Carp Reduction Measures

Transcription

1 5. Carp Reduction easures Before proceeding to examine and recommend specific site-based interventions there are some over-arching issues that also form part of this Plan. These are: 5.1 Promoting community engagement; Addressing priority knowledge gaps; and, Operating policy or regulatory 'levers' to assist carp control. Promoting community engagement Under the UDR project there is a separate Communication, Education, Participation and Awareness (CEPA) Plan. This recognises that any improvement in the condition of the UDR and its tributaries can only occur if the associated communities are fully engaged and committed to helping to achieve the objectives. Carp are particularly abundant throughout Lake Burley Griffin, Jerrabomberra wetland, the lower reaches of the olonglo River and the Queanbeyan River. An annual 'carp out' event around Lake Burley Griffin attracts huge interest. This year (2010), 2,049 people registered to fish and a total of 691 carp (1,256 kg) and 883 (164 kg) of Redfin were caught in the day see Plates 17 and 18 below). Plates 17 and 18: The 2010 Canberra Carp Out held at Lake Burley Griffin. Photographs: Bill Phillips To ensure positive involvement by the community, the CEPA Plan has been carefully developed and targeted. It also takes into account the priorities recognised in this Carp Reduction Plan. Rather than repeat here all the relevant contents of the CEPA Plan it is recommended that readers consult it to identify the full range of carp-related engagement and awareness raising actions that are considered priorities. Where actions specified in the following sections contain some element of community engagement they are denoted with the superscript CE 43

2 5.2 Addressing priority knowledge gaps Knowing the problem is the first step to solving it. A significant limiting factor with the development of this Plan has been the knowledge gaps. A lack of detailed knowledge of carp distribution across the region, local habitat preferences and population dynamics has meant that 'educated' guesses have had to be made based on research findings in other locations, local knowledge and knowledge gained from historical biological survey work in the region It is vital in order to ensure the measures recommended below in Sections 5.4 are scientifically well-founded, that long-term and rigorous monitoring of the native and pest fish populations in and associated with the UDR is undertaken. The collection of baseline data is critical to the overall success of the plan because it assists in determining if the outputs and outcomes are being achieved by providing a measure of change against the present. Further investigations across the region are also needed to help understand the ecology of carp. In particular, information is urgently needed on habitat use, breeding hotspots and broader movement patterns, especially between habitats such as preferred breeding locations. Knowing these details will enable actions to be targeted at carp during susceptible stages of their lifecycle and this will greatly increase the chances of success (see Figure 3). In addition, there are some waterbodies in the UDR region that are currently believed to be carp-free. The most notable are the Cotter catchment upstream of Cotter dam, and Googong Reservoir on the Queanbeyan River. There are a number of other ACT rivers where carp are currently absent. These include the Naas, Orroral and Tidbinbilla rivers, and the majority of the Gudgenby River (Lintermans 2000). It is much less expensive to keep an area carp-free than it is to try and remove carp at a later date. In some of these locations the barrier that prevents invasion by carp is obvious but for others it is not. In the Cotter and Googong cases it is the physical barrier provided by the dam wall. Should carp breach these barriers (for whatever reason) this would have significant impacts on carp management in the UDR and surrounding region with priorities and resources for carp management having to be reviewed. A priority is to gain a better understanding of those areas where carp are not found currently and what steps are required to keep them this way. The knowledge gaps identified as priorities are presented in Table 3. Table 3: Addressing priority knowledge gaps Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) 1. Support the further analysis and publication of existing fish survey data of the region and summary of findings on population structure and age classes Reports documenting survey and monitoring programs completed. Improved knowledge of carp distribution and abundance ACT PC&L University of Canberra 2. Undertake a survey of carp populations in the region to collect up to date information about age classes, population structure and habitat use. Reports and population model completed. Improved knowledge of carp dynamics leading to better targeting of management actions ACT PC&L, I&I NSW, Universities 44

3 Table 3 continued. Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) 3. Confirm those areas where carp are not currently present and why. Notably the Naas and Orroral rivers and parts of the Gudgenby River. Confirmation of carp distribution across the region. Improved knowledge for prioritisation of management activities ACT PCL, I&I NSW, Uni of Canberra, Anglers 4. Identify aggregation sites, CE when spawning activity occurs and what are the cues or triggers for breeding. Documentation of aggregation sites and related information about spawning. Targeted management interventions at carp breeding hotspots ACT PCL, I&I NSW, Uni of Canberra, Anglers 5. Track movement patterns within and between the management units (see Section 5.4). ovement patterns documented. Improved management as movement of fish between management units is clarified ACT PCL, I&I NSW, Universities 6. Investigate habitat use by carp across the region. CE Reports detailing habitat use, preferences, seasonal patterns etc. Improved targeting of habitats for carp control ACT PCL, I&I NSW, Universities 7. Undertake carp larval sampling to locate 'hot spots' or core source populations. 'ot spots' or core source populations. Improved targeting of habitats for carp control 2015 ACT PCL, I&I NSW, Universities 8. Establish the role of the urban ponds and lakes as sources of carp re-infestation of the UDR. Role of the urban ponds and lakes as sources of carp reinfestation established and documented. Improved targeting of habitats for carp control ACT PCL, I&I NSW, Universities 9. Investigate if there are carp refugia (such as farm dams) from which re-infestations are being sourced. Studies into possible carp refugia (such as farm dams) completed. Improved targeting of control activities ACT PCL, I&I NSW 10. Establish if there are winter aggregation sites, such as thermal refuges, which could be targeted. Investigations into possible winter aggregation sites completed. Improved targeting of control activities 2015 ACT PCL, Universities 11. If existing or new fishways are operated to help intercept carp (see Sections 4.4-7) determine what impact this has on native fish passage. Studies completed on impacts of fishways operated for carp interception. Better designs for fishways, or altered fishway operating protocols. Dependant on whether fishways are utilised for carp control. ACT PCL, I&I NSW, Universities 12. If intensive carp removal is undertaken in conjunction with native fish stocking and habitat improvements in urban ponds, monitor the impact this has on carp re-infestation. onitoring results collected and analysed. Improved carp management including cost benefit analysis ACT PCL, I&I NSW, Universities, Capital Region Fishing Alliance CE 45

4 5.3 Operating policy or regulatory 'levers' to assist carp control Also identified at a generic level are several policy or regulatory 'levers' that it is recommended be pursued. Summary information is provided below and Table 4 sets out the actions proposed Exemptions under legislation for coarse fishing tournaments Current ACT Government practice is to allow some exemptions under the Fisheries Act 2000 for organised coarse fishing competitions on Canberra's urban lakes. Such competitions value the condition of captured fish, and they are released alive at the end of the tournament. These tournaments have often resulted in the capture and release of several tonnes of carp. Such exemptions clearly conflict with the intent of this Carp Reduction Plan. In NSW there are similar issues with it not being illegal to return carp to the waterway after capture Review of the grey list for possibly noxious species The Strategic Approach to the anagement of Ornamental Fish in Australia (NRC 2007) lists European carp as a noxious species nationally. owever, in the same report Koi carp (the same species as European carp) is included on the grey list of species requiring further scientific/technical consideration and risk assessment. Such a situation where the same species is listed in two different categories is clearly untenable from a management perspective, particularly when more than 70% of carp examined from Lake Burley Griffin in a genetics study exhibited Koi genetic signatures (Davis 1996; Davis et al. 1998), and yet were visually indistinguishable from normal wild carp. The 'grey' list is currently under review, and it is recommended that Koi carp to be listed as noxious also The keeping of Koi carp Current ACT practice is to allow the keeping of Koi carp by hobbyist, including in outside ponds. This can be problematic, given that many outside ponds are adjacent to natural drainage lines, and that high rainfall events may lead to overflow and escape of Koi carp into the wild. The invasion of Koi carp into some northern NSW coastal rivers has been attributed to their escape from outside ponds (I&I NSW 2009). Keeping of Koi carp in outside ponds is still legal in NSW, despite carp being listed as a noxious species Implementation of provisions in the ACT's Pest Plants and Animals Act 2005 In 2005 the ACT's Pest Plants and Animals Act was introduced. This legislation contains provisions to declare an animal as a pest, and to also categorise it as either a notifiable pest animal (a pest animal whose presence must be notified to the chief executive) or a prohibited pest animal (a pest animal whose supply or keeping is prohibited). Carp are currently declared as a pest animal under this Act, but are not listed as either notifiable or prohibited. Declaring an animal to be a notifiable pest animal requires landholders to notify the relevant authority with two working days of the presence of such a pest. This potentially allows for carp to be declared a notifiable pest animal in specific sub-catchments that are currently carp-free, and would greatly improve the reporting of carp invasion of such catchments in the future. The issue of who should pay for such removals will need to be addressed as some landholders may be reluctant to notify authorities if they would then be responsible for removing carp from their waterbody. The Act also contains provisions where the minister may require the preparation of a pest animal management plan for the management of a pest animal. A pest animal management plan may outline requirements for the following, having regard to the potential threat and the practicality of control measures: 46

5 (a) managing the environmental and agricultural impact of a pest animal in a cost effective way if its eradication is impractical; (b) controlling potential sources of invasion through trade, transport and escape from urban areas. In NSW carp are currently listed as a Class 3 noxious species under the Fisheries anagement Act 1994, allowing them to sold and possessed. This listing recognises the fact that wild carp are a commercial fisheries species and Koi carp are an important ornamental fish, but it aims, through education and awareness raising to discourage further spread of carp. Currently it is not illegal for recreational fishers to immediately return carp to the water where they were captured; however, Industry and Investment NSW strongly encourages anglers to retain and utilise them Closures to recreational fishing in specific locations There are currently a number of closures to recreational fishing in the ACT under its Fisheries Act The most important of these to carp management is the closure of Cotter Reservoir and the Cotter River and all its tributaries upstream of the Bendora dam wall. The entire Cotter catchment upstream of the Cotter dam wall is currently carp-free (Lintermans 2000) and considerable effort is being directed to ensuring that the integrity of the Cotter dam wall as a barrier to invasion by both carp and Redfin perch is maintained (ACTEW Corporation 2009a,b). If recreational fishing were allowed in these locations in the future, then the likelihood of carp being introduced as baitfish increases significantly, as the introduction and spread of alien fish through bait bucket introductions is an acknowledged problem worldwide (Lintermans 2004; Litvak and andrak 1993; Ludwig and Leitch 1996). Opening of the Cotter Reservoir to recreational fishing would also increase pressure to stock the reservoir with recreational angling species, and contaminants of alien species in stocking programs has been well established (Lintermans 2004) Policy on stocking of native fish The current ACT fish stocking policy does not allow the stocking of native fish for recreational purposes in the ACT's rivers and streams, unless it is part of a recognised research program or for conservation purposes (ACT Government 2009). This allows the abundance of native fish detected in regular fish monitoring programs in ACT streams to be used as a barometer of stream or fisheries 'health' (Lintermans 2002). A change to this policy would potentially have implications for any monitoring program established under this Carp Reduction Plan because it is not currently practical to distinguish stocked fish from wild fish. Industry and Investment NSW supports several Departmental and community fish stocking programs through research and the Dollar for Dollar Native Fish Stocking Program (funded through the NSW Recreational Fishing Trust). Stocking activities are managed in accordance with the Freshwater Fish Stocking Fishery anagement Strategy. The priority policy or regulatory 'levers' to assist Carp control are presented in Table 4. 47

6 Table 4: Operating policy or regulatory 'levers' to support carp control Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) 1. Review the anomaly which allows an exemption under the Fisheries Act 2000 for coarse fishing competitions to return live carp back to Canberra's lakes. Review completed and provided to appropriate decision makers. Policy and practice on coarse fishing aligns with objectives of this plan ACT PCL 2. As part of the current review of the national 'grey' list of possibly noxious species, seek to have Koi carp recognised as noxious along with the related 'European' carp. Review recommends Koi carp recognised as noxious along with Carp. Carp and Koi carp are recognised as a single species and managed as such ACT PCL, I&I NSW 3. Both the NSW and ACT governments are urged to ban the keeping of Koi carp in outside ponds consistent with the above action. Both Governments ban the keeping of Koi carp in outside ponds. Cross-border consistency in carp management and reduced risk of escapes to the wild ACT PCL, I&I NSW 4. Declare Carp as a 'notifiable pest animal' under the ACT's Pest Plants and Animals Act 2005 Declaration of Carp as a 'notifiable pest animal' completed. Improved surveillance of those waters currently carpfree. Faster response times to new incursions 2012 ACT PCL 5. Continue the exclusion of recreational angling in the Cotter Reservoir and the Cotter River and all its tributaries upstream of the Bendora dam wall. Exclusion continues. elping to maintain the Cotter catchment upstream of the Cotter dam wall as carp-free. Improved protection of Cotter river fish community. Ongoing ACT PCL 6. Continue the current ACT government policy of not allowing the stocking of native fish for recreational purposes in ACT rivers and streams, unless it is part of a recognised research program or is for conservation purposes. Policy continues. aintenance of consistent picture of the health of the native fish community On-going ACT PCL 7. Review NSW stocking activities within the geographical scope of this plan, in consultation with local fishing groups and other government and nongovernment stakeholders. Document current practices. Avoid policy inconsistencies between the ACT and NSW I&I NSW, Fishing groups, urrumbidgee CA and others 48

7 5.4 Site-specific interventions In the UDR and surrounding waterways, the Carp Reduction Plan aims for controlled reductions; with complete eradication impossible given currently available methods. This Plan also assumes that the other measures envisaged under the UDR Implementation Plan will be undertaken (see Section 4.1) and that these will see improvements to in-stream and riparian habitats, water quality, native fish passage and growth in the native fish population so that these can also play a role in carp control. Table 2 (in Section 2) set out the suite of carp control options currently available, and based on these, and the way the waterways of the UDR region flow and are regulated, the following are seen as the most suitable forms of site-specific intervention. 1. Where feasible, operate existing and any future fishways on in-stream structures to provide opportunities to remove a proportion of the dispersing carp population; 2. Identify spawning sites in the lakes and wetlands, and where possible reduce breeding activity by minimising access to these by adult carp and/or removing these fish from the population; 3. Identify any other aggregation sites in the rivers, creeks and lakes, and where possible take steps to remove large numbers of carp from the population at these sites; 4. In the urban ponds apply a combination of screens, carp removal, habitat improvements and re-stocking with native fish to reduce the roles these may be playing as source for re-infestation; and, 5. Examine the possible role farm dams may be playing as a source for re-infestation of the waterways by carp (see Knowledge gaps, above). anagement units In order to assist with setting out a strategic approach, the UDR and its tributaries has been divided into management units. These are shown in Figure 20 and are as follows: anagement Units Description 1 urrumbidgee River from Bredbo to and including Angle Crossing. This also includes the Bredbo River tributary. 2 From Angle Crossing to and including Casuarina Sands. This also includes the Gudgenby, Orroral and Naas River tributaries, Tuggeranong Creek and its upstream weir and lake plus urban ponds. The Paddy's and Cotter River tributaries are also included in this management unit. 3 From Casuarina Sands to and including the junction of Ginninderra Creek with the urrumbidgee River. Also included in the unit is the olonglo and Queanbeyan Rivers, Lake Burley Griffin, Jerrabomberra Creek and wetland, Sullivan's Creek and several other drainage lines discharging into Lake Burley Griffin. Where appropriate, sub-management units have been described within these broader units to assist further targeting of actions. 49

8 Zone 1 Bredbo River Angle Crossing Gudgenby and Naas Rivers Zone 2 Upper urrumbidgee Demonstration Reach Bredbo Tuggeranong Creek, weir, lake and ponds upstream Cotter and Paddy s rivers Zone 3 Casuarina Sands olonglo River, Lake Burley Griffin, Sullivan s and Jerrabomberra Creeks (and wetland), Queanbeyan River Ginninderra Creek, lake and ponds upstream Junction of Ginninderra Creek with urrumbidgee River Figure 20: Stylised diagram showing the tributaries of the Demonstration Reach and below it extending to where Ginninderra Creek joins the urrumbidgee River (This is a repeat of Figure 6. 50

9 5.4.1 anagement Unit 1: Crossing urrumbidgee River from Bredbo to Angle The urrumbidgee River from Bredbo to Angle Crossing has significant populations of native fish, including Trout cod and acquarie perch (Lintermans 2002), while carp are also present in this part of the UDR. Where they breed and how much emigration or immigration upstream or down is not known. Gaining a better understanding of these things is vital and has been identified as a priority knowledge gap (see Table 3.). Little is currently known about the carp population in the Bredbo river. Within this unit there are no in-stream structures with fishways that might allow for the installation of carp traps. Angle Crossing (see Plates 19 and 20) is too low-level and therefore not suitable for any future consideration of a fishway with carp trap, unless the structure is upgraded in the future when this should be considered. There are also no floodplain wetlands in this upland part of the UDR that it would be expected carp might seek out as spawning areas. As part of the urrumbidgee to Googong dam water transfer project being undertaken by ACTEW at present, there is to be a pump station installed at Angle Crossing. This poses the risk of carp being transferred from the urrumbidgee to Googong Dam, which is at present carp-free. To reduce this risk, there will be a 0.5 mm mesh screen installed on the pump offtake at Angle Crossing which should exclude carp eggs and above. At this southern end of the UDR is the township of Bredbo, and engaging with this community to get their assistance with implementing this plan and providing information on carp aggregations etc is recognised as a priority in the CEPA Plan. Plates 19 and 20: Angle Crossing looking upstream (left) and downstream (right). Photo: Bill Phillips 51

10 Table 5: Actions recommended for anagement Unit 1 Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) 1. Engage with the community CE of Bredbo and surrounds to enlist their assistance with implementing this plan and providing information on carp aggregations etc. Anecdotal information that may help focus future detailed surveys and research is documented. Better understanding of carp population dynamics in this part of the UDR, and the interplay between carp in the area with upstream and downstream populations urrumbidgee CA I&I NSW Bredbo stakeholders 2. See Table 3 Knowledge gaps, especially in relation to gaining a better understanding of the carp populations in this part of the UDR and the Bredbo River. Primary biological information regarding population status and recruitment collected. Scientific data on population growth, recruitment, mortality and age applied to fine tune this plan. Ongoing I&I NSW 3. Ensure that as part of the urrumbidgee to Googong dam water transfer project being undertaken by ACTEW, the off-take of the pump station installed at Angle Crossing has a 0.5 mm mesh screen to exclude carp eggs and above, so that the currently carp-free Googong dam is kept that way. Testing of fine screening mechanisms for pump off takes completed. Recommendatio ns for screening early life-stages of carp at commercial pumping sites. Evidence that carp cannot survive the screening and pumping process. Googong Dam remains carpfree. id-2011 ACTEW ACT PC&L I&I NSW 4. If the above actions reveal opportunities for highly focussed activities to interfere with carp spawning or for community demonstration projects CE to showcase carp removal, then these should be considered in consultation with stakeholders and management agencies. Communitybased projects for demonstrating effective carp control based on sound science undertaken. Demonstrably effective carp reduction exercise in partnership with major stakeholders. Ongoing urrumbidgee CA I&I NSW 5. If at some future time a decision is taken to upgrade Angle Crossing to a road culvert crossing or similar fish passage and carp trapping should be factored into the design. Site used as demonstration site for Williams carp cage and impacts on local carp population. Demonstrably effective carp reduction exercise in partnership with major stakeholders. Dependant on available funding. ACT Government 52

11 5.4.2 anagement unit 2: Casuarina Sands urrumbidgee River from Angle Crossing to This anagement Unit includes several important tributaries (Gudgenby-Naas, Cotter-Paddy s River systems and the Tuggeranong Creek system). This management unit has been further divided into four sub-units as follows: Sub-unit 2(a): Gudgenby, Orroral and Naas Rivers Sub-unit 2(b): Cotter and Paddy's Rivers Sub-unit 2(c): urrumbidgee River, Point ut Crossing and Casuarina Sands weir and fishway Sub-unit 2(d): Tuggeranong Creek, weir, lake and related urban ponds Sub-unit 2(a): Gudgenby, Orroral and Naas Rivers In this sub-unit there are several creeks, stream and rivers. Notably, the Naas and Orroral rivers, and the majority of the Gudgenby river are carp-free (Lintermans 2000). Gaining an understanding of why carp have not as yet infested the whole system is important to help develop strategies to keep these waterways carp-free. This is a priority knowledge gap (see Table 3). Once addressed, then strategies and surveillance and rapid response systems need to be developed to keep carp from moving in. The latter may require vigilance from anglers and landholders as well as management agencies. Sub-unit 2(b): Cotter and Paddy's Rivers The Cotter River catchment upstream of Cotter dam remains carp-free, but downstream of the dam carp are present both above and below the weir on the Cotter River (immediately before it joins the urrumbidgee River) (see Plate 5) and in Paddy's River. Should carp breach the dam wall on the Cotter River this would be expected to impact on the threatened acquarie perch, Trout cod, Two-spined blackfish and urray river crayfish found in the dam and upstream. Work is underway at present to raise the height of the wall at Cotter dam and so care will need to be exercised to ensure carp are not accidentally assisted to colonise the dam and upstream during this activity. If this is detected an emergency response plan is recommended. The existing weir and fishway near where the Cotter River joins the urrumbidgee, with minor adaptation (addition of cones and guide rails etc), could be operated as a fish trap. This would have to be operated manually during anticipated peak migration times. In so doing there would be the chance to gather much-needed population data about carp (and then remove them) while also collecting information about native fish species moving through this fishway. Consideration should be given to upgrading this weir structure, with the installation of a Williams' Carp Separation cage, assuming the cost-benefit analysis justified such a step. If this occurred it could be operated more frequently and would sort the carp from other fish. Carp disposal might then become an issue as well as potential interference with the trap given that this weir is on public land and close to a picnic area. Access to this site for removing large numbers of carp is good, but there is no immediate power supply for operating lifting devices. Under anagement Sub-unit 2(c) see below is it similarly noted that any major upgrade of the Casuarina Sands weir and fishway should also factor in the installation of a Williams' Carp Separation cage. If this investment was supported and justified in ecological terms a single Williams' cage could be moved between the two sites, as a way to reduce costs. Equally, if 53

12 there was a move to install a fishway at Point ut Crossing (see below), or to elevate and upgrade Angle Crossing, provision for a Williams' trap, shared between several sites, is an option that should be considered. Installation of Williams cage traps would enable collection of baseline data concerning carp and movement patterns, biomass etc. It would be important, however, to identify the agency or community stakeholder group responsible for operating the traps and an appropriate avenue for disposal of carp. The design characteristics of a Williams cage are reasonably flexible and a concept is shown in Figure 21. The system could be manual or automated and include the latest innovations from testing in South Australia (Stuart et al. 2006, Conallin et al. 2009, Smith reference). Figure 21. ark IV Williams carp cage showing; A) the operating position used to catch and separate jumping carp (black fish symbols) and non-jumping Australian native fishes (grey fish symbols), and B) the raised position. The following elements are illustrated in each panel: 1) false lifting floor; 2) cone trap; 3) native fish exit gate; 4) non-return slide. For clarity, all mesh coverings are excluded from the diagram. 54

13 Sub-unit 2(c):urrumbidgee River, Point ut Crossing and Casuarina Sands weir and fishway In this management unit there is the road crossing at Point ut and the weir and fishway at Casuarina Sands (see Plates 8 and 9). Other than at moderate to high flows, the design of the Point ut Crossing precludes fish (native and carp) movements upriver. While the installation of a fishway at this site is considered desirable, it should also incorporate a fish trap or Williams' carp separation cage (see above). Without this, a fishway, while assisting native fish movements, would do likewise for carp, and this may not be a prudent from a carp management perspective. The existing weir and fishway at Casuarina Sands is ready-made for operation as a fish trap (cones and guide rails etc are available now). This trap would have to be operated manually during anticipated peak migration times. In so doing there would the chance to gather valuable population data about carp (and then remove them) while also collecting information about native fish species. If this were to take place it may also be an activity of interest to local anglers interested in native fish and carp management. As was noted above in relation to this site, consideration should be given to upgrading this weir structure, with the installation of a Williams' Carp Separation cage, assuming the costbenefit analysis justified such a step. Again, this could then be operated more frequently. Carp disposal may become an issue as well as potential interference with the trap given its location near the recently upgraded parklands at this site. Access to this site for removing large numbers of carp is not good, and there is no immediate power supply for operating lifting devices. Sub-unit 2(d): Tuggeranong Creek, weir, lake and related urban ponds The Tuggeranong Creek tributary drains the urban area of Tuggeranong. This drainage system includes a weir, lake and a number of urban ponds (Isabella, Upper and Lower Stranger see Plate 21 - Gordon and Point ut) designed to manage siltation and help improve water quality. The latter are described in the Plan of anagement for Canberra's Urban Lakes and Ponds (2001) as "water features" and are all used for a range of recreational activities. For the Tuggeranong Creek system the only realistic options for addressing carp through this Plan are with carp catch events (focussed on Lake Tuggeranong) to raise awareness of the problems, and with intensive carp control measures at one or more of the urban ponds. It is possible that these urban ponds are serving as spawning areas and source populations for the larger waterbodies and the UDR itself. Depending on the site(s) chosen this could become a community demonstration project whereby appropriate carp control tools are applied (water level drawdown during spawning, installation of carp screens on inlets and outlets, for example) and these are accompanied by re-stocking with native species and some habitat improvements (additional snags for example). There may also be scope for applying to the Invasive Animals CRC to pilot test pheromone traps in closed pond type systems. Such projects would help to promote the overall Carp Reduction Plan to the Canberra community. 55

14 Table 6: Actions recommended for anagement Unit 2 Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) Adoption of a surveillance and rapid response system based on community and agency cooperation. June 2011 ACT PC&L Sub-unit 2(a): Gudgenby, Orroral and Naas Rivers 1. It is a priority knowledge gap (see Table 3) to establish why carp have so far not been able to infest the Naas and Orroral rivers and only part of the Gudgenby river. Once addressed, then strategies and a surveillance system need to be developed to keep carp from moving in. The latter may require vigilance from anglers and landholders CE as well as management agencies. Understanding gained of the factors that inhibit or promote carp invasion. Sub-unit 2(b): Cotter and Paddy's Rivers 2. Extreme vigilance is required during the current work to raise the height of the wall at Cotter dam to ensure carp are not accidentally assisted to colonise the dam and upstream. If this is detected an emergency response is required to protect the threatened species found there (acquarie perch, Trout cod, Two-spined blackfish and urray river crayfish). Integrated surveillance monitoring and rapid response systems in place and functioning. Cotter Dam kept carp-free with robust native fish population. Jun 2011 ACT PC&L Research institutions 3. Undertake minor adaptations (addition of cones and guide rails etc) to the fishway on the existing weir on the Cotter River near where it joins the urrumbidgee. Then operate it manually during anticipated peak migration times to gather muchneeded population data about carp (and then remove them) while also collecting information about native fish species moving through this fishway. Carp monitoring and removal system operating. Important data gathering relating to native fish and carp movements informing further control planning. Jun 2011 ACT PC&L ACTEW 4. Undertake cost-benefit analysis to establish if upgrading the Cotter weir structure, with the installation and operation of a Williams' Carp Separation cage should proceed. If indicated, seek to undertake works. Cost-benefit analysis. Determined by cost-benefit analysis. Jun 2011 ACT PC&L ACTEW 56

15 Table 6 continued. Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) Sub-unit 2(c): urrumbidgee River, Point ut Crossing and Casuarina Sands weir and fishway 5. Pursue installation of a fishway at Point ut (road) Crossing incorporating a fish trap or Williams' carp separation cage (see above). Without this, a fishway, while assisting native fish movements, would do likewise for carp, and this may not be prudent from a carp management perspective. Carp monitoring and removal system installed and operating. Excellent location for removing carp and monitoring native fish. Data concerning carp movement rates and timing gained. Required if road crossing is upgraded. ACT Government ACTEW 6. Commence operating the existing fishway at Casuarina Sands during anticipated peak migration times CE. This will help gather valuable population data about carp (and then remove them) while also collecting information about native fish species. Important information on carp and native fish movements collected. Practical carp removal with minimal impacts on native fish. Beginning in 2011 annually thereafter. ACT PC&L Fishing club and other volunteers 7. Undertake cost-benefit analysis to establish if upgrading the Casuarina Sands weir structure, with the installation and operation of a Williams' Carp Separation cage should proceed. If indicated, seek to undertake works. Practical carp removal system with minimal impacts on native fish. Important information on carp and native fish movements. Removal rates of carp at a population level. By no later than 2012 to enable incorporation into design phase ACT Government 8. Related to the above, should the opportunity arise to install Williams' traps on two or more instream structures this could be made to standardised specifications and then rotated between the various sites. This would save on costs of construction. Transferable trap constructed. Ability to move cages among sites depending on carp biomass and support logistics as above ACT PC&L 57

16 Table 6 continued. Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) Sub-unit 2(d): Tuggeranong Creek, weir, lake and related urban ponds 9. As part of the CEPA Plan for the UDR encourage carp catch events focussed on Lake Tuggeranong. CE Cooperative angler events to remove adult carp and raise awareness. Increased community awareness of carp and support for on-ground actions. Annually from 2010 onwards. ACT PC&L RiverSmart Australia Recreational fishing clubs 10. Support the establishment of urban pond rehabilitation demonstration sites CE. Depending on the site(s) appropriate carp control tools would be applied (water level drawdown during spawning, installation of carp screens on inlets and outlets, for example) and these actions would be accompanied by re-stocking with native species and some habitat improvements (additional snags for example). Demonstration of carp control technologies some proven and some in development. Significant change to key local habitat and native fish values ACT PC&L Recreational fishing clubs Plate 21: Upper Stranger Pond. Photograph. Bill Phillips 58

17 5.4.3 anagement Unit 3: urrumbidgee River from Casuarina Sands to the junction of Ginninderra Creek with the urrumbidgee River anagement Unit 3 takes in the urrumbidgee River from Casuarina Sands to the junction with Ginninderra Creek on the northern side of Canberra. Also included in the unit are the olonglo and Queanbeyan Rivers, Lake Burley Griffin, Jerrabomberra Creek and wetland, Sullivan's Creek and several other drainage lines discharging into Lake Burley Griffin. This management unit has been further divided into three sub-units as follows: Sub-unit 3(a): urrumbidgee River from Casuarina Sands to the junction with Ginninderra Creek Sub-unit 3(b): olonglo River, Lake Burley Griffin, and it's tributaries, Jerrabomberra Creek and wetland and the Queanbeyan River up to Googong dam. Sub-unit 2(c): Ginninderra Creek and Falls, Lake Ginninderra, Gunghalin Pond, Yerrabi Pond and other urban ponds in Belconnen. Sub-unit 3(a): urrumbidgee River from Casuarina Sands to the junction with Ginninderra Creek. Below Casuarina Sands the only in-stream structure is Uriarra Crossing which offers no opportunities for carp control at present. Not far below this road crossing, the olonglo River joins the urrumbidgee and immediately upstream on the olonglo is the Lower olonglo Treatment Plant. The discharge from this, Canberra largest treatment plant, does impact on water quality in this part of the urrumbidgee but it is not known if this has positive or negative repercussions for either native species or carp. There are no activities recommended for this management sub-unit at present. Sub-unit 3(b): olonglo River, Lake Burley Griffin, and it's tributaries, Jerrabomberra Creek and wetland and the Queanbeyan River up to Googong dam. Scrivener Dam on the olonglo River created Lake Burley Griffin in This large dam creates an obstruction for fish (native and carp) movement upstream from the urrumbidgee River (see Plate 14). A few kilometres downstream from Scrivener Dam work has commenced (June 2010) for the new sub-division of olonglo. These new suburbs will have an urban lake to protect the olonglo and urrumbidgee Rivers from run-off, and for amenity uses. The design of the structures creating the proposed new lake impoundment and the lake habitat need to be developed with carp control and native fish needs in mind. Lake Burley Griffin has creek tributaries such as Sullivan's Creek plus a number of urban stormwater inlets. Discharging into Lake Burley Griffin is also Jerrabomberra Creek; doing so via a floodplain wetland system (see Plate 15). The olonglo River upstream of Lake Burley Griffin also has several tributaries, the largest of these being the Queanbeyan River. This river has a large dam upstream of Queanbeyan which creates Googong Reservoir. In the central urban area of Queanbeyan there are two small weirs; neither with a fishway (see Plates 22 and 23). Carp are abundant throughout Lake Burley Griffin, Jerrabomberra wetland, the lower reaches of the olonglo River and the Queanbeyan River. They are found both above and below olonglo Gorge near Queanbeyan despite the rocky terrain and river form. At present there are no weirs with fishways that would allow opportunities for carp trapping on any of these rivers. 59

18 Plates 22 and 23: Weirs near the centre of Queanbeyan on the Queanbeyan river. Photograph: Bill Phillips There is anecdotal information suggesting several locations around Lake Burley Griffin where large numbers of carp have been observed, either during the spring (so it is assumed these are spawning aggregations) or at other times of the year. Jerrabomberra Creek and its flood runner across the floodplain are also a well documented aggregation point. On the Queanbeyan River above the two weirs in the urban areas, local anglers speak of large numbers of carp and these are easily observed. Apart from the monitoring and data gathering recommended under knowledge gaps above, the opportunities to undertake carp control actions in this management sub-unit are as follows: Ensure that design of the new urban lake for the olonglo sub-divisions takes into account carp control and native fish passage. Continue supporting 'carp out' events but aim to use these for data collection (otolith collections etc) as well as community engagement. Pursue opportunities for targeted carp removal at identified 'hot spots' (spawning or thermal aggregations), like the mouth of Sullivan's creek, Jerrabomberra Creek and wetland, Queanbeyan river and others identified through more intensive surveys. Sub-Unit 3(c): Ginninderra Creek and Falls, Lake Ginninderra, Gunghalin Pond, Yerrabi Pond and other urban ponds in Belconnen. The Ginninderra Creek tributary drains the urban areas of Belconnen and Gunghalin. Like the situation with Tuggeranong Creek (see above), this drainage system includes a weir, lake and a number of urban ponds (Gunghalin Pond, Yerrabi Pond, Dunlop Ponds 1 and 2, West Belconnen Pond) designed to manage siltation and help improve water quality. The latter are described in the Plan of anagement for Canberra's Urban Lakes and Ponds (2001) as "water features" and are all used for a range of recreational activities. For the Ginninderra Creek system the options for addressing carp through this Plan are with: carp catch events (focussed on Lake Ginninderra or in the small wetland long the creek itself) to raise awareness of the problems and collect bio-data; 60

19 a possible carp trap at the upstream end of Lake Ginniderra to intercept spawning carp; and, intensive carp control measures as a demonstration site at one or more of the urban ponds. These urban ponds may be serving as spawning areas and source populations for the large waterbodies and the UDR (investigating this is a priority knowledge gap). Depending on the site(s) chosen these could become a community demonstration projects whereby appropriate carp control tools are applied (water level drawdown during spawning, installation of carp screens on inlets and outlets, for example) and these are accompanied by re-stocking with native species and some habitat improvements (additional snags for example). Such projects would help to promote the overall Carp Reduction Plan to the Canberra community. Table 7: Actions recommended for anagement Unit 3 Actions Priority Sub-unit 3(a): Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) urrumbidgee River from Casuarina Sands to the junction with Ginninderra Creek 1. There are no activities recommended for this management sub-unit at present. Sub-unit 3(b): olonglo River, Lake Burley Griffin, and it's tributaries, Jerrabomberra Creek and wetland and the Queanbeyan River up to Googong dam 2. The design of the structures to create the new lake impoundment associated with the subdivision of olonglo (downstream of Scrivener dam) needs to be developed with carp control (and fish passage) in mind. New structures and fishways designed for native fish and ability to control and remove carp. Efficient structures for carp removal with minimal human intervention in place and operational. As new impoundment infrastructure is developed. ACT Government 3. Continue supporting 'carp out' events (around Lake Burley Griffin and on the Queanbeyan River) CE but aim to use these for data collection (otolith collections etc) as well as community engagement. Cooperative angler events to remove adult carp and collect baseline demographic data. Increased community awareness of carp and ongoing thereafter. urrumbidgee CA olonglo Catchment Group Queanbeyan City Council RiverSmart Australia Fishing clubs I&I NSW 4. Pursue opportunities for targeted carp removal at identified 'hot spots', like the mouth of Sullivan's creek, Jerrabomberra Creek and wetland, Queanbeyan river and others identified through more intensive surveys. This may include use of targeted electrofishing, gill or Fyke nets, etc. Efficient removal of large numbers of carp using a range of techniques. Pilot testing of new technologies for further development. Data gathered concerning effectiveness of carp removal at hot spot habitats urrumbidgee CA olonglo Catchment Group Queanbeyan City Council Fishing clubs ACT Govt I&I NSW 61

20 Table 7 continued. Actions Priority Key outputs anticipated Anticipated outcomes Timeframe for completion Potential project partner(s) Sub-unit 3(c): Ginninderra Creek, Lake Ginninderra, Gunghalin Pond, Yerrabi Pond and other urban ponds in Belconnen 5. As part of the CEPA Plan for the UDR encourage carp catch events focussed on Lake Ginninderra or in some of Ginninderra creeks' smaller wetlands. CE Cooperative angler events held to remove adult carp and raise awareness of invasive fish. Increased community awareness of carp and support for on-ground actions onwards. ACT PC&L RiverSmart Australia Recreational fishing clubs 6. Investigate the installation of a possible carp trap at the upstream end of Lake Ginninderra to intercept spawning carp. L Installation (or transfer) of a carp trap designed to remove prespawning fish. Demonstration of carp control device for reducing spawning success. Demonstrably less adult carp entering wetland ACT PC&L 7. Support the establishment of urban pond rehabilitation demonstration sites CE. Depending on the site(s) appropriate carp control tools would be applied (installation of carp screens on inlets and outlets, for example) and these actions would be accompanied by restocking with native species and some habitat improvements (additional snags for example). See Figure 12 and the associated suggestion for systematic carp reduction activities down the Ginninderra Creek system in Section Demonstration of carp control technologies some proven and some in development. Significant change to key local habitat and native fish values ACT PC&L Recreational fishing clubs 62

21 6. onitoring and evaluation relevant to implementation of this plan Under the umbrella UDR project there has been formed a specialist group to develop and then guide the implementation of the onitoring and Evaluation Plan (&E). In the development of the &E Plan the Carp Reduction Plan has been taken into consideration so that data gathering for the UDR as a whole is an integrated and coordinated process. The following observations are provided to provide some context for how these &E aspects relating to carp have been formulated. Natural systems are complex and our understanding of them is imperfect. We can never know for certain what the outcomes of a pest management program will be. As the program progresses and monitoring data accumulates, we increase our general knowledge of the system and can better understand what the consequences of any management strategy might be. Perhaps there is concern that there will be an unintentional affect of management on a non-target species. Careful monitoring will help address this issue. onitoring is the systematic collection of information on the progress of a pest management program. It is an invaluable tool for management and provides the necessary information to evaluate the program. Evaluation is the comparison of the results from pest management against the agreed objectives of the program. There are two main forms of monitoring: Operational monitoring and performance monitoring. Operational monitoring aims to assess the efficiency of management. It is concerned with the how management was undertaken and addresses such questions as what was done, where and at what cost. By increasing the efficiency of management, more resources can be available to manage other pests, areas or the damage due to other factors such as bank instability thus increasing the cost effectiveness of management. Performance monitoring aims to assess the effectiveness of the management strategy and asks whether the strategy reduced the damage to an acceptable level. If the objective was not met, the management strategy may need to be modified or the initial pest problem reassessed to determine whether factors other than pest animals were the causes of the problem. ost funding agencies require some form of monitoring and evaluation so they can determine whether the funds have been well spent. Clearly, if there is no hard evidence that the program objectives are being achieved, it will be difficult to make a case for continued funding. Satisfying funding agencies is a valid reason for setting up a good monitoring and evaluation component to a pest management program but it is not the only, or even the most important, reason. onitoring and evaluation are also invaluable tools for the program manager. Some reasons for monitoring and evaluation include: To determine whether the damage caused by carp was reduced to the desired level by the management program. To provide feedback to those involved in the program and to maintain their engagement. To determine the efficiency of the program and how it might be made more efficient. To satisfy funding agencies and to justify continued funding and to seek additional funds. To determine whether carp actually caused the damage or that other factors were significant or more important. 63