prior to European settlement, are now fragmented and reproductively isolated. Some of the main reasons identified for this decline in abundance and distribution are habitat degradation, impacts of bush fire runoff, river regulation, barriers to fish passage and the invasion of exotic fish species. In some instances, it has been suggested that in the mid 1900s the impacts of bush fires on top of water resource development in a number of catchments resulted in a reduction in native fish abundance, following which alien species rapidly expanded before native fish could recover, and in many instances have never recovered from. The ability of native fish to recover and recolonise from disturbance compared to alien fish should be further investigated to see if there are aspects of recolonisation and recovery that can be exploited to assist give native species an advantage over alien species, for example following the current drought induced disturbance. In general, fish communities tend to show differences between highly regulated systems, predominantly in the south of the basin, and those in the northern basin and arid zone areas that retain a more natural flow. However, it must be noted that regional stocking and translocation regimes have bolstered stocks of some species such as Murray cod and golden perch, for example, in the Lower Goulburn River and the Murray River. The distribution and abundance of exotic species within the Murray-Darling Basin tends to be widespread, with species such as carp, redfin perch and eastern gambusia accounting for large proportions of fish catches in surveys conducted in most lowland river regions and salmonid species dominating abundances in many upland regions of Southern NSW and Victoria. Despite some local increases in fish abundance in recent years in some locations it is likely that the majority of decline in native fish abundance occurred in the late 19 th and early to mid 20 th centuries. Hence patterns observed over the last years are likely to represent relatively small changes in abundance compared to the longer term historical decline in abundance that has occurred in some basins. The Sustainable Rivers Audit program provides a standardised assessment of current abundance and will provide a benchmark against which the benefit of activities aimed at restoring fish numbers can be assessed. However, there is insufficient historical data to quantify historic changes. The first SRA sampling of all basins is nearing completion and the result of the audit provide an indication of the current fish communities and help put some of the anecdotal evidence of native Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 106

108 fish decline discussed in Section 6 in context across the MDB. Across all basins, the number of native species caught has been less than predicted (Figure 8-1). The highest number of native species were predicted for the Lower Murray, mid Murray and Goulburn basins, the least number of native species were predicted for the Warrago and Paroo basins, and for basins comprising predominantly upland streams (i.e the Mitta Mitta and Upper Murray basins). Across most of the MDB only around 50% of the expected species were recorded in each basin, except the Namoi, Border and Condamine basins where over 75% of the predicted species were recorded. Alien species were recorded across all basins, although northern basins tend to support fewer alien species than southern basins (e.g. only alien species were recorded in the Condamine, Warrago and Paroo catchments compared to more than 5 in most other basins) Number of species Lower Murray Mid Murray Upper Murray Avoca Loddon Goulburn Broken Ovens Kiewa MiAa Murrumbidgee Number of alien species caught NaNve species predicted but not caught Lachlan Darling Macquarie Namoi Warago Paroo Border Rivers Condamine n Figure 8-1 Number of fish caught across SRA river valleys (source data from MDBC 2004, Gilligan 2005b, MDBC 2006, 2007). (Note data for Murrumbidgee catchment is from Gilligan (2005b) because SRA data is as yet unavailable for that catchment.) Despite the low number of expected species in the lower and mid Murray catchments more than 90% of the number of fish per site were native, however, natives only contributed to 36% and 48% of the total biomass (Figure 8-2). A similar patterns was observed in northern and more arid zone basins, such as the Darling, Condamine, Paroo and Warrago, although in the Paroo catchment natives contributed 85% of mean biomass per site. In some catchments the proportion of native biomass was less than 15% of the average biomass per site (e.g. the Upper Murray (4%), the Mitta Mitta (8%), the Avoca (8%), the Ovens (10%), the Murrumbidgee (11%) and the Kiewa (10%)). The high proportion of alien biomass was a result of the widespread distribution of carp and redfin across nearly all basins and of salmonids in southern upland zones. Under these circumstances, native species present are predominantly small bodied (e.g. Australian smelt, carp gudgeons, flat- Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 107

109 headed gudgeon and bony herring) and while numerous, contribute little to total biomass, which is dominated by the much larger alien species. Average biomass per site (g) % number of na1ve fish per site Alien biomass n Figure 8-2 Proportion of native biomass and abundance across SRA river valleys (source data from MDBC 2004, Gilligan 2005b, MDBC 2006, 2007). (Note data for Murrumbidgee catchment is from Gilligan (2005b) because SRA data is as yet unavailable for that catchment.) In the Murrumbidgee and Lower Murray-Darling catchments Gilligan (2005b, 2005a) considered fish community composition had been relatively stable over the past years and that perhaps an equilibrium between alien and native species had been reached. If this is the case and assuming the total biomass represents a surrogate for total carrying capacity and possibly total abundance, then the proportion of native biomass to total biomass provides perhaps the best evidence yet that native fish as a whole have undergone a significant reduction in abundance across the entire MDB. As indicated above, native biomass is less than 10% of total biomass in some locations, and this lends weight to the assumptions in the Native Fish Strategy that current native abundance could be as low as 10% of pre-european conditions (MDBC 2003). It also suggests that in some northern basin catchments, like the Paroo and Condamine, current native fish abundance may remain relatively comparable to pre-european conditions, assuming current biomass represents an surrogate for abundance. The relationship between biomass, carrying capacity and abundance is worthy of further investigation to determine if such a relationship does in fact exist. Presumably the carrying capacity of a system is finite and if a relationship between carrying capacity and potential biomass or abundance could be established then carrying capacity could be used as a measure to help predict potential improvements in native fish abundance that could be achieved if the biomass of alien species could be reduced. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 108

110 In summary, the data suggest that there have been declines in the abundance of native fish across the MDB. This is variable between catchments, but the southern basins tend to have a lower proportion of native biomass to total biomass than northern basins, southern basins also support a larger number of alien species than northern arid-zone basins, which accounts for the greater alien biomass. Across the entire MDB no species have become extinct, although contraction in distribution of some species has occurred at a regional scale and some species are now likely to be regionally extinct, for example southern purple-spotted gudgeon and olive perchlet in the southern MDB. In addition, populations of some large native species, such as Murray cod and golden perch, while apparently stable across their range, are probably maintained by stocking, as evidenced by a lack of confirmed recruitment in some locations, for example, in the Campaspe catchment (Humphries et al. 2002). Conversely, stocking of trout cod for conservation purposes appears to have been successful at establishing new breeding populations in the lower Goulburn and possibly the lower Murrumbidgee catchments (Koster et al. 2004, Gilligan 2005b). While translocations and stocking of Macquarie perch have been successful at maintaining some populations, for example in Queanbeyan River (Lintermans 2006) and in Hollands Creek (Arthur Rylah Institute 2007) and the Yea River. 8.2 Key drivers of change The rivers of the Murray-Darling Basin have undergone significant change since the arrival of Europeans (Table 8.1) and the cumulative impacts have contributed to the decline in native fish. Degradation of in-stream habitat began as early as the 1850s when systematic de-snagging of the lower reaches of the Murray, Darling and Murrumbidgee Rivers commenced to improve passage and aid navigation for paddle steamers (Treadwell et al. 1999). Habitat degradation has continued on various scales to the current day. The construction of large dams and small weirs along most rivers in the Basin, particularly those in the southern Basin, has created barriers to fish passage (Mallen-Cooper et al. 1995, Koehn et al. 2004) and contributes to thermal pollution as a result of cold water releases (Lugg 1999). River regulation has also resulted in changed flooding regimes, shifts in the seasonality of flow and generally an overall reduction in flow as a result of abstractions for agricultural development (Maheshwari et al. 1995). Catchment clearing, subsequent erosion and increased salinity are also contributing to a decline in the health and ecological integrity of many rivers in the Murray-Darling Basin. n Table 8.1 A history of change in the Murray-Darling Basin (Data sourced from Powell 1993 unless otherwise indicated) Date Event Reference Early explorers traverse the MDB, recording an abundance of native fish in (Scott 2005) Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 109

111 Date Event Reference most rivers crossed Stock routes from NSW to SA established along the River Murray 1850 Rapid settlement of many parts of the basin was underway with immediate environmental impacts associated with land clearing, timber felling, mining, drainage, overgrazing and cultivation. Particular impacts included sludge and sand deposition in streambeds and diversion of water for mining activities The first paddle steamers successfully travelled upstream from Goolwa to Echuca. By steamers were trading and operating along the Murray and lower Darling Rivers and ten years later 240 boats were operating along 4000 km of waterway Landholders begin to discuss management of River Murray, water resource and navigation 1863 Discussions held between Victorian, NSW and South Australia regarding the construction of locks to aid navigation 1865 Newspaper editorials call for protection of upland areas of the Basin from land degradation caused by timber felling, mining, road construction and over ploughing. The Loddon, Campaspe and Avoca Rivers are described as..fast becoming mere channels for the efflux of sludge and sand 1870 Irrigation commenced in Victoria (Phillips 1972) (Argus, 16 October 1865) 1873 Successful introduction of Murray cod and other fish into Wimmera River (Argus, 14 Apr 1873). 1880s Increased irrigation resulting in a reduction in river levels that impacted river trade resulted in ongoing conflicts Construction of Torrumbarry Weir commences Severe drought forced cooperation between colonies/states that resulted in the development of an agreement on the management of the Murray River, which culminated in the signing of the River Murray Water Agreement in 1915 and the subsequent establishment of the River Murray Commission in Johann Tepper, in an article on trees in nature, describes the disastrous impacts of clearing and cultivation on the land and waterways within the Basin. Other notable scientists have similar misgivings around the same time about the rate of deforestation. (Tepper 1896) Irrigation-induced salinity appears at Cohuna, Victoria (Mackay and Eastburn 1990) 1913 Construction of navigation locks along the River Murray commence with Lock/Weir 1 at Blanchtown, SA Construction of locks and weirs continues although mostly too late to be of any benefit to the river trade industry. Only 3 of the original 16 locks proposed for the Murray above the Darling junction were constructed Paddle steamer trade declined significantly with the extension of railways and a reduction in navigable waterway length due to weir construction Soldier settlement schemes based on irrigation established in NSW, Victoria and South Australia Construction of Hume Dam commenced. 1920s-1930s Significant salinity attributed to flood irrigation appeared in northern Victoria Torrumbarry Weir completed 1928 Lake Victoria storage completed, Burrinjuck Dam construction completed on the Murrumbidgee River Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 110

112 Date Event Reference 1936 Hume Dam construction completed 1937 Euston weir and Lock 15 completed 1939 Yarrawonga Weir completed 1940 River Murray Barrages constructed to prevent saline intrusion to Lakes Alexandrina and Albert. Maude Weir and Redbank Weir constructed on the Murrumbidgee River 1944 One of the first fishway in the basin built on Euston Weir (Mallen-Cooper and Brand 2007) 1954 Mannum-Adelaide pipeline completed to supply Adelaide with drinking water from the River Murray 1956 Largest flood ever recorded throughout the Murray Valley 1960 s The paddle steamer Industry was still desnagging in the lower River Murray. (Phillips 1972) 1964 Carp reported in Lake Hawthorn near Mildura (although they are likely to have been introduced to the Basin in the 1940s and 1950s based on some reports of carp from the upper Murrumbidgee and in irrigation channels) 1966 Snowy Mountains Scheme water diverted to the Murray Severe drought highlights salinity issues along the River Murray 1968 Moratorium on further irrigation development in SA. Menindee Lakes storages constructed on the Darling River 1972 Construction of Dartmouth Dam on the Mitta Mitta River commences 1979 Dartmouth Dam (3906 GL) construction completed ,000 snags removed from the Murray River between Hume Dam and Yarrawonga Severe drought closes the River Murray mouth for the first time in European recorded history. Dust storms in Melbourne create public awareness of land degradation issues 1988 Murray-Darling Basin Commission succeeds River Murray Commission 1990 Fish Management Plan approved Major algal bloom along the Darling River 1991 Fishway built on Torrumbarry weir 2001 Ministerial Council approves construction of fish passage from Hume Weir to sea (by 2007) Ministerial Council approves Native Fish Strategy and target to restore native fish abundance to 60% of pre-european conditions Fishways constructed on Locks 7, 8, 9, 10 and 15, on Torrumbarry and Yarrawonga Weirs and at the Barrages, planning and construction is underway on several more fishways. Fishways are also constructed or planned for barriers on many other waterways in the Basin. (Weatherley and Lake 1967, Koehn et al. 2000) (River Murray Commission 1975) Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 111

113 Habitat loss and river degradation by human activities is widely accepted as the primary causes of decline in the abundance and distribution of native fish populations (MDBC 2003). The loss of habitat through de-snagging, altered flow and temperature regimes, the loss of riparian vegetation and barriers to passage are considered key processes threatening the survival of native fish and native fish communities in the Murray-Darling Basin (SKM 2003). In addition, river regulation may have enhanced conditions for the spread of exotic species (Humphries and Lake 2000), which compete with native fish for habitat and resources. The outcomes from the current study have demonstrated a general decline in the abundance of many native fish species across the basin, but have also highlighted the difficulty in examining trends in the absence of appropriate data. The only way to satisfactorily assess the status of fish communities in the basin is through a standardised approach that comes with a long term commitment to continue monitoring in order to assess future trends, the Sustainable Rivers Audit provide such an approach and should provide the benchmark against which the status of native fish can be compared with in the future. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 112

114 9. Conclusions and recommendations 9.1 Conclusions This project aimed to assess historical trends in the abundance and distribution of native fish across the Murray-Darling Basin. Fish survey data was collected from a range of sources including state agencies, museum records and technical literature. A review of available data indicated that for the most part there was insufficient effort data in order to undertake a standardised quantitative assessment of historical trends in abundance. Hence, an approach was adopted based on a review of historical literature and semi-quantitative assessments were data permitted. Based on anecdotal evidence from early explorers and analysis of commercial catch data it would seem that the majority of decline in native fish abundance occurred in the late 19 th and early to mid 20 th centuries. Overfishing, catchment clearing resulting in river degradation, water resource development, particularly changes in river flow and barriers to fish passage, and the introduction and expansion of alien species were considered the key contributors to the decline in native fish abundance across the basin. Declines in native fish abundance, if measured as a proportion of current total biomass, have occurred across the entire MDB, although southern basins tend to have a greater alien fish abundance than northern and arid-zone basins. Southern basins also tend to have a lower native species diversity than predicted compared to northern basins. While no native species has become extinct across the basin many species have shown a contraction in distribution and regional extinctions have occurred, particularly in the southern basin. The Sustainable River Audit fish theme provides a standardised benchmark against which future trends in fish abundance and distribution can be quantified. 9.2 Recommendations for further investigations Investigation in to the carrying capacity of streams. Anecdotal evidence indicated that most rivers carried a high abundance of large bodied native fish. This high biomass of native fish now seems to have been replaced with a high abundance of large bodied alien fish such as carp, redfin perch and salmonids. It is recommended that an investigation be undertaken to define the carrying capacity of a select number of river reaches and to determine if relationships can be established between carrying capacity and total fish biomass. This investigation should also determine whether carrying capacity or total biomass can be used as a surrogate for abundance (i.e. if the biomass of alien species could be reduced would this enable an increase in the biomass of native species and hence an increase in abundance and or diversity of native species). Such an investigation would require a combination of desktop review and experimental research carried out at a number of locations and perhaps in mesocosms where carrying capacity could be controlled. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 113

115 The outcomes of such an investigation may provide empirical relationships between carrying capacity, biomass and abundance that can be used to 1) confirm the decline in native fish abundance, 2) assess the potential carrying capacity of various systems and 3) determine with more confidence the potential improvement in native fish abundance that could be achieved if the biomass of alien species were reduced. Such an investigation would need to run for several years in order to obtain seasonal data, and across a range of sites ranging from those with a large alien biomass to a low alien biomass. An indicative cost for such an investigation is $500, Investigation of recovery and recolonisation ability of native compared to alien fish species Anecdotal observations suggest that following periods of disturbance, such as bushfire impacts, alien species were able to more rapidly colonise affected rivers and outcompete native species to the point that native species may never have recovered. This is not to say that native species could not recover from such disturbance, rather their recovery mechanisms may be different to that of alien species. Recovery following disturbance is likely related to the speed at which species can move into new habitats, their specific habitat requirements and factors influencing recruitment. Mobile species with generalist habitat requirements and non-specific or opportunistic breeding requirements are likely to be more successful at recolonising disturbed areas that those with low mobility or specialist requirements. An investigation is recommended to assess the ability of native and alien species to recover from disturbance. This would help to better understand the likely pathways by which different species colonise new habitats and may identify some aspects of their life history that could be 1) used to help promote native species recolonisation and 2) limit alien species recolonisation of disturbed areas. An example of such a trait that is already being exploited to control carp is their preference to jump over obstacles in the case of the Williams carp separation cages. A number of studies related to the above concepts are already being undertaken around the basin, particularly associated with understanding the impact the current drought is having on native species and their ability to recover. The outcomes of this project would be a review the current knowledge around recovery and recolonisation of native and alien species and scope further investigations to identify life history traits that can be exploited in the future to assist native fish. Such a review would need to run for 1 to 2 years and involve a number of workshops and discussions with researchers. An indicative cost is $150,000. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 114

116 10. References Arthur Rylah Institute Holland's Creek demonstration reach: background and recommendations. Department of Sustainability and Environment, Melbourne. Balcombe, S. R., A. A. Arthington, N. D. Foster, M. C. Thoms, G. G. Wilson, and S. E. Bunn Fish assemblages of an Australian dryland river: abundance, assemblage structure and recruitment patterns in the Warrego River, Murray-Darling Basin. Marine and Freshwater Research 57: Balme, J years of fishery in western New South Wales. Archaeology Oceania 30:1-21. Baxter, A Trout Management Group fish population surveys, ; location of sampling sites and fish species caught. Technical Report Series No. 15. December Department of Conservation, Forests and Lands, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria. Boys, C. A., G. Esslemont, and M. C. Thoms Fish habitat assessment and protection in the Barwon- Darling and Paroo Rivers. NSW Department of Primary Industries - Fisheries Final Report Series No. 78. Brumley, A., A. K. Morison, and J. Anderson Revision of the conservation status of several species of warmwater native fish. After surveys of selected sites in Northern Victoria ( ). Technical Report Series No. 33. February Department of Conservation, Forests and Lands, Fisheries Division, Kaiela Fisheries Research Station. Arthur Rylah Institute for Environmental Research, Shepparton, Victoria. Brumley, A. R Past and present distributions of Golden Perch Macquaria ambigua (Pisces: Percichthyidae) in Victoria, with reference to releases of hatchery produced fry. Proceedings of the Royal Society of Victoria 99: Brumley, A. R Family Cyprinidae: carps, minnows etc. Pages in R. M. McDowall, editor. Freshwater Fishes of South-Eastern Australia. Reed Books, Chatswood, NSW. Cadwallader, P. L J.O. Langtry's Murray River investigations. Fisheries and Wildlife Papers of Victoria. No. 13. Cadwallader, P. L Distribution of native and introduced fish in the Seven Creeks river system, Victoria. Australian Journal of Ecology. 4: Cadwallader, P. L Past and present distributions and translocations of Macquarie Perch Macquaria australasica (Pisces: Percichthyidae), with particular reference to Victoria. Proceedings of the Royal Society of Victoria. 93: Cadwallader, P. L The Macquarie Perch of Lake Dartmouth. Australian Fisheries 4: Cadwallader, P. L., and G. J. Gooley Past and present distributions and translocations of Murray Cod Maccullochella peelii and Trout Cod Maccullochella macquariensis (Pisces: Percichthyidae) in Victoria. Proceedings of the Royal Society of Victoria 96: Close, P., and G. Aland The Impact of Instream Barriers on Fish Assemblages in Lower Reaches of the Broken River and Seven Creeks, and Preliminary Assessment of fish passage through the Euroa Town and Lake Benalla Fishways. Natural Resources and Environment. Copeland, C., E. Schooneveldt-Reid, and S. Neller Fish Everywhere - an oral history of fish and their habitats in the Gwydir River. NSW Fisheries. Cottingham, P., G. Hannan, T. Hillman, J. Koehn, L. Metzeling, J. Roberts, and I. Rutherfurd Report of the Ovens Scientific Panel on the environmental condition and flow in the Ovens River. Cooperative Research Centre for Freshwater Ecology: Technical Report 9/2001. Dargin, P Aboriginal fisheries of the Darling-Barwon Rivers. Brewarrina Historical Society, Dubbo, New South Wales. Douglas, J. D The Macquarie Perch of Lake Dartmouth. Page 69 in Proceedings of the Australian Society for Fish Biology, Annual Meeting, Wellington, New Zealand. Ebner, B Murray cod an apex predator in the Murray River, Australia. Ecology of Freshwater Fish 15: Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 115

117 Ellis, I Ecology of the Murray hardyhead Craterocephalus fluviatilis (McCulloch), family Atherinidae. Murray-Darling Freshwater Research Centre, Lower Basin Laboratory. Report prepared for the Mallee Catchment Management Authority Faragher, R. A., P. Brown, and J. H. Harris Population surveys of the endangered fish species trout cod (Maccullochella macquariensis) and eastern cod (M. ikei). NSW Fisheries Research Institute, Cronulla. Fisheries Scientific Committee Final recommendation: Aquatic ecological community in the natural drainage system of the lowland catchment of the Lachlan River. Fisheries Scientific Committee, NSW. Gilligan, D. 2005a. Fish communities of the Lower Murray-Darling catchment: status and trends. NSW Department of Primary Industries - Fisheries Final Report Series No. 83, Narrandera Fisheries Centre, Narrandera, NSW. Gilligan, D. 2005b. Fish communities of the Murrumbidgee catchment: Status and trends., NSW Department of Primary Industries - Fisheries Final Report Series No. 75. Gilligan, D., and T. Rayner The distribution, spread, ecological impacts and potential control of carp in the upper Murray River - Fisheries Reseach Report Series 14. NSW Department of Primary Industries. Hammer, M., and K. F. Walker A catalogue of South Australian freshwater fshes, including new records, range extensions and translocations. Transactions of the Royal Society of South Australia 128: Harris, J. H., and P. Gehrke Fish and rivers in stress - the NSW rivers survey. NSW Fisheries Office of Conservation and the Cooperative Research Centre for Freshwater Ecology, Cronulla, NSW. Humphries, P Historical indigenous use of aquatic resources in Australia's Murray-Darling Basin, and its implications for river management. Ecological Management and Restoration 8: Humphries, P., P. Brown, J. Douglas, A. Pickworth, R. Strongman, K. Hall, and L. Serafini Flowrelated patterns in abundance and composition of the fish fauna of a degraded Australian lowland river. Freshwater Biology:1-25. Humphries, P., P. Brown, J. Douglas, A. Pickworth, R. Strongman, K. Hall, and L. Serafini Flowrelated patterns in abundance and composition of the fish fauna of a degraded Australian lowland river. Freshwater Biology: Humphries, P., and P. S. Lake Fish larvae and the management of regulated rivers. Regulated Rivers: Research and Management. Special Issue: Australian Lowland Rivers 16: Humphries, P., L. G. Serafini, and A. J. King River regulation and fish larvae: variation through space and time. Freshwater Biology 47: Knight, M. A., A. Tsolos, and A. M. Doonan South Australian Fisheries and Aquaculture Information and Statistics Report. SARDI Research Report Series No 60. South Australian Research and Development Institute. Koehn, J., A. Brumley, and P. Gehrke Managing the impacts of carp. Department of Rural Sciences, Department of Agriculture, Fisheries and Forestry - Australia, Canberra. Koehn, J., I. Stuart, and D. Crook Linking ecological importance of downstream fish movements to management of Murray-Darling Basin fish populations. Pages in Downstream movement of fish in the Murray-Darling Basin - Workshop held in Canberra, 3-4 June 2003: Statement, recommendations and supporting papers. Murray Darling Basin Commission, Canberra. Koehn, J. D., T. J. Doeg, D. J. Harrington, and G. A. Milledge The effects of Dartmouth Dam on the aquatic fauna of the Mitta Mitta River. Victoria, Department of Conservation and Natural Resources, Heidelberg. Koster, W. M., D. Crook, and P. Fairbrother Surveys of fish communities in the lower Goulburn River. Annual report 2003/2004. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Victoria. Lintermans, M Recolonization by the Mountain Galaxid Galaxias olidus of a montane stream after the eradication of Rainbow Trout Oncorhynchus mykiss. Marine and Freshwater Research 51: Lintermans, M Fish in the upper Murrumbidgee catchment: a review of current knowledge., Environment ACT, Canberra. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 116

118 Lintermans, M The re-establishment of endangered Macquarie perch Macquaria australasica in the Queanbeyan River, New South Wales, with an examination of dietary overlap with alien trout. Environment ACT and Cooperative Research Centre for Freshwater Ecology, Canberra. Lintermans, M Fishes of the Murray-Darling Basin: An introductory guide. Murray-Darling Basin Commission, Canberra. Llewellyn, L The distribution of fish in New South Wales. Australian Society for Limnology Special Publication No 7:70. Lloyd, L. N., and K. F. Walker Distribution and conservation status of small freshwater fish in the River Murray, South Australia. Transactions of the Royal Society of South Australia 110: Lugg, A Eternal winter in our rivers. Addressing the issue of cold water pollution. Unpublished Report, NSW Fisheries, Nowra. Lyon NECMA White Paper Program: Ovens Basin Perch Survey. Arthur Rylah Institute for Environmental Research Department of Natural Resources and Environment for the North Central Catchment Management Authority. Mackay, N., and D. Eastburn, editors The Murray. Murray-Darling Basin Commission, Canberra. MAFRI A preliminary assessment of the Broken Creek fishways. Report prepared for the Goulburn Broken Catchment Management Authority by the Marine and Freshwater Resources Institute, Snobs Creek. Maheshwari, B. L., K. F. Walker, and T. A. McMahon Effects of regulation on the flow regime of the River Murray, Australia. Regulated Rivers: Research and Management 10: Mallen-Cooper, M., and D. A. Brand Non-salmonids in a salmonid fishway: what do 50 years of data tell us about past and future fish passage? Fisheries Management and Ecology 14: Mallen-Cooper, M., I. Stuart, F. Hides-Pearson, and J. Harris Fish migration in the Murray River and assessment of the Torrumbarry fishway: final report. New South Wales Fisheries Research Institute, Sydney. McGuckin, J., and T. Doeg Investigation of Aquatic Ecosystems of the Campaspe Catchment. Report prepared for North Central Catchment Management Authority as part of the Campaspe River Health Recovery Plan. McGuckin, J., and T. J. Doeg Investigation of aquatic ecosystems of the Loddon catchment. North Central Catchment Management Authority, Huntly. MDBC Native Fish Strategy for the Murray-Darling Basin Murray-Darling Basin Commission, Canberra. MDBC Fish theme pilot audit technical report - Sustainable Rivers Audit. Murray-Darling Basin Commission, Canberra. MDBC Sustainable Rivers Audit. Implementation Period 1 ( ) Progress Report. Report to the Murray-Darling Basin Ministerial Council prepared by the Independent Sustainable Rivers Audit Group. MDBC Sustainable Rivers Audit. Implementation Period 2 ( ) Summary report. Report to the Murray-Darling Basin Ministerial Council prepared by the Independent Sustainable Rivers Audit Group and the Murray-Darling Basin Commission. NSW Department of Primary Industries Review of environmental factors: NSW Inland Restricted Fishery. NSW Department of Primary Industries. Phillips, P. J River boat days. Lansdowne Press, Melbourne. Pormorin, K Campaspe River at Kyneton. Fisheries Victoria Assessment Report Series No. 01. Powell, J. M The emergence of bioregionalism in the Murray-Darling Basin. Murray-Darling Basin Commission, Canberra. Puckridge, J. T., and K. F. Walker Reproductive biology and larval development of a Gizzard Shad, Nematalosa erebi in the River Murray, South Australia. Australian Journal of Freshwater and Marine Research 41: Reid, D. D., J. H. Harris, and D. J. Chapman NSW inland commercial fishery data analysis. FRDC Project No. 94/027. Fisheries Research and Development Corporation. River Murray Commission Environmental considerations relevant to the proposal for desnagging of the River Murray between Hume Dam and Yarrawonga. River Murray Commission, Canberra. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 117

119 Rowland, S. J Aspects of the history and fishery of the Murray Cod, Maccullochella peeli (Mitchell) (Percichthyidae). Proceedings of the Linnean Society of New South Wales 111: Rowland, S. J Overview of the history, fishery, biology and aquaculture of Murray cod (Maccullochella peelii peelii). Pages in Management of Murray cod in the Murray-Darling Basin: Statements, recommendations and supporting papers. Proceedings of a workshop held in Canberra ACT, June Murray-Darling Basin Commission, Canberra. Schiller, C., A. M. Bruce, and P. Gehrke Distribution and abundance of native fish in New South Wales rivers. Pages in J. H. Harris and P. Gehrke, editors. Fish and Rivers in Stress - the NSW Rivers Survey. NSW Fisheries Office of Conservation and the CRC for Freshwater Ecology, Cronulla. Scott, A Historical evidence of native fish in the Murray-Darling Basin at the time of European settlement - from the diaries of the first explorers. CRC for Freshwater Ecology, Canberra, ACT. SKM Review of Habitat Associations of Native Fish in the Murray Darling Basin. Murray Darling Basin Commission Project R2105. Report by Sinclair Knight Merz for the Murray Darling Basin Commission. SKM Management options for improving the health of the Mitta Mitta River downstream of Dartmouth Dam. Report prepared by Sinclair Knight Merz for Goulburn-Murray Water. SKM. 2007a. Modelling of the effects of cold water releases and potential mitigation measures on the ecology of the Murray River downstream of Hume Dam: Ecological assessment. Report prepared by Sinclair Knight Merz for NSW State Water. SKM. 2007b. Spatial distribution of fish species within the Murray-Darling Basin R5007. Report prepared by Sinclair Knight Merz for the Murray-Darling Basin Commission. SKM. 2007c. Survey of distribution, abundance and structure of fish populations and communities - North Central Catchment Management Authority. Report prepared by Sinclair Knight Merz for the North Central Catchment Management Authority. SKM Monitoring response to environmental flows in the Loddon and Campaspe Rivers: 2007 fish survey. Report prepared by Sinclair Knight Merz for the North Central Catchment Management Authority Sloan, S Management plan for the South Australian Lakes and Coorong Fishery. The South Australian Fisheries Management Series Paper no. 44. Fisheries Division of Primary Industries and Resources. Swales, S., and S. J. Curran Survey of the fish resources of the Macquarie Marshes. NSW Fisheries Research Institute report to the NSW Department of Water Resources. Tennant, W., G. Gooley, and J. Douglas Evaluation of operational river management works and aquatic habitat restoration in the Mid-Broken River catchment. Progress report - November I.D&A Pty Ltd and Marine and Freshwater Resources Institute. Tepper, J. G. O Trees and their role in nature. Agricultural Gazette of NSW 7: Thoms, M., R. Norris, J. H. Harris, D. Williams, and P. Cottingham Environmental scan of the Namoi River valley. Report prepared for the Department of Land and Water Conservation and the Namoi River Management Committee. Todd, C. R., T. Ryan, S. Nicol, and A. R. Bearlin The impact of cold water releases on the critical period of post-spawning survival and its implications for Murray cod (Maccullochella peelii peelii): a case study of the Mitta Mitta River, southeastern Australia. River Research and Applications 21: Treadwell, S Patterns in community metabolism and biomass of biofilms colonising large woody debris along an Australian lowland river. PhD thesis. Monash University, Melbourne. Treadwell, S., J. Koehn, and S. Bunn Large woody debris and other aquatic habitat. Pages in S. Lovett and P. Price, editors. Riparian land management technical guidelines, Volume one: Principles of sound management. Land and Water Resources and Research Development Corporation, Canberra. Trueman, W. T Some recollections of native fish in the Murray-Darling system with special reference to the trout cod: Maccullochella macquariensis. Summary and source material from the draft Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 118

120 publication - Bluenose: The lost world of the trout cod. Prepared as an Interim Report for Native Fish Australia (Victoria) Incorporated. Turnbridge, B. R A survey of the fish populations in the Mitta Mitta River and tributaries before the construction of Dartmouth Dam. Dartmouth Dam Project: Report on environmental studies. Report prepared by the State Rivers and Water Supply Commission, Melbourne for the River Murray Commission. Walker, K. F., and T. J. Hillman Limnological survey of the River Murray in relation to Albury- Wodonga, Report to the Albury-Wodonga Development Corporation. Waters, J. M., M. Shirley, and G. P. Closs Hydro-electric development and translocation of Galaxias brevipinnis: a cloud at the end of the tunnel? Canadian Journal of Fisheries and Aquatic Sciences 59: Weatherley, A. H., and J. S. Lake Introduced fish species in Australian waters. Pages in A. H. Weatherley, editor. Australian inland waters and their fauna. Australian National University Press, Canberra. Ye, Q., J. Higham, and J. Johnson Murray barrage fishway assessment program. South Australian Research and Development Institute, Aquatic Sciences. Report for the Murray-Darling Basin Commission. Ye, Q., K. J. Jones, and B. E. Pierce Murray Cod (Maccullochella peelii peelii), fishery assessment report to PIRSA for the Inland Waters Fishery Management Committee., South Australian Research and Development Institute, Adelaide. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 119

121 Appendix A Agency databases The following table lists agency databases requested and included in the project database. A comment is provided to indicate any specific issues associated with data availability, type or quality. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 120

122 State Data source Contact Comment ACT No formal database exists in ACT. Mark Lintermans provided survey data ( ). Mark Lintermans Environment ACT This data contained some catch effort information NSW NSW Fisheries data base ( ) DSE Aquatic Fauna Database ( ) Bob Creese NSW Fisheries Brad Dale/Vanessa Stubbs Department of Sustainability and Environment Includes Llewelyn's surveys in and NSW Rivers survey data. No catch effort data was made available No catch effort data available. Database is not fully up to date with recent Arthur Rylah Institute data. ARI data was requested but was not made available. Victoria South Australia Queensland General MDB Primary Industries Research Victoria database ( ) Peter Grant Department of Primary Industries Catch effort data provided but many date and location fields missing and catch effort data was inconsistently recorded with respect to units of effort, number of passes etc Museum Victoria ( ) Dianne Bray/Neroli Hundson No catch effort data available Commercial fishing data ( ) Angelo Tsolos Catch data grouped into total weight and not location specific. Confidentiality restrictions apply to specific catch effort data Annual Report. Murray Barrage Fishway Assessment Program for the MDBC Qifeng Ye Catch effort data provided South Australian recreational fishing survey data ( ) Annette Doonan Catch data grouped into total weight and not location specific South Australian Museum Ralph Foster No catch effort data available Queensland Museum ( ) Jeff Johnson No catch effort data available Queensland DPI. Fisheries Long-term Monitoring Program ( ) Len Olyott / Mary Carmody Catch effort data provided Department of Natural Resources and Mines David Moffatt Data repeatedly requested but not provided Sustainable River Audit ( ) Greg Long (MDBC) Catch effort data provided Tri-State Murray River Fish survey ( ) Lee Baumgartner NSW Fisheries Catch effort data provided Australian Museum ( ) Mark McGrouther No catch effort data available Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 121

123 Appendix B Other data sources The following data sources and reports were reviewed and where data was available that was not otherwise present in agency databases (see Appendix A) it was included in the project database. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 122

124 ARI (2005) National recovery plan for the trout cod, Maccullochella macquariensis Annual Report. Department of Sustainability and Environment, Victoria. Baxter, A. (1985). Trout Management Group fish population surveys, ; location of sampling sites and fish species caught. Technical Report Series No. 15. December Department of Conservation, Forests and Lands, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria. Bertozzi, T., Adams, M., and Walker, K.F. (2000). Species boundaries in Carp Gudgeons (Eleotrididae: Hypseleotris) from the River Murray, South Australia: evidence for multiple species and extensive hybridization. Marine and Freshwater Research 51: Bishop, K.A., and Harris, J.H. (1990). Effects on fish of the proposed enlargement of Chaffey Dam. NSW Fisheries Research Institute report to the NSW Department of Water Resources Bond, N.R., and Lake, P.S. (2005). Ecological Restoration and Large-Scale Ecological Disturbance: The Effects of Drought on the Response by Fish to a Habitat Restoration Experiment. Restoration Ecology 13: (Note All Granite Creeks project data provided by N Bond) Brown, P. (1992). Occurrence of a neosilurid catfish Neosilurus sp. in the Paroo River, Murray- Darling Basin. Proceedings of the Linnean Society of New South Wales 113: Brown, P., McKinnon, L., and Strongman, R. (1997). A preliminary assessment of fish passage at Rice's Weir fishway, November Report prepared by Marine and Freshwater Resources Institute for Fisheries Victoria and the Lower Goulburn Waterways Management Authority. Brown, P., McKinnon, L., Gasior, R., and Douglas, J. (1997). Broken Creek pre-fishway assessment, March-April Report prepared by Marine and Freshwater Resources Institute for Fisheries Victoria. Brumley, A.R. (1987). Past and present distributions of Golden Perch Macquaria ambigua (Pisces: Percichthyidae) in Victoria, with reference to releases of hatchery produced fry. Proceedings of the Royal Society of Victoria 99: Brumley, A., Morison, A.K., and Anderson, J. (1987). Revision of the conservation status of several species of warmwater native fish. After surveys of selected sites in Northern Victoria ( ). Technical Report Series No. 33. February Department of Conservation, Forests and Lands, Fisheries Division, Kaiela Fisheries Research Station. Arthur Rylah Institute for Environmental Research, Shepparton, Victoria. Cadwallader, P.L. (1977) J.O. Langtry s Murray River Investigations. Fisheries and Wildlife Paper, Victoria 13: 70 pp. Victorian Government Printer, Melbourne Cadwallader, P.L. (1979) Distribution of native and introduced fish in the Seven Creeks River system, Victoria. Australian Journal of Ecology 4: 361:385 Cadwallader, P.L. and Backhouse, G.N (1983) Past and present distribution and translocations of Murray cod Maccullochella peelii and trout cod M. macquariensis (Pisces: Percichthyidae) in Victoria. Proceedings of the Royal Society of Victoria 96 (1): Cadwallader, P.L. (1981). Past and present distributions and translocations of Macquarie Perch Macquaria australasica (Pisces: Percichthyidae), with particular reference to Victoria. Proceedings of the Royal Society of Victoria. 93: Chessman, B., and Williams, W.D. (1974). Distribution of fish in inland saline waters in Australia. Australian Journal of Marine and Freshwater Research 25: Close, P (2002) An Assessment of the Environmental Flow Requirements for Seven Creeks, Victoria: A Component of the Seven Creeks Stream Flow Management Plan. A Report for Goulburn-Murray Water. Department of Natural Resources and Environment. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 123

125 Close, P and G, Aland (2001) The impact of instream barriers on fish assemblages in lower reaches of the Broken River and Seven Creeks, and preliminary assessment of fish passage through the Euroa Town and Lake Benalla fishways. Department of Natural Resources and Environment Copeland, C., Schooneveldt-Reid, E., and Neller, S. (2003). Fish Everywhere - an oral history of fish and their habitats in the Gwydir River. NSW Fisheries. Curmi, T.J (1996) Habitat use and diet of River blackfish (Gadopsis marmoratus) and Two-spined blackfish (Gadopsis bispinosus) in Tallangatta Creek. Hons. Thesis. LaTrobe University, Bundoora Davis, T.L.O. (1977). Age determination and growth of the freshwater catfish, Tandanus tandanus Mitchell, in the Gwydir River, Australia. Australian Journal of Marine and Freshwater Research 28: Douglas, J., Gooley, G., Kemp, D., and Ingram, B. (1998). An ecological survey of three major Murray River anabranches in North-Western Victoria with reference to Ecosystem Condition Indices. Marine and Freshwater Resources Institute, Alexandra Gilligan, D. (2005). Fish communities of the Murrumbidgee catchment: Status and trends. NSW Department of Primary Industries - Fisheries Final Report Series No. 75, Narrandera Fisheries Centre, Narrandera, NSW. Gilligan, D. (2005). Fish communities of the Lower Murray-Darling catchment: status and trends. NSW Department of Primary Industries - Fisheries Final Report Series No. 83, Narrandera Fisheries Centre, Narrandera, NSW. Gilligan, D., Rodgers, M., Breheny, K., Wooden, I., Bruce, A., Creese, B., and Schiller, C. (2002). Downstream transport of larval and juvenile fish. Draft report. NRMS Project No. R799. NSW Fisheries Report Series, NSW Fisheries Office of Conservation, Narrandera Fisheries Centre, Narrandera, NSW. Hardie, S.A. (2000). Examination of fish and invertebrate fauna in seven lakes in the Swan Hill - Kerang Region, Northern Victoria. Department of Natural Resources and Environment, Victoria. Harris, J.H., Edwards, E.D., and Curran, S.J. (1992). Bourke Weir fish passage study. NSW Fisheries Research Institute, Cronulla, NSW. Khan, M.T, Khan, T.A and Wilson, M.E (2004) Habitat use and movement of river blackfish (Gadopsis marmoratus R.) in a highly modified Victorian stream, Australia. Ecology of Freshwater Fish. 13: Koster, W.M., Crook, D., and Faribrother, P. (2004). Surveys of fish communities in the lower Goulburn River. Annual report 2003/2004. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Victoria. Lake, J.S. (1967). Principal fishes of the Murray-Darling River system. Pages In A.H. Weatherley, editor. Australian inland waters and their fauna. Australian National University Press, Canberra. Lake, J.S. (1967). Freshwater fish of the Murray-Darling River system. New South Wales State Fisheries Research Bulletin 7: 48 pp. Lintermans, M (1998) The ecology of two-spined blackfish Gadopsis bispinosus (Pisces: Gadopsidae). Msc. Sci. Australian National University Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 124

126 Lintermans, M. (2000). Recolonization by the Mountain Galaxid Galaxias olidus of a montane stream after the eradication of Rainbow Trout Oncorhynchus mykiss. Marine and Freshwater Research 51: Lintermans, M. (2000). The Status of Fish in the ACT: A Review of Current Knowledge and Management Requirements Environment ACT, Canberra Lintermans, M. (2003). The successful re-establishment of the endangered fish, Macquarie Perch, Macquaria australasica, in the Queanbeyan River, New South Wales. Cooperative Research Centre for Freshwater Ecology, Canberra, ACT. Lintermans, M and Rutzou (1990) A new locality for the two-spined blackfish (Gadopsis marmoratus) outside Victoria. Victorian Naturalist. 107:26-27 Lintermans, M., and Rutzou, T. (1990). The fish fauna of the Cotter River catchment. Research report 4. ACT Parks and Conservation Service, Canberra. Lewellyn, L. (1974). Spawning, development and distribution of the Southern Pygmy Perch, Nannoperca australis Gunther, from inland waters in eastern Australia. Australian Journal of Marine and Freshwater Research 25: Llewellyn, L. (1979). Some observations on the spawning and development of the Mitchellian Freshwater Hardyhead Craterocephalus fluviatilis McCulloch from inland waters in New South Wales. Australian Zoologist 20: Llewellyn, L. (1983). The distribution of fish in New South Wales. Australian Society for Limnology Special Publication 7: 70. Lloyd, L.N., and Walker, K.F. (1986). Distribution and conservation status of small freshwater fish in the River Murray, South Australia. Transactions of the Royal Society of South Australia 110: Mallen-Cooper, M and Brand, D (1992) Assessment of two fishways on the River Murray and historical changes in fish movement. Report to the Murray-Darling Basin Commission Mallen-Cooper, M., Stuart, I., Hides-Pearson, F., and Harris, J. (1995). Fish migration in the Murray River and assessment of the Torrumbarry fishway: final report. New South Wales Fisheries Research Institute, Sydney. McKinnon, L.J. (1993). A significant record of the endangered Trout Cod, Maccullochella macquariensis (Pisces: Percichthyidae) made during fish surveys of the Barmah Forest, Victoria. Victorian Naturalist 110: McKinnon, L.J., and Shepheard, N. (1995). Factors contributing to a fish kill in Broken Creek. Victorian Naturalist 112: Meredith, S., Gawne, B., Sharpe, C., Whiterod, N., Conallin, A., and Zukowski, S. (2002). Dryland floodplain ecosystems: influence of flow pattern on fish production. Final report to Department of Agriculture, Fisheries, Forestry - Australia. Murray-Darling Freshwater Research Centre, Lower Basin Laboratory, Mildura, Victoria. Morison, A.K., and Anderson, J.R. (1987). Status of Trout cod Maccullochella macquariensis, Macquarie perch Macquaria australasica, and other fish populations in the upper reaches of Seven Creeks, based on surveys between 1981 and Kialla Fisheries Research Station, Department of Conservation, Forests and Lands, Fisheries Division, Shepparton, Victoria. Mallen-Cooper, M., Stuart, I., Hides-Pearson, F., and Harris, J. (1995). Fish migration in the Murray River and assessment of the Torrumbarry fishway: final report. New South Wales Fisheries Research Institute, Sydney. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 125

127 Puckridge, J.T., and Walker, K.F. (1990). Reproductive biology and larval development of a Gizzard Shad, Nematalosa erebi in the River Murray, South Australia. Australian Journal of Freshwater and Marine Research 41: Reynolds, L.F. (1983). Migration patterns of five fish species in the Murray-Darling River system. Australian Journal of Marine and Freshwater Research 34: Rowland, S.J. (1989). Aspects of the history and fishery of the Murray Cod, Maccullochella peeli (Mitchell) (Percichthyidae). Proceedings of the Linnean Society of New South Wales 111: Saddlier, S, Crowther, D, and Papas, P (2002). Aquatic fauna and habitat structure of Seven Creeks: status of pre and post-rehabilitation works condition Scott, A. (2005). Historical evidence of native fish in the Murray-Darling Basin at the time of European settlement - from the diaries of the first explorers. CRC for Freshwater Ecology, Canberra, ACT. Sinclair Knight Merz fish survey data (Murray River and Northern Victorian tributaries, ) Swales, S., Curran, S.J., and West, J. (1993). A survey of the fish resources of Cudgegong River, April NSW Fisheries Research Institute report to the NSW Department of Water Resources. Swales, S., and Curran, S.J. (1995). Pindari Dam enlargement study fish population investigations. NSW Fisheries Research Institute report to the NSW Department of Land and Water Conservation. Swales, S., and Curran, S.J. (1995). Survey of the fish resources of the Macquarie Marshes. NSW Fisheries Research Institute report to the NSW Department of Water Resources. Turnbridge, B.R. (1978). A survey of the fish populations in the Mitta Mitta River and tributaries before the construction of Dartmouth Dam. In Dartmouth Dam Project: Report on environmental studies. Report prepared by the State Rivers and Water Supply Commission, Melbourne for the River Murray Commission. Walker, K.F., and Hillman, T.J. (1977). Limnological survey of the River Murray in relation to Albury-Wodonga, Report to the Albury-Wodonga Development Corporation. Ye, Q., Jones, K.J., and Pierce, B.E. (2000). Murray Cod (Maccullochella peelii peelii), fishery assessment report to PIRSA for the Inland Waters Fishery Management Committee. South Australian Research and Development Institute, Adelaide. Ye, Q., Higham, J., and Johnson, J. (2002). Murray barrage fishway assessment program. South Australian Research and Development Institute, Aquatic Sciences. Report for the Murray- Darling Basin Commission. Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 126

128 Appendix C Workshop attendees Workshop 1. Preliminary data review and assessment Mark Lintermans, MDBC Dean Gilligan, NSW Fisheries Qifeng Ye, SARDI SA Leonard Olyott, DPI QLD Peter Grant, DPI VIC Workshop 2. Final data review and confirmation of approach Mark Lintermans, MDBC Dean Gilligan, NSW Fisheries Wayne Robinson, University Sunshine Coast Peter Jackson Qifeng Ye, SARDI SA Paul Hardiman, DEWR Belinda.Cant, DSE Yung En Chee, Melbourne University Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 127

129 Appendix D Distribution map for selected species D.1 Murray Hardyhead Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 128

130 D.2 Mountain galaxias Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 129

131 D.3 Trout cod Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 130

132 D.4 Macquarie perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 131

133 D.5 Southern pygmy perch Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 132

134 D.6 Flat-headed gudgeon Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 133

135 D.7 Freshwater catfish Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 134

136 D.8 Carp Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 135

137 D.9 Eastern gambusia Introduced Fish:Reports:MD34 SKM 2008 MDB fish datasets analysis final project report.docx PAGE 136