KNOWLEDGE Rive r s

Emerging Issues in Alien Management in the Murray-Darling Basin

STATEMENT, RECOMMENDATIONS AND SUPPORTING PAPERS WORKSHOP HELD IN BRISBANE, 30-31 MAY 2006

Emerging Issues in Alien Fish Management in the Murray-Darling Basin

Statement, recommendations and supporting papers Workshop held in Brisbane, 30-31 May 2006

Dean Ansell and Peter Jackson (Editors)

Acknowledgements Sincere thanks are extended to those who participated in the workshop. A special thanks to Peter Jackson, Peter Kind, Natalie Baker, Jim Barrett, Mark Lintermans and Craig Boys for their efforts in organising and running the event. The workshop was expertly facilitated by Derek Foster. John Koehn and Mark Lintermans assisted greatly in preparation of the Statement and Recommendations for the proceedings.

June 2007 Published by Murray-Darling Basin Commission Postal Address gPO Box 409, Canberra ACT 2601 Office location level 5, 15 Moore Street, Canberra City, Australian Capital Territory Telephone (02) 6279 0100 international + 61 2 6279 0100 Facsimile (02) 6248 8053 international + 61 2 6248 8053 E-Mail [email protected] Internet http://www.mdbc.gov.au

For further information contact the Murray-Darling Basin Commission office on (02) 6279 0100

This report may be cited as: Ansell, D. and Jackson, P. (Eds). 2007. Emerging Issues in Alien Fish Management in the Murray-Darling Basin: Statement, recommendations and supporting papers. Proceedings of a workshop held in Brisbane QLD, 30-31 May 2006. Murray-Darling Basin Commission, Canberra.

MDBC Publication No: 16/07

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ISBN: 1 921257 26 1 © Copyright Murray-Darling Basin Commission 2007 This work is copyright. 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 Emerging( Issues in Alien Fish Management in the Murray-Darling Basin: Statement, recommendations and supporting papers) is acknowledged. Such reproduction includes fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act 1968. 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 improvement of the Basin’s natural resources. Printed on Impress Satin. FEATURES * ECF – elemental chlorine free * Environmentally sound - produced from managed plantations * Australian made

2 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Contents

Foreword 5

Statement and Recommendations 7

Alien in the context of the Native Fish Strategy 16 Jim Barrett

Overview of the ecology and impact of three alien 22 fish species:R edfin perch,M ozambique mouthbrooder (Tilapia) and Oriental weatherloach Mark Lintermans, Tarmo Raadik, David Morgan and Peter Jackson

Management of pest fish 33 Mike Braysher

Summary of existing alien fish management 40 mechanisms in Murray-Darling Basin jurisdictions Jason Higham

Managing pest fish in theM urray-Darling Basin: 54 lessons learnt from previous invaders John Koehn

Risk assessment modelling to identify potential fish invaders 60 Mary Bomford

Community understanding and attitudes to alien fish 69 Adrian Wells

List of participants 73

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 4 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Foreword Of the 13 objectives of the Native Fish Strategy The Workshop examined in detail some of the (NFS), one relates directly to alien species, more pertinent issues relating to alien fish in namely to ‘control and manage alien fish species’. the Basin, including control and management; Another two objectives are relevant in that the prevention and preparedness; policy, reporting improved management of alien fish will assist and decision making; and extension and to protect native fish from threats of disease communication. The need to develop a ‘toolbox’ and parasites, and protect native fish from the of up-to-date management and control adverse effects of translocation and stocking. In techniques was identified by participants.T he addition, ‘controlling alien fish species’ is one of workshop also recommended the development the six driving actions of the NFS. of a Basin-wide alien fish plan and theM DBC The NFS aims to ensure that the Basin sustains has consequently provided funding for this viable fish populations and communities initiative, to commence in 2007/08. throughout its rivers. The 50-year goal of the This Workshop is another in a series that NFS is to rehabilitate all native fish species in have been conducted over the last few the Basin back to 60 percent or more of their years to address specific issues under the estimated pre-European settlement levels. banner of the NFS. Previous workshops have Importantly, alien fish should not be regarded addressed the need for fishways, thermal as more important than other threatening pollution, translocation and stocking, processes. Without addressing other threats such downstream migration, habitat rehabilitation as habitat degradation, lack of environmental and management, the conservation and flows, barriers to fish passage and various water management of Murray cod, and fish in wetlands. quality issues, the goal of the NFS is unlikely to be achieved. This Workshop proceedings is a valuable contribution to the discussion of alien species in the Basin, particularly as it has enunciated an extensive set of recommendations on the way forward, using the objectives of the NFS as a framework. It also progresses discussion on Wendy Craik the management of three particular species. Chief Executive Two of these species, Redfin perch and Oriental weatherloach, are already present in the Basin but have until now received little attention, whilst the third, Tilapia, is dangerously close to the Basin’s northern boundaries.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 5 6 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Emerging Issues in Alien Fish Management in the Murray-Darling Basin

Workshop 30-31 May 2006

priority action in the development of the Basin- Statements and wide alien fish plan. Recommendations • It was noted that the wealth of existing international literature on the management of 1. Introduction alien fish species should be acknowledged and We, the participants of the workshop on Emerging utilised in developing management options in Issues in Alien Fish Management the Basin. in the Murray-Darling Basin, held in Brisbane • The workshop participants agreed to a basic on 30 -31 May 2006, and representing a range framework that contains the components of stakeholders, professionals and interests, considered central to the management of alien request that the Commonwealth and State species and is flexible enough to Governments and other agencies, community allow interpretation and adoption at a groups and those with an interest in the range of scales. management of alien fish species consider the • Workshop participants agreed that it will following statements and recommendations be critical to invest in a communication and arising from consideration of expert papers education program about the detrimental and discussions. impacts of alien species and the consequences Alien species are here defined as species of moving them to new catchments. Coupled originating overseas and now established in with this should be an increasing investment Australia (Harris, 1995). This definition excludes in social research. This should focus on translocated native species and these were not understanding the values, knowledge levels specifically considered at the workshop.H owever and behavioural drivers in communities. workshop participants recognised that many of the recommendations documented here are 3. Reasons for concern equally applicable to these species. 3.1 What is the problem? 2. Summary Conclusions • Much emphasis has been placed on the • It was the firm view of the workshop impacts of Carp in the Murray-Darling Basin participants that there is an urgent need for with little consideration being given to the alien species management in the Basin to be impact of other species, particularly those that developed and implemented under a Basin- are either not yet widespread (e.g. Oriental wide alien fish plan.T his should be seen as a weatherloach) or are not yet present but have component of, and be driven by the principles the potential to invade the Basin (e.g. Tilapia), of the Native Fish Strategy. It should have or those with economic or social values (e.g. specific objectives, milestones and targets. trout, Redfin perch and ornamental fish) in • It was the firm view of the workshop southern states. participants that immediate action to reduce • Whilst definitive data are lacking on the the risk of alien species already in the Basin potential impact of some of these species on spreading further or of new alien species (such the receiving ecosystems, their invasive nature as Tilapia) entering the Basin constitutes a suggests that significant impacts are likely.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 7 • Evidence suggests that there is a limited the Basin and is properly integrated with other capacity to minimise the risk of alien species management actions. spreading through the Basin, preventing new • Protect native fish populations and habitats by species entering the Basin or detecting new minimising the risks of: invasions before they become established. Neither is there evidence that techniques are - Already established alien species spreading available to control new outbreaks of these further in the Basin. species where eradication of new infestations - the introduction of new species to the is not possible. Basin from those established outside its catchment. 3.2 What will happen if the problem - new species establishing in the Basin is not addressed? that currently do not have self-sustaining Based on the collective experience of the populations elsewhere in the country. workshop participants (see Appendix page 73), • Establish techniques to enable, where the workshop has concluded that the following appropriate, alien species to be controlled will result if this problem is not addressed: where local eradication is not possible. • Currently restricted species such as Oriental • Underpin management decisions with science. weatherloach will increase their range within the Basin. 4.2 Benefits • Given the close proximity of existing Tilapia • Reduced risk of spread of alien species populations in south-eastern Queensland, it is throughout the Basin. only a matter of time before infestations occur • Collective knowledge across jurisdictions and in the Northern Murray-Darling Basin. co-ordinated approach leading to more effective • The threat of additional alien species entering management. the Basin via the ornamental fish trade • Better targeted research leading to better will continue. management outcomes. • Lack of effective removal techniques • Improved river health and aquatic biodiversity. will hamper the local eradication of new • Enhanced rehabilitation of native fish infestations even if they are detected early. populations. • Lack of effective control techniques will lead to an inability to control populations of 4.3 Beneficiaries these species where eradication has failed. • Riverine ecosystems. • The further spread of existing and newly • Native fish populations. introduced alien species will significantly • Fishers, tourism agencies, scientific impact on native fish populations and habitats community, future generations etc. and will help to confound current interventions in the Basin aimed at rehabilitating native • General community through mitigated alien fish fish populations. impacts and reduced control costs in the future by acting now. • Alien species will impact on the value of recreational and commercial . 4.4 Opportunities • Alien species will continue to impact on • There are existing initiatives that can be used Aboriginal communities of the Basin. as vehicles to achieve a Basin-wide approach, • Lack of action now will lead to the need for these include: highly expensive control actions in the future - the Murray-Darling Basin Commission (ie. prevention is better than cure). including the Native Fish Strategy; 4. Goals, benefits and opportunities - the National Ornamental Fish Policy Implementation Group; 4.1 Goals - the Invasive Cooperative Research • Under the auspices of a Basin-wide alien Centre (IA CRC); and fish plan, establish a framework for the - natural Heritage Trust funding. management of alien fish species that leads to a consistent and coordinated approach across

8 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 • An opportunity exists for the IA CRC to broaden • Inter-jurisdictional variability in legislation, its focus beyond Carp and Tilapia to include policy and response processes forms a other priority alien species. significant barrier to consistent, cooperative and effective Basin-wide management. • The Vertebrate Pest Committee (VPC) now has aquatic vertebrate pests as part of its brief. • Limited resources and competing natural resource management priorities may hinder • Use of Natural Resource Management capacity to manage alien fish species. regional contact officers may be possible to support communication of issues about alien • The issue of conflicting policies and species. management responses between fisheries and conservation agencies within some • Progress is being made in establishing jurisdictions may inhibit progress. protocols for national rotenone use permits and registration. • There is an undefined process for cost-sharing arrangements to deal with invasions of • Opportunities exist for International national significance. collaboration with New Zealand and the United States of America in both science and • Social marketing skills are not being management. adequately used in alien fish management. • Communities throughout Australia are 5. Specific Recommendations becoming more informed about pest species and recognise the associated problems. 5.1 Introduction • The recent nomination to list the spread of The workshop recognised that while there alien fish as a KeyT hreatening Processes are some significant knowledge gaps, there under the Environment Protection and is a range of very tangible and immediate Biodiversity Conservation Act 1999 (EPBC Act) actions than can and should be taken to begin could be used to help facilitate coordinated addressing the problem. A framework (Figure action across the Basin. 1) that emerged from the workshop discussions • An opportunity exists to improve the dialogue contains the components considered central to with the ornamental fish industry and angling the management of alien species and is flexible fraternity to create better understanding and enough to allow interpretation and adoption at to inform both parties about alien species a range of scales. The recommendations from initiatives. the workshop will be presented within this • The opportunity exists to develop a Basin- framework construct. The workshop identified a wide plan to combat alien fish, including a number of principles that should form the basis Geographic Information System (GIS) based for the implementation of all recommendations. database, allowing efficient and rapid transfer These principles are; of information and improved communication. Interdependency of framework components. It is acknowledged that to reduce the actions required 4.5 Potential limiting factors to achieve the goals of the alien species plan to • There are currently few control and discrete components is synthetic and is done management tools available to agencies. for expediency. The interdependencies that exist • The limited lifespan of the IA CRC may between these components are acknowledged threaten availability of research funding and and understood. strategic direction in the long term. Cultural diversity. The cultural diversity within • There is currently a lack of social science the Australian population is acknowledged. information on cultural practices and values This diversity demands an equally diverse array for communities within the Basin. of strategies for specific approaches in the extension effort and the application of science in • There exists a range of diverse and often the Murray-Darling Basin. conflicting views about the value of alien species. Whilst some people perceive these Science-based decision-making. It is animals as disruptive and a threat to native acknowledged that all decision making should species and systems, others value some of be based upon good science and should not these alien species because of food, economic, compromise the integrity of scientific information. cultural or recreational values.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 9 Governance. It is acknowledged that there are • Develop management mechanisms that four levels of governance that will need to be will actively pursue and continually promote considered within the implementation processes; greater consistency in alien aquatic fauna Federal, State, Regional and Local. management and funding across all levels of Systemic perceptions. Alien species should be seen governance within the Murray-Darling Basin. as part of a broader system of natural resource This consistency across jurisdictions should management initiatives. Interdependencies include species status, legislative controls, between these initiatives should be response processes, planning and education. constantly considered. • Ensure that the VPC deliberations include alien fish management. Develop a specific 5.2 Recommended priority actions agenda paper for the VPC that outlines alien The priority actions listed may be conducted fish species management requirements over both short and long time frames. Decisions including costs, benefits, responsibilities need to be made about the development of action and timeframes so adequate resources are plans and these decisions will be at all four levels provided to effectively address relevant alien of governance (see above). This acknowledges fish issues. that the importance of specific actions may vary • Support the nomination for listing of the within species, geographic locations and existing ‘introduction of fish outside their range’ as a policy demands across the Murray-Darling key threatening process under the EPBC Act Basin. Management actions for alien fish will be and State legislation. undertaken within broad pest • Initiate processes to allow alien fish management principles. management to be integrated with other alien species natural resource management 5.2.1 Alien species management initiatives. This may embrace both terrestrial Workshop participants identified the need for a and aquatic dimensions and include both plant number of overarching management actions and and targets. areas of policy development that were required • Develop criteria for determining the success of if more effective alien species management was management actions. to occur in the Basin. These priority actions are outlined below: • Define the key outcomes of alien species management within the context of broader • Develop and implement a Basin-wide alien ecosystem management. species plan. This should be seen as a component of the Native Fish Strategy (NFS) • Undertake pathway analysis (i.e. the possible and be guided by the principles of the NFS. This pathways by which an alien fish species can plan should act as a driver for a complementary invade a waterway and the associated vectors State and national based approach. The plan and risks of each component of the pathways) should also recognise and define the roles, as an independent component of alien fish responsibilities and cost-sharing arrangements management and integrate the results of stakeholders. The plan should include, but into control, prevention and engagement not be restricted to: strategies. Explore efficiencies to be gained by linking with other response programs and - rapid response components (may be organisations. addressed, in part, by the IA CRC project and the emergency response being developed by the Queensland inter-departmental pest management committee). - specify objectives, milestones and targets which should align. - strategic processes for the containment and disposal of declared noxious or unwanted species e.g. amnesty, disposal point and logistics for removal. - Consistent definition of alien species across jurisdictions and listings under consistent legislation.

10 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 5.2.2 Prevention and preparedness used to develop appropriate management. This consideration of ‘values’ acknowledges Workshop participants recognised that high the differences that exist within community priority must be given to the prevention of new perceptions of alien fish.T hese differences infestations of alien fish species in the Basin. include values of: desirable recreational Reduction in the risk of new infestations will only fisheries; negative impact on native species be achieved if appropriate response mechanisms, and communities; commercial industry; resources and expertise are in place across the spiritual, religious and cultural connections; Basin. Key actions required to achieve this are and indigenous culture. outlined below: • Ensure indigenous participation in the • Establish dedicated full time alien fish management of alien species and engagement management teams in jurisdictions throughout of indigenous communities is a priority. the Murray-Darling Basin. These teams will have a primary responsibility for rapid response • Define roles, responsibilities and actions with additional responsibility including accountabilities of stakeholders in alien fish community liaison activities as prescribed by species management. both the overarching plan and local needs. • Engage other stakeholders such as non- • Conduct a risk-based assessment for new, fisheries agencies, regional natural resource potential and existing invaders. This should management bodies, private sector and the initially cover assessments of all species known broad community in alien fish to have been imported to develop an alert list. management processes. An assessment of other potential invaders that have been successful overseas should also 5.2.4 Extension and communication be undertaken. The resultant alert list should Workshop participants recognised that most inform alien species management including new infestations of alien fish species result education programs, legislative controls and from human intervention. For example, there is enforcement activities. ample evidence that Tilapia are still being actively • Establish a contingency/emergency fund for spread to new catchments in Queensland by alien species management to ensure resources accidental or deliberate introductions by people. for preparedness and on-ground rapid response. The dangers associated with introducing alien fish species are not clearly understood by all • Further develop and adopt the ‘vulnerable sectors of the community. Priority actions to catchment’ (i.e. catchments susceptible to address these issues are outlined below: infestation by a particular alien species) approach to prioritise management. • Increase the investment in communication activities for alien fish across theM urray- • Collaborate with the National Ornamental Fish Darling Basin. This should be driven by a Policy Implementation Group, or its successors, communications strategy and should target the aquarium industry and hobby groups such raising awareness and knowledge of a range as the Australia and New Guinea of stakeholders (e.g. general public, specific Association. groups, management agencies, politicians, • Strengthen and support community-based anglers etc). detection and prevention programs. • Increase social research focusing on 5.2.3 Policy, reporting and decision making understanding values, knowledge levels and behavioural drivers in communities. The The management of alien fish species must be results of this research should act as a guide undertaken within the context of the broader to allow extension strategies to accommodate community and its values and expectations. value differences within the Basin. Management actions must engage all • Direct specific extension efforts toward stakeholders and recognise their roles and indigenous communities throughout the responsibilities. Some key recommendations are Murray-Darling Basin. outlined below: • Identify other social diversities (ethnic, • Consider the diversity of ‘values’ of alien cultural, interest, spiritual) in communities species to specific communities and the and tailor engagement and communication broader community throughout the Murray- activities to reflect this. Darling Basin and ensure that these values are

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 11 • Develop appropriate community engagement 5.2.6 Toolbox materials and processes based upon the Workshop participants recognised the full range of tools, strategies and literature importance of shared knowledge in relation to the that has emerged through previous resource management of alien fish species.T he concept of management activities and initiatives in developing a ‘toolbox’ of up-to-date management Australia and overseas (e.g. Landcare, and control techniques was widely supported. The Cooperative Research Centres etc). These following actions were recommended: materials and processes should also be informed by the results of social research. • Develop a ‘toolbox’ of management techniques for the removal and control of alien species. • Raise the public profile of alien species as a This ‘toolbox’ should be a collaborative and threatening process. cooperative effort between all jurisdictions and • Report both failures and successes of be commonly available and used across management actions. the Basin. 5.2.5 Control and management • Develop new tools for control and management of alien species and add these to Some alien species such as Carp are well the ‘toolbox’ including: established within the Basin and the workshop - Chemical (e.g. poisons); acknowledged that prevention measures will reduce the risks of new infestations but will not - Approvals (e.g. permits); always be successful. New infestations may still - Containment (e.g. exclusion screens); occur over time. It is important that jurisdictions - Biological (e.g. virus/genetic); in the Basin are in a position to undertake - species vulnerabilities (ie. ‘Achilles heel’); effective control measures if eradication is not possible. Workshop participants identified the - Planning and modelling. following priority actions related to the control of • Place a greater investment in the development established populations of alien fish species: and implementation of detection technologies. • Utilise demonstration reaches under • Maintain the database of fish distribution the Native Fish Strategy as a means of recently developed under the Native simultaneously rehabilitating fish habitat Fish Strategy. and controlling alien species in an • Develop a reference compendium for social integrated manner. research, education and extension processes. • Build capacity in alien fish management across agencies, authorities and jurisdictions. This 5.2.7 Species specific management should include activities such as multi-state and research teams, training workshops, scenario testing, experiential learning and community- A. Redfin perch based research. A.1 Management • Undertake monitoring to determine • Collate a species synopsis including biology, success and failure against stated objectives distribution, social and economic values, and targets at both the community and likely environmental impacts and present scientific levels. management arrangements. • Use adaptive experimental management • Update information on Epizootic to test specific questions and Haematopoietic Necrosis Virus (EHNV), management hypotheses. as it becomes available. • Undertake and report bioeconomic • Ensure no stocking or translocation in assessments of potential and existing any jurisdiction. management actions to help ensure • Develop management options to isolate and appropriate resources necessary for stop the species spreading further within the successful alien species management. Basin (i.e. targeted education). • Develop database and GIS capacities with • Establish a demonstration reach to include the connections to international databases and control of redfin. experts to assist alien species management.

12 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 A.2 Research behaviour in relation to exposure to these chemicals. • Investigate Redfin perch and Carp interactions to predict likey outcomes on Redfin perch • Investigate the tolerance of Oriental populations if Carp are removed. weatherloach to desiccation and the impacts of this on control options. • Investigate native species alternatives for recreational angling. • Clarify the of Oriental weatherloach in Australia. • Investigate the effects of EHNV in the wild and continue tests on other native species in • Collate information on diseases the laboratory. associated with Oriental weatherloach in their native range. • Collate information on diseases associated with Redfin perch in their native range. • Investigate the potential use of pheromones in the control of Oriental weatherloach. • Investigate the ability of Redfin perch to acclimate to water temperatures outside their • Investigate movement patterns and dispersal normal tolerance range. mechanisms associated with Oriental weatherloach. • Investigate the tolerances of Redfin perch to various piscicides and their behaviour in relate • Undertake social research with a focus on to exposure to these chemicals. recreational anglers in relation to use of baits and target species. • Investigate movement patterns and dispersal mechanisms associated with Redfin perch. • Investigate the impacts of Oriental weatherloach on native species including; • Investigate the impacts of Redfin perch on native fish species including; direct interactions direct interactions (aggression, predation, (aggression, predation, competition for food and competition for food and space) and space) and habitat damage. habitat damage. • Investigate the behaviour of Oriental • Model the likely response of Redfin perch populations to thermal pollution mitigation. weatherloach to inform control measures. • Investigate the feeding habits of • Investigate the use of sterile male Redfin perch as a control option. Oriental weatherloach. • Investigate the potential use of natural • Undertake social research with a focus on recreational anglers in response to the use of predators as a control method for Oriental baits and target species. weatherloach, particularly Eel-tailed catfish. • Investigate the ability of Oriental weatherloach to • Better define the social and economic values of Redfin perch. acclimate to water temperatures outside their normal tolerance range. B. Oriental weatherloach C. Tilapia B.1 Management C.1 Management • Collate a species synopsis including biology, distribution, social and economic values, • Undertake a targeted community education likely environmental impacts and present program with an emphasis on the risks management arrangements. associated with the spread of Tilapia into the Basin. Involve recreational fishers • Implement targeted education/extension in the program. program to minimise the risk of Oriental weatherloach spreading further in the Basin. • Finalise the rapid response process This program should recognise that the being developed in Queensland and develop species is used as live bait. into a Basin-wide response. • Involve southern states in Queensland • Develop control techniques and undertake control activities based on cost/benefit activities to build capacity in analysis for prioritisation of actions. Tilapia management. • Investigate the community attitudes to the B.2 Research species, particularly why some anglers • Investigate the tolerances of Oriental appear to support a Tilapia in north weaterloach to various piscicides and their Queensland rather than a native species

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 13 fishery. Determine methods to reverse this overseas literature. Liaison with hobbyists perceived trend. should also be undertaken. • Develop a GIS database for alien species C.2 Research that identifies ‘at risk’ catchments (high • Investigate the ability of Tilapia to acclimate to value, high probability of infestation, etc) and temperatures outside their normal tolerance incorporates environmental classification range particularly in relation to lower tools (systematic conservation planning tools). temperatures that would be experienced in the • Investigate dispersion pathways and define Murray- Darling Basin. vectors (quantify risk) for high risk alien • Collate information on diseases associated species. Investigate the use of molecular with Tilapia in their native range. methods to determine multiple introductions. • Clarify the taxonomy of Tilapia in Queensland • Quantify impacts of alien species with priority including the occurrence of hybrids. being given to established species. Research • Investigate the tolerances of Tilapia to various should include before and after invasion piscicides and their behaviour in relation to studies; impacts on individual native species; exposure to these chemicals. impacts on ecosystems; thresholds for impacts and density dependency of impacts. • Investigate methods for early detection of Tilapia in waterways and wetlands. • Investigate techniques to assist with early detection of alien species. • Investigate methods of attracting Tilapia (including acoustic methods) to assist in • Establish adaptive experimental management control measures. sites to test hypotheses. These should include goals, strategies and the evaluation • Investigate movement patterns and dispersal of alien species management verses other mechanisms associated with Tilapia. rehabilitation practices. • Investigate the impacts of Tilapia on • Undertake risk assessments of alien species native species including direct interactions management practices and link results to (aggression, predation, competition for food modelling pathways. and space) and habitat damage. • Undertake modelling of various management • Undertake social research with a focus on scenarios, population dynamics, feasibility/ recreational anglers in relation to use of baits likely results and extent of spread. and target species. • Undertake bioeconomic investigations of alien 5.2.8 General Research Recommendations species management practices including cost/benefit analysis and impacts of alien • Investigate technical control options to evaluate the best techniques for particular species on ecosystem services. alien species and link these to modelling • Investigate the potential ecological of potential management strategies. consequences of successful removal of Investigations should include policy research, different alien species including the likelihood biological control (genetics, disease), of recovery, thresholds for effects and density chemical control (pheromones, piscicides, dependency. Information on other vertebrate disruptors) and mechanical controls (screens, pests should be examined. removal, traps). • Develop decision frameworks for alien • Undertake social research to investigate species management and ensure that these the drivers of community attitudes and are integrated with other vertebrate pest how these attitudes can be changed where species management. necessary. This research should encompass • Undertake a critical assessment of past all stakeholders including the community, alien species management techniques and governments and institutions, legislators, initiatives, both national and international. decision-makers, and politicians. • Target multi-disciplinary knowledge exchange. • Investigate the biology of alien species in Australia to identify potential “Achilles heels”; interaction impacts; environmental tolerances. Priority should be given to synthesis of existing data particularly through the examination of

14 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 References Harris, J.H. (1995). The use of fish in ecological assessments. Australian Journal of Ecology. 20 (1), 65-80.

Figure 1: Alien Species Management Framework

Alien species management

Prevention and preparedness Control and management

Policy, reporting and decision-making Toolbox

Research and knowledge Extension and communication

Measurable outcomes with timeframes

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 15 Alien species in the context of the Native Fish Strategy

Jim Barrett Murray-Darling Basin Commission, GPO Box 409, Canberra act 2601

Abstract Australia’s freshwater ecosystems. The NFS lists them as one of eight key threats to native fish in The Native Fish Strategy for the Murray-Darling the Basin, where 12 alien species are present. Basin 2003–2013 lists alien species as one of Hence, of the 13 objectives of the NFS, one eight major threats to the decimated native relates directly to alien species, namely to fish populations of theM urray-Darling Basin. ‘Control and manage alien fish species’. Another To achieve its 50-year goal of restoring native two objectives are relevant in that the improved fish populations to at least 60% of former pre- management of alien fish will assist to: European levels, the Strategy recognises that all • ‘Protect native fish from threats of disease and threats must be addressed, and in a sustained parasites’; and and integrated manner. In addressing the alien fish problem, theS trategy’s immediate tasks • ‘Protect native fish from the adverse effects of are to: limit the further spread of alien species; translocation and stocking’. prevent the establishment of more alien species; In addition, ‘Controlling alien fish species’ is one incorporate alien species management into of the six driving actions of the NFS. the broader framework of river rehabilitation; The contribution of alien species management employ demonstration reaches as models; apply to the NFS is important to its overall goal of an integrated package of control techniques to rehabilitating native fish to 60% of pre-European problem sites and monitor the results, with the population levels in 50 years (MDBC 2004). focus on reducing the damage caused by alien Nevertheless, it should not be regarded as species rather than on their density; support more important than the other key threatening the development of new control technologies; processes. A scientific panel—established to undertake risk assessments for alien fish species develop a conceptual model, or models, to currently in captivity; and educate and engage the inform NFS deliberations and future investment community in alien fish problems decisions—reported that without addressing and their management. other threats such as habitat degradation, lack of environmental flows, barriers to fish passage and various water quality issues, the 60% goal is unlikely to be achieved. Background The NFS advocates an integrated approach In May 2003, the MDB Ministerial Council to alien species management, involving the approved a ten-year Native Fish Strategy (NFS) simultaneous application of a package of control for the Murray-Darling Basin 2003-2013 (Murray- techniques. Currently, singular techniques for Darling Basin Commission 2004). The 2003–2013 controlling carp include capture and removal Strategy is the first stage of a 50-year plan to (e.g. , carp separation cages), rehabilitate native fish populations throughout chemicals (e.g. rotenone—with limitations on its the Basin by addressing key threats and use), environmental manipulation (e.g. lowering providing direction for investment in on-ground wetland levels after a breeding event), exclusion management activities and research. devices (e.g. screens) and biological control (e.g. Alien fish are recognized as a significant threat to genetic modification and viral control agents).

16 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 In terms of broad-scale river rehabilitation, alien To help manage this issue, a package of species management would be expected to be documents has been prepared and released. a component of most large projects, including These are: demonstration reaches. Demonstration reaches • The National Management Strategy for Carp are large-scale river reaches in which multiple Control (NMSCC), produced by the Carp Control fish habitat management interventions are Coordinating Group (CCCG 2000a); applied in order to increase awareness and • Managing the Impacts of Carp, produced by the support for fish conservation (Barrett & Ansell Bureau of Rural Sciences under the National 2004). The aim of the demonstration reach is Feral Animal Control Program not to restore fish habitat to original or pristine (Koehn et al. 2000); condition—a common and often unrealistic expectation of stream rehabilitation programs. • Ranking Areas for Action: A Guide for Carp Instead, the demonstration reach concept Management Groups (Braysher & Barrett recognises the need to address all threats 2000); and to native fish, not just those most obvious or • Future Directions for Research into Carp, convenient, whilst simultaneously showcasing the produced by the CCCG (CCCG 2000b). benefits of river rehabilitation for native fish to The Bureau of Rural Sciences publication, the community. Managing the Impacts of Carp, outlines a strategic Overall river rehabilitation also extends to the approach to carp management and provides a declaration of protected areas for native fish such detailed discussion of carp damage and control as habitat management areas (as defined in the techniques. The National Management Strategy NFS) and “river parks” (Phillips and Butcher For Carp Control provides the national framework 2005). There may be a need for an aim to exclude for progressing carp management. The third alien species in these protected areas rather than document, Ranking Areas for Action: A Guide managing their damage. for Carp Management Groups (guidelines) is a practical step-by-step tool to assist local groups plan and implement the NMS at the catchment/ Actions required under the sub-catchment level. The package of documents Native Fish Strategy is unique. Together they take a major resource management issue from the policy development The NFS sets out several prescriptions that stage through to practical ways to address it at guide effort and investment in the control of the local level. alien species. In terms of management, the Strategy dictates that the Murray-Darling Basin (ii) Resolve inconsistencies in legislation Commission (MDBC): and policy (i) Implement the National Management As with many regulatory issues, each State and Territory has fish and fisheries management Strategy for Carp Control, including regional legislation (see Higham et al. carp management plans pg 40 this publication) that deals with the raft of It is now known that controlling the damage issues relating to alien freshwater fish species, caused by carp is a complex management issue. including size and bag limits, importation, Carp impact is closely linked to many other stocking and translocation. The provisions for factors that have degraded Australia’s waterways dealing with these issues vary significantly and hence the quality of native fish habitat (CCCG between jurisdictions. 2000a). These factors include salinity, high nutrient loads leading to algal blooms, excessive (iii) Develop reporting and rapid response water extraction and construction of dams and systems for new alien species weirs that are a barrier to the movement of many It is now common practice to have a contingency native fish (Braysher and Barrett 2000). plan (or ‘rapid response system’) in place to deal quickly and effectively with the outbreak of a pest or disease. When unconfirmed reports of Tilapia in the northern limits of the Murray- Darling Basin were received in 2000, the MDBC organised a facilitated workshop in Toowoomba

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 17 to discuss a rapid response system for new alien to consider dispersal, especially of young-of- species. Consequently, a rapid response system is year, when designing fishways (i.e. to include now being developed for invasive freshwater fish carp separation cages) and the control of critical in Australia. The project will review national and access points for carp (both adults and juveniles) international practice in response to new outbreaks to and from the Barmah-Millewa floodplain. of alien fish and examine the success or otherwise With funding from the MDBC, the Invasive Animal of attempts to eradicate alien fish in Australia. Cooperative Research Centre is attempting to Other outcomes of the project will include: determine the location of hot spots for carp • documentation of response plans for new recruitment. It appears that carp spawning is alien fish incursions for all AustralianS tates/ highly habitat specific and most carp breeding Territories; occurs in a limited number of areas. Potentially, • review of potential control and or containment as few as five areas inN ew South Wales account methods; for the vast bulk of carp recruitment (D. Gilligan pers. comm 2006). • adoption of a consistent approach to new alien fish incursions in Australia; and (vi) Identifying areas free of alien species • identification of opportunities to field test the One of the key goals of the National Management response capability. Strategy for Carp Control is to prevent the further (iv) Encourage an integrated pest spread of carp. This includes the need to identify environmentally valuable areas where there is a management approach risk that carp will be introduced or re-introduced, The notion of integrated pest management (IPM) and to promote community understanding and involves the simultaneous application of a range of support for controls on the movement of live control techniques, applied strategically and as an carp. Keeping areas free of alien species is cost- integrated package in order to achieve a significant effective in terms of conservation management, and measurable reduction in the damage caused but requires public support and vigilance. by a pest species. IPM is about: • a focus on reduction of the damage done to the (vii) Identifying potential new alien species ecosystem rather than simply on the density or and their likely impacts numbers of the pest species causing While the Environment Protection and Biodiversity that damage; Conservation Act 1999 includes a list of about • using a combination of techniques at the same 500 species of alien freshwater fish that time (more or less); are permitted imports to Australia (primarily for • monitoring the response of the system to the the aquarium trade), changes in legislation over use of these techniques; time, inconsistencies in legislation and outright smuggling mean the exact number of species • acknowledging that the relative importance actually in Australia is not known (but suspected or weight of each technique varies to be in the thousands) (see other papers in this in each situation; publication). Because many of these species have • adapting and refining the targets over time. not been assessed through current import risk In terms of research and investigation, the assessment process, the potential impact should Strategy recommends concentrating effort in the they escape or be released is not known. An following areas: agreed national noxious species list has recently been adopted, and a priority list developed of (v) Identifying key regions, such as species that need further assessment (Natural recruitment areas, and dispersal patterns Resources Ministerial Council 2006). This will be In 2002 the Arthur Rylah Institute (ARI) identified accompanied by public education and awareness that the Barmah-Millewa floodplain is a point campaigns to address issues related to species source for carp recruitment (Stuart & Jones 2002). that present a potential significant risk that are ARI found that the majority of adult carp occupied already in the country. one or more ‘home areas’ on the Murray River and the floodplain, and that river flow was the main cue for movement between these. Management implications from these findings include the need

18 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 (viii) Addressing key knowledge gaps carp in Australian waterways. The Task Force There are major gaps in knowledge on carp and had representation from Local Government, other alien fish. Areas of research needed include researchers, agencies, community, anglers, biology, distribution and damage to native fish commercial fishers, and catchment and the environment, effective control strategies, management. The Task Force supported a commercial use and disease. For carp, these range of education, community engagement, gaps are documented in the MDBC publication research, business, and wetland initiatives. In Future Directions for Research into Carp 2002, the Task Force changed its name (CCCG 2000b). to the National Carp & Pest Fish Task Force to reflect increasing concern over the 11 (ix) Investigating the application of other alien fish threatening the Murray-Darling biotechnology Basin. The Task Force developed an action plan to ensure community participation and has since The MDBC has already invested over $4M been implementing the plan, much of it through in the ‘daughterless carp’ concept, and has participation in the Native Fish Strategy and the committed another $5M over the next few years. work of the Pest Animals & Invasive Animals Daughterless carp technology can be described Cooperative Research Centres. as ‘a genetic construct, using species-specific genes, that is inheritable and biases offspring sex (xii) Carp-a-thons ratios towards males’. In theory, to instil into wild In the Logan-Albert system just outside the carp a heritable bias towards males will inevitably Basin in south-east Queensland, a community distort sex ratios, leading to reproductive group, ‘Carp Busters’, has been mobilising failure and population crashes. Nonetheless, the local community to remove carp through daughterless carp technology should not be seen organised recreational angling events. Whilst as a ‘silver bullet’, rather as part of a package of it is doubtful whether such events have any integrated control. benefit in terms of reduction in carp numbers, Finally, in terms of community engagement, the especially considering that a female carp can Strategy emphasises: produce up to 7 million eggs (Koehn et al. 2000), these events provide a useful method for (x) The need to encourage actions developing community awareness of alien fish undertaken by communities on controlling and encouraging them to become involved in alien species their management. Community groups and catchment management organisations are becoming increasingly active (xiii) The role of commercial fishing in alien species control, particularly in wetlands. Commercial carp fishing occurs inV ictoria, Nevertheless, a greater emphasis needs to South Australia and (irregularly) in New South be placed on education about some alien Wales (such as at Moira Lake in the Barmah- species such as Eastern and Oriental Millewa Forest). Freshwater commercial fishing weatherloach, which are often mistakenly is prohibited in the MDB in Queensland. While regarded as benign (Driver et al. 2005). commercial fishing is not an effective means of control in itself, it can be a valuable component Species such as carp not only breed in wetlands, of an integrated pest management program. For but also quickly out-compete native fish (Koehn example, at times it may be useful as a short- et al. 2000). The fact that they are the first to term management tool while techniques for enter and the last to leave wetlands following wider control are being developed. connection to the main channel (Driver et al. 2005) offers potential for effective community management solutions.

(xi) Existing mechanisms such as the National Carp and Pest Fish Task Force The National Carp Task Force was established in 1976 by the Murray Darling Association to provide a strong focus for practical community and Local Government action on managing

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 19 In summary, the way forward for alien fish Concluding remarks management in the MDB involves: The NFS recognises that the response of native • limiting the further spread of alien species, fish populations to various kinds of rehabilitation, whether that spread is by accidental release, including alien species management, is discarding of unwanted fish, or deliberate cumulative and will take time. It is clear that introduction of such fish to new waters as a addressing just a few of the threatening processes source of table fish, bait and/or recreation; will produce only modest results. In order to • preventing the introduction of new alien achieve the Strategy’s goal of 60% reinstatement species, which necessitates tighter import of native fish populations in 50 years M( DBC 2004), restrictions, rapid reporting and response, and the major contributing threats need to be dealt community education; with concurrently, in an integrated way. • incorporating alien species management into The concept of demonstration reaches is gaining the broader framework of river rehabilitation momentum as a pragmatic mechanism for as a normal management intervention in effecting river rehabilitation across significant rehabilitation programs, including those for stretches of degraded but restorable river demonstration reaches; systems. Alien species control is one of the tangible actions that can be undertaken in an • applying an integrated package of integrated way in a demonstration reach. management techniques to a number of problem areas or hotspots, and measuring the In terms of carp, it is important to implement the results, with the focus on reducing the damage National Management Strategy for Carp Control caused by alien species rather than on and Ranking Areas for Action: A Guide for Carp their density; Management Groups. Although there are no silver bullets, encouraging new breakthroughs include • cautiously supporting the development of new the continued refinement of carp separation control technologies on the basis of: (a) their cages, the development of a rapid response potential to usefully augment the current system for new outbreaks and the identification of range of techniques; (b) their likely social, recruitment ‘hotspots’. ‘Blue sky‘ research such as political, economic and logistical acceptability; daughterless carp technology and Koi herpes virus (c) their progress at ‘stop-go’ points in their may eventually significantly augment the armoury developmental phase; (d) the availability of of techniques available to effectively manage funding; and (e) continued favourable review this species. against (a) and (b); It is crucial to involve the community in alien • assessing the risk of establishment in the wild species management. Cooperation between of alien fish species currently in captivity in management agencies, community groups, and Australia, or likely to be proposed for import, sectors such as recreational fishing, commercial and their potential environmental, economic fishing and tourism, is essential and partnerships and social impacts; need to be fostered through locally developed and • educating the public on alien species owned management plans. Improved community and their impacts and engaging them in awareness and understanding of alien species on-ground management. issues can be achieved by targeted publicity on: the biology and damage caused by such species; national, regional and local strategies and control References programs; and the impacts of alien species on Barrett, J. 2001. Australia’s National Management community assets and resources, such as water and Strategy for Carp Control. In: Managing Invasive fisheries, in the context of other factors that impact Freshwater Fish in New Zealand. Proceedings of a on them. For their part, communities (through workshop hosted by Department of Conservation, 10–12 May 2001, Hamilton. Department of groups such as the National Carp and Pest Fish Conservation, Hamilton, New Zealand. Task Force) can encourage local stewardship of the Barrett, J. and Ansell, D. 2005. Demonstration aquatic environment and coordinate local group reaches for native fish: moving from theory to development and action. They can also improve the practice. In I. D. Rutherford, I. Wiszniewski, M. J. quality and objectivity of education used in raising Askey-Doran & R. Glazik (Eds.) Proceedings of the 4th community awareness of alien species and what can Australian Stream Management Conference: linking be done to manage them. rivers to landscapes. (pp. 59-67).

20 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Braysher, M. and Barrett, J. 2000. Ranking Areas for Action: A Guide for Carp Management Groups. Murray- Darling Basin Commission, Canberra. Carp Control Coordinating Group 2000a. National management strategy for carp control 2000-2005. Murray-Darling Basin Commission, Canberra. Carp Control Coordinating Group 2000b. Future directions for research into carp. Murray-Darling Basin Commission, Canberra. Driver, P., Stuart, I., Closs, G., Shirley, M. and Harris, J. 2005. Carp (Cyprinus carpio L.) impacts and recruitment in Australian wetlands: strategies for management. In: Native Fish and Wetlands in the Murray-Darling Basin. Workshop held in Canberra, 7–8 June 2005. Murray-Darling Basin Commission, Canberra. Koehn, J., Brumley, A. and Gehrke, P. 2000. Managing the Impacts of Carp. Bureau of Rural Sciences (Department of Agriculture, Fisheries and Forestry – Australia), Canberra. Murray-Darling Basin Commission. 2004. The Native Fish Strategy for the Murray-Darling Basin 2003–2013. Murray-Darling Basin Commission, Canberra. Natural Resources Ministerial Council. 2006. A strategic approach to the management of ornamental fish in Australia. Department of Agriculture, Fisheries and Forestry Canberra. Phillips, B. and Butcher, R. 2005. River Parks: Building a System of ‘Habitat Management Areas’ Across the Murray-Darling Basin: An International and National Review of Freshwater ‘Protected Areas’ for Conserving Aquatic Biodiversity and River Health. Murray-Darling Basin Commission, Canberra. Stuart, I. and Jones, M. 2002. Ecology and Management of Common Carp in the Barmah-Millewa Forest. Final report of the Point Source Management of Carp Project to Agriculture Fisheries and Forestry Australia. Arthur Rylah Institute, Victoria.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 21 Overview of the ecology and impact of three alien fish species: Redfin perch, Mozambique mouthbrooder (Tilapia) and Oriental weatherloach.

Mark Lintermans1, Tarmo Raadik2, David Morgan3 and Peter Jackson4 1Environment & Recreation (Research & Monitoring), Department of Territory & Municipal Services, PO Box 144, Lyneham, ACT, 2602. [email protected] 2Freshwater Ecology, Arthur Rylah Institute for Environmental Research, DSE, 123 Brown Street, Heidelberg VIC 3084. [email protected] 3Centre for Fish & Fisheries Research, Murdoch University, South St Murdoch, Western Australia, 6150. [email protected] 4Fisheries and Development, Department of Primary Industries and Fisheries, GPO Box 46, Brisbane, Qld 4001. [email protected] 5Current address: Murray-Darling Basin Commission, GPO Box 409, Canberra ACT 2601.

Abstract Introduction This paper addresses various ecological impacts and knowledge gaps surrounding two introduced Why Redfin perch, Mozambique fish species that are currently entrenched within mouthbrooder (Tilapia) and Oriental the Murray-Darling Basin, namely Redfin perch weatherloach? (Perca fluviatilis) and Oriental weatherloach Alien species and their associated impacts are (Misgurnus anguillicaudatus), and a third species, considered to be a key threat to native fish not the Mozambique moothbrooder or Tilapia only in the Murray-Darling Basin (MDB) (MDBC (Oreochromis mossambicus), that is likely to 2004), but also nationally (e.g. Arthington & invade the system in the near future. The main McKenzie 1997, Koehn & Mackenzie 2004, vectors of dispersion throughout the catchment Lintermans 2004, Morgan et al. 2004) and are identified as being either through illegal internationally (Fuller et al. 1999; Moyle & Light stocking, as escapees from ornamental or farm 1996; Rahel 2002), and the management of alien ponds, as bait bucket introductions or through species may be one of the biggest challenges water diversion. For sound management of each that conservation biologists will face in the of the species, adequate resources need to be coming decades (Allendorf & Lundquist 2003). directed towards filling voids in our knowledge The Australian freshwater fish fauna contains a of the species within the Murray-Darling Basin. high proportion of alien species (~34 out of ~240 Resources should be directed at acquiring an fish species), with 12 of 53 (23%) freshwater understanding of habitat and environmental fish species in theM DB considered alien (11 requirements, species ranges, general biology exotic, 2 translocated) (Lintermans in press). and ecology, interactions with native species, Consideration of the issues surrounding all of disease risk and social reasons behind the alien species in the MDB was not deemed deliberate releases. feasible in a 2 day workshop, so three species, Redfin perch(Perca fluviatilis), Mozambique mouthbrooder or Tilapia (Oreochromis mossambicus) and Oriental weatherloach (Misgurnus anguillicaudatus), were selected as focal taxa. Consideration of the impacts on native biota and the specific management issues of

22 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006

Figure 1. Redfin perch(Perca fluviatilis). Photograph: G. Schmida

these three species would provide some context to the wider issues of alien fish management Overview of the in the MDB. Redfin perch is a moderate sized, Ecology of the species long-established, widely distributed species in the MDB, with a range of ecological issues Redfin perch (Perca fluviatilis) and public values/perceptions (ecological impact vs. value as recreational species). The Distribution Mozambique mouthbrooder is also a moderate Redfin perch (Figure 1) attain a maximum size sized species whose range is expanding rapidly of 600 mm total length (TL) (commonly 300 on the northern edge of the MDB and is likely mm, 1-2 kg) (Cadwallader & Backhouse 1983). to become established in the future. As an The species was introduced to Australia from invasive species it is known to cause ecological England between 1858 and 1862 (to Tasmania) impacts but is also valued as a recreational and and 1861 (Victoria) (Clements 1988; Morgan et commercial species. Oriental weatherloach on al. 2005; Weatherley 1977). The species is now the other hand is a small, recent invader of the widely distributed in the lower to mid reaches of MDB and has its origins in the aquarium-trade the MDB (South Australia, Victoria, New South (the source of all recent invasions) (Lintermans Wales, Australian Capital Territory) and is also 2004). While its range is expanding within the present in southern Western Australia (Morgan MDB, its precise distribution is poorly known et al. 2002, 2004) and Tasmania (McDowall 1996). due to its cryptic behaviour and its largely It is not present in Queensland or northwestern unknown ecological impacts are hindered by a NSW and its distribution is partly limited by high lack of research. water temperatures (an upper thermal limit of 30–31ºC) (Weatherley 1963, 1977). Despite its known impacts on native fish and (see below), Redfin perch is a valued target for

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 23 recreational fishers, particularly inV ictoria, and is Either Redfin perch, Carp(Cyprinus carpio) or still being actively spread (illegally) in the MDB by Goldfish(Carassius auratus) is suspected of anglers (Lintermans unpubl. Data). introducing the parasitic copepod Lernaea to Australia (Langdon 1989a), and Redfin perch Ecology is the main host for Epizootic Haematopoietic Redfin perch is a schooling species, particularly Necrosis Virus (EHNV), which is unique to as juveniles, and occurs in a wide variety of Australia. First isolated in 1985 from Redfin habitats, but prefer still or slow–flowing waters, perch, this virus is characterised by sudden usually with abundant aquatic vegetation. high mortalities of fish (Langdon et al. 1986, Langdon & Humphrey 1987). Experimental It is a voracious carnivore, with the diet of work has demonstrated that Macquarie small fish (<100 mmTL ) consisting mainly perch (Macquaria australasica), Silver perch of zooplankton & dipteran pupae, with larger (Bidyanus bidyanus), and Mountain galaxias aquatic invertebrates (odonatans, decapod are among several native species extremely crustaceans) becoming more dominant in mid- susceptible to the disease, as well as the alien size fish (100-200 mmTL ); with Redfin perch species Rainbow trout (Oncorhynchus mykiss) > 200 mm TL consuming predominantly fish, and Eastern gambusia (Gambusia holbrooki) crayfish and odonatan larvae (Morgan et al. 2002). (Langdon 1989b). Furthermore, Murray cod are Spawning occurs in late winter‑early spring (July capable of carrying the disease and Macquarie to September), when water temps reach 11–12°C. perch (Macquaria australisica) exposed to Fecundity is high (up to 45 000 eggs/kg of body water that had held infected Redfin perch weight), with up to 200 000 eggs/female recorded demonstrated 100 % mortality within 6-11 days (see Morgan et al. 2005). (Langdon 1989b). The virus is very resistant Impacts to desiccation, with dried samples retaining their infectivity after 113 days, but not at 200 Redfin perch are known piscivores but also days (Langdon 1989b). The virus has now been prey heavily on freshwater crayfishes. Within recorded in South Australia, New South Wales, Australia they have been documented as the Australian Capital Territory and Victoria predating on a large number of native fishes (Whittington et al. 1996), and once EHNV is in a including Carp gudgeons (Hypseleotris spp.), waterbody, it is considered impossible Murray cod (Maccullochella peelii peelii), Golden to eradicate. perch (Macquaria ambigua), Western pygmy perch (Edelia vittata), Southern pygmy perch Mozambique mouthbrooder or Tilapia (Nannoperca australis), Yarra pygmy perch (N. (Oreochromis mossambicus) obscura), Ewens pygmy perch (N. variegata), Nightfish(Bostockia porosa), Mountain galaxias Distribution (Galaxias olidus), Flatheaded galaxias (G. rostratus),Obscure galaxias (Galaxias sp.1), Two species in Australia are commonly Common galaxias (Galaxias maculatus), Eastern referred to as Tilapia: the Black mangrove little galaxias (Galaxiella pusilla), River blackfish (Tilapia mariae), native to the coastal (Gadopsis marmoratus), Flatheaded gudgeon rivers of west Africa, and the Mozambique (Philypnodon grandiceps), Dwarf flatheaded mouth-brooder (Oreochromis mossambicus), gudgeon (Philypnodon sp.), Australian smelt native to the eastern coastal rivers of southern (Retropinna semoni), Murray-Darling rainbowfish Africa from the Zambezi River south to the (Melanotaenia fluviatilis) and a number of Eastern Cape (Skelton 2001). Tilapia mariae is crayfish species includingM arron (Cherax generally restricted to latitudes north of the cainii), Gilgies (Cherax quinquecarinatus), Yabby Mulgrave River in Queensland (Anon. 2001), as (Cherax destructor), Bush yabbies (Geocharax it is intolerant of colder water temperatures, spp.) and possibly the threatened Swamp yabby and so is not considered a threat to the MDB. (Gramastacus insolitus) (Hutchison 1991; Pen & A population of T. mariae is present in Victoria, Potter 1992; Hutchison & Armstrong 1993; Pen et though restricted to an artificially warm habitat, al. 1993; Morgan et al. 2002, 2005; Hammer 2004; receiving thermally polluted warm water Weatherley 1963, 1977; Raadik & discharged from a power station (Cadwallader Backhouse in press). et al. 1980). Oreochromis mossambicus (Figure 2) is widespread in northern Queensland , around Brisbane in south east Queensland and within

24 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006

Figure 2. Mozambique mouthbrooder (Oreochromis mossambicus) from the Lyndon River in Western Australia. Photograph: D. Morgan.

parts of the Indian Ocean (Pilbara) Drainage (temperature, salinity, DO) and has flexible Division of Western Australia where it is currently habitat requirements. The species survives in restricted to the Chapman, Gascoyne, Minilya and temperatures between 8-42 °C, is active above Lyndon rivers (Arthington et al. 1984; Arthington 16 °C and breeds at temperatures of 20-24 °C 1986; Arthington & Blühdorn 1994; Morgan et al. (Mackenzie et al. 2001, Skelton 2001). While 2004). Due to the very close geographic proximity naturally found in closed estuaries and coastal of the species to the MDB (where it is within 100s reaches of rivers, as well as inland regions in of metres of the Basin in headwater tributaries south-eastern Africa (Skelton 2001), it has been of the Burnett River catchment) it is likely to be a recorded in WA at salinities up to 95ppt in the future invader of at least the northern reaches of Lyndon River and found near the mouth of the the system. Chapman River estuary (Morgan et al. 2004). Growth of populations and individuals is often Ecology rapid. For example, from 6-8 fish released into The Mozambique mouthbrooder is a moderate- an ornamental pond in Cairns 18 months prior sized fish that attains a maximum total length of to rotenone treatment, 12.5 ton of fish approximately 500 mm and 3 kg (Skelton 2001), were removed! but it is often much smaller and is known to form populations of stunted individuals with early sexual maturity (3 months, 50 mm TL). Paternal care through mouth brooding in the species facilitates a high survival of offspring. It is mainly herbivorous, but will eat macroinvertebrates and occasionally fish (Aravindan 1980; Arthington and Bluhdorn 1994; Webb 2006). The species also has wide physiological tolerances

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 25

Figure 3. Oriental weatherloach (Misgurnus anguillicaudatus). Photograph: G. Schmida.

Impacts macrophytes while feeding on periphyton, and Aspects of their population ecology, such as they may eliminate submerged and emergent mouth brooding, and ability to breed all year macrophytes by grazing or by uprooting plants round allow for very rapid population growth (Lahser 1967). There is little data available on and wide tolerance to varying environmental competition for food between Mozambique regimes allows the species to dominate a fish mouthbrooder and Australian native fish species, fauna in abundance and biomass very quickly and however the diet of juvenile O. mossambicus in makes them a highly effective invader of rivers the Chapman River (WA) and mature fish in the (including estuaries), lakes and wetlands. This Gascoyne River was dominated by detritus, while also has ramifications for recreational fisheries some aquatic are also taken (Maddern where the species may dominate more desirable 2003; Morgan et al. 2004). The species’ success recreational species. Both male and female is also attributed to being able to utilise detritus, individuals are aggressive during the spawning which in most systems dominates the substrate. season; nests are built and occur in high densities There is also some potential for this species e.g. ~80% of shallows were covered in nests in the to spread diseases and parasites to native fish species. Gascoyne River (WA) (Morgan et al. 2004). Males defend the nests and are aggressive towards other fish in the nesting area.S uch aggressive behaviour may exclude native fish from large sections of river, and the area occupied by nests may limit habitat available to native fish (Cooper and Harrison 1992; Morgan et al. 2004) and this is of great concern in arid areas where small pools act as vital refuges for native fishes.T he species has been reported elsewhere to kill aquatic

26 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Oriental weatherloach Ecology (Misgurnus anguillicaudatus) In Australia, Oriental weatherloach is a bottom- A detailed review of the taxonomy, biology and dwelling, cryptic species with no known migratory ecology of the Oriental weatherloach (Figure 3) movements. Data from Japan suggests that a in its native range, and in Australia, has been proportion of adults move from streams into recently been undertaken by Koster et al. (2002). paddy fields to spawn, with the adults and juveniles subsequently returning to streams Which weatherloach in Australia? (Tanaka 1999). Weatherloach is a habitat Misgurnus loaches are highly variable in generalist, occurring in still lakes or ponds, morphology and coloration with in excess of 30 drains, rivers, creeks, and billabongs. Habitats species described. Approximately four species can be vegetated or un-vegetated, permanent are currently recognised as valid, but there is or temporary, with substrates including cobble, disagreement between researchers (Koster et al. pebble, gravel, sand, mud and detritus. Their 2002). The four valid species are: habitats range from clear, upland, cobble- bottomed streams (Cotter River, ACT) to lowland - M. anguillicaudatus turbid rivers (Murray River) and billabongs, and - M. cestoideus habitats can be natural, modified, or degraded. - M. bipartitus They can often be found in sandy or silty habitats - M. mizolepis with accumulations of leaf litter, organic debris or root mats, usually in backwater or Weatherloach have been introduced to Australia low-flow areas. via the aquarium trade with approximately 50,000 fish imported annually in the early 1980s Oriental weatherloach is less active during cooler before importation was banned in 1986. The periods, is tolerant of poor water quality and taxonomic keys are poor, and potentially all four withstands very low levels of dissolved oxygen, Misgurnus species were imported. It is currently and are known to hibernate and aestivate, assumed that the majority of imports were of M. burrowing into the sediment. They are capable anguillicaudatus, and that this is the only species of surviving for lengthy periods without free established in Australia (Koster et al. 2002). water, and are often excavated from tunnels at depth from the bottom of dry dams, billabongs, Distribution irrigation channels, creeks and drainage lines, etc. It is eurythermic, commonly recorded from Oriental weatherloach is a small, elongate waters with temperatures ranging from 2 to fish with a maximum length 200–250 mm, but 30ºC, and have been recorded from thermal usually is less than 180 mm TL in Australia springs at up to 42ºC. The species is omnivorous, (Figure 3). It has established populations in a with the diet containing aquatic invertebrates, number of countries outside its natural range, microcrustaceans, molluscs, gastropods and including the USA, Germany, Philippines, Palau some algae and plant material. It feeds by using and Italy (Koster et al. 2002; Raadik et al. 2005). It was first recorded in the wild in Australia in 1980 in the Australian Capital Territory (Lintermans et al. 1990) and a self-sustaining population was Figure 4. Known occurrences of Oriental weatherloach known from the Yarra River in Victoria by 1984 in Australia to 2003. Further information on expansion of (Allen 1984). Populations are now known from the distributional range over time is in Koster et al. 2002. NSW, Vic and the ACT (Figure 4). A previous population from an urban creek in Brisbane was &.-%"'%%( eradicated in 1990 (Lintermans & Burchmore 1996, Koster et al. 2002, Raadik et al. 2005). There are single, unconfirmed records of the species from SA and WA (see Koster et al. 2002).

% '%% @^adbZigZh C

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 27 a combination of chemical and tactile cues and has Due to their high population abundance in many five pairs of barbels around the mouth to locate areas, additional specific ecological impacts, food. Oriental weatherloach is a multiple spawner; currently unsubstantiated due to lack of research, females shed from 4000–8000 small, demersal are proposed: and adhesive eggs per spawning, usually laid • direct predation on native fish, and possibly on aquatic vegetation or on mud between plant frogs eggs and tadpoles; roots. Spawning occurs from spring to summer, • competition for food and space with native when water temperatures are between 20–30ºC species, particularly in drying habitats; (with 25ºC optimal). Males mature at 1 yr (110 mm TL) and females mature at 1-2 yrs (125 mm TL) • predation on larval/juvenile fish. (Lintermans & Burchmore 1996; Koster et al. 2002; Due to their high abundance in billabong habitats, Raadik et al. 2005). Oriental weatherloach has also caused minor economic loss by blocking irrigation pump inlets. Impacts Oriental weatherloach is an effective invader of flowing and still–water habitats.S pecific ecological Dispersal of impacts on native flora and fauna by this species Introduced Fishes in Australia are currently unknown, though the Lintermans (2004) identified 12 major vectors for apparent exclusion of the native fishM ountain human-assisted dispersal of alien freshwater fish galaxias has been noted. Mesocosm experiments in Australia, of which 10 are potentially relevant have also demonstrated significant reductions to the three fish species considered here (Table in aquatic invertebrate biomass and diversity 1). Dispersal via deliberate legal stocking is not at Oriental weatherloach densities of 4.3 fish/ conducted for Tilapia, Redfin perch or Oriental m2. The same experiments also demonstrated weatherloach, and the spread via contaminated elevated ammonia, nitrogen and turbidity levels ballast water is also considered unlikely, so need at fish densities of 4.3 fish/m2. The impacts of not be further considered. However, each has weatherloach on nitrogen and turbidity levels were been released through non-sanctioned releases similar to those reported for the introduced Carp through either illegal stocking, and potentially (Cyprinus carpio) (Keller & Lake in press). They have through bait bucket introductions, as escapees also been found to possess a number of parasites from ornamental or farm ponds or water not previously recorded from Australia (Dove & diversions. Management of vectors is an important Ernst 1998), and whilst most parasites are host issue that must be addressed as a high priority if specific, others such as the Asian FishT apeworm the spread of these species is to be contained or (Bothriocephalus acheilognathi) have been recorded managed. It must also be recognised that these from more than 100 species worldwide (Salgado- dispersal vectors are not independent, and the Maldonado & Pineda-López 2003) including behavioural drivers behind the vectors are varied, Australian native fish (Doveet al. 1997).

Table 1. Vectors for dispersal of alien fish in Australia, and whether they apply toR edfin perch,T ilapia and Oriental weatherloach (proposed major vectors highlighted with double tick marks).

Vector Redfin Tilapia Weatherloach Contaminant of Bait bucket introductions Transfers via water diversions (potential) (potential) Discarding aquarium fish Escape from aquaculture Bio control Deliberate illegal stocking Escape from outside ponds Transfer on commercial fishing gear Deliberate release for cultural reasons

28 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 poorly understood, and will need significant • How do we control vectors for dispersal of this input from the social sciences if mitigation is to species (still a popular recreational species in be effective. For example, Redfin perch in the some areas)? Canberra region were legally stocked in the 1950s, • What are the feasible control options for subsequently illegally stocked into ponds and farm this species? dams, from where they have escaped and invaded • Are there potential breeding or recruitment the majority of lowland streams (Lintermans ‘hotspots’ or conditions which could be et al. 1990). targeted to reduce abundance? Knowledge gaps Mozambique mouthbrooder (Tilapia) The Mozambique mouthbrooder is not yet In most cases and particularly within the MDB established in the Basin, but the Basin is the impacts of the three species are largely vulnerable to translocations from nearby coastal speculative and unquantified.H owever, the drainages in Queensland. Key questions that need application of the precautionary principle to be addressed for this species are: indicates the need to control the species even • How much of the Basin is vulnerable to though complete knowledge of the impacts invasion from Tilapia (based on is lacking. temperature tolerance)? If the impacts of these three alien fish species • Will the critical temperature requirements of are to be managed appropriately, and adequate Tilapia change with time (i.e. will they slowly resources devoted to such management, the acclimate to colder water temperatures)? following significant knowledge gaps need to be addressed. Some knowledge gaps are common • What are the dietary interactions with across all three species, whilst others are Australian native fish species? species specific. • What are the impacts of Tilapia on macrophytes in Australia? Redfin perch • How do we control vectors for dispersal of Redfin perch is a long-established alien species this species (still being used illegally for bait, whose impacts on native species are not well released in farm dams etc)? known. Its value as a recreational fishing target in • What are the feasible control options for some areas has deflected attention away from its this species? detrimental impacts. Significant knowledge gaps include: Oriental weatherloach • Current distribution and abundance within The biology, ecology and environmental impacts the Basin. of this rapidly spreading, environmentally • Potential differential impacts in lotic vs tolerant and highly abundant species in lentic waters. Australia have been poorly studied and require • Predation effectiveness (particular life-history urgent investigation. Its potential distribution stages, particular native species, is unlimited in the Basin, and it is still being or opportunistic) used illegally for bait. Important ecological and biological knowledge gaps, which may assist in • Potential interaction between the impacts from Redfin perch and with climate variability control of the species are: (i.e. do droughts exacerbate predation impact • Which species of weatherloach occur of Redfin by concentrating native species in in Australia? refuges or impoundments?) • Improved understanding of ability to survive • What are the effects of EHN Virus in the desiccation. How long can the species live wild (e.g. it is known that Macquarie perch out of water and associated implications for populations are still surviving in catchments control options (ie. how do you control an where the virus has been confirmed)? animal that is buried 1m below the base of a dry dam or creek bed)? • Are there impacts of Redfin perch on native fish stocking programs (impacts on trout • Are there control options when the species is stocking programs are known but little is aestivating and thus would we benefit from known of the threat to native fish stocking) examining depths of fish in aestivation?

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 29 • Tolerances of, and reactions to piscicides and other potential chemical-based control agents. References Allen, S. 1984. Occurrence of juvenile weatherfish • Upstream movement and recolonisation potential. Misgurnus anguillicaudatus (Pisces: Cobitidae) in • Ability to survival and persist at higher elevations the Yarra River. Victorian Naturalist 101(5): 240–242. in Australia. Allendorf, F. W. & Lundquist, L. L. 2003. Population • Salinity tolerance of life-history stages. biology, evolution, and control of invasive species. Conservation Biology 17(1): 24–30. • Detailed diet studies in Australian environments. Anonymous 2001. Control of exotic pest fishes. • Their importance in the food chain of native An operational strategy for Queensland waters fish communities, including potential life- 2000–2005. Queensland, Department of Primary stages targeted by piscivorous fish; knowledge Industries. of predator-prey interactions and how habitat Arthington, A.H. 1986. Introduced cichlid fish in complexity may mediate this interaction. Australian inland waters. In De Decker, P. and Williams, W.D. (eds) Limnology in Australia. CSIRO, • Potential differential impacts in billabongs and Melbourne and Junk, Dordrecht. Pp 239-248. streams. (This would assist in prioritisation of Arthington, A. & McKenzie, F. 1997. Review control works). Is impact density dependant? of impacts of displaced/introduced fauna • Understanding and control of vectors associated with inland waters. Australia: State responsible for dispersal. of the Environment Technical Paper Series (Inland Waters). Canberra, Department of the • Feasible control options in lotic and Environment. lentic environments. Arthington, A.H., McKay, R.J., Russell, D.J. & Milton, D.A. 1984. Occurrence of the introduced cichlid Oreochromis mossambicus (Peters) in Queensland. Australian Journal of Marine and Conclusions Freshwater Research 35: 267–272. The specific impacts of some of the three Arthington, A.H. & Blühdorn, D.R 1994. Distribution, genetics, ecology and status of the alien species considered here are still largely introduced cichlid, Oreochromis mossambicus, in unquantified, due mostly to a lack of specific Australia. Mitt. Internat. Verein. Limnol. 24: 53–62. research. There is very little knowledge of Aravindan, C.M. 1980. Food selection and feeding interactions between impacts and habitats (i.e. habits of Tilapia mossambica Peters in different different impacts in lotic vs lentic environments), ecological habitats. Proceedings of the Indian climate (wet/dry years), or river regulation (higher National Science Academy B46(1): 54-57. resilience of ‘natural’ environments). There is a Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide relatively limited range of control options currently to Freshwater Fish of Victoria. Victorian Government available, and further efforts need to be made Printing Office,M elbourne. to facilitate the development, refinement, or Cadwallader, P.L., Backhouse, G.N. & Fallu, R. application of such methods. Effective management 1980. Occurrence of exotic tropical fish in the of dispersal vectors, including social issues, cooling pondage of a power station in temperate education and uniform legislative controls, is a south-eastern Australia. Australian Journal of Marine and Freshwater Research 31: 541-546. major issue worldwide, and until we understand the underlying social reasons for the introduction and Clements, J. 1988. Salmon at the Antipodes: A History and Review of Trout, Salmon and Char and dispersal of alien fish, management efforts may be Introduced Coarse Fish in Australasia. Published by poorly targeted. the author. Finally, the question is whether there is a need Cooper, J.A.G. & Harrison, T.D. 1992. Effects of to definitively know the specific impacts of each nesting activities of Oreochromis mossambicus alien fish species, or whether you simply apply (Pisces: Cichlidae) on bank stability in small the precautionary principle (based on reasonable lagoons. South African Journal of Science 88: 398- 401. suspicion of impacts) and commence management actions to control or mitigate the threat. Dove, A.D.M., Cribb, T.H., Mockler, S.P. & Lintermans, M. 1997. The Asian fish tapeworm, Bothriocephalus acheilognathi, in Australian freshwater fishes.Marine and Freshwater Research 48: 181–183.

30 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Dove, A.D.M. & Ernst, I. 1998. Concurrent Langdon, J.S., Humphrey, J.D., Williams, L.M., Hyatt, invaders – four exotic species of Monogenea A.D. & Westbury, H.A. 1986. First virus isolation now established on exotic freshwater fishes in from Australian fish: an iridovirus-like pathogen Australia. International Journal for Parasitology 28: from redfin perchPerca fluviatilis L. Journal of Fish 1755–1764. Diseases 9: 129–135. Fuller, P.L., Nico, L.G. & Williams, J.D. 1999. Langdon, J.S. & Humphrey, J.D., 1987. Epizootic Nonindigenous fishes introduced into inland haematopoietic necrosis, a new viral disease in redfin waters of the United States. American Fisheries perch Perca fluviatilis L., in Australia. Journal of Fish Society, Maryland, U.S.A. Diseases 10: 289–297. Hammer, M. 2004. The Eastern Mt Lofty Ranges Lintermans, M. 2004. Human-assisted dispersal Fish Inventory: Distribution and Conservation of of alien freshwater fish in Australia.New Zealand freshwater Fishes of Tributaries to the Lower Journal of Marine and Freshwater Research 38: Murray River, South Australia. Native Fish 481–501. Australia (SA) Inc. & River Murray Catchment Lintermans, M. in press. Fishes of the Murray-Darling Eater Management Board. Basin: an introductory guide. Murray-Darling Basin Hutchinson, M.J. 1991. Distribution patterns of Commission, Canberra. redfin perchPerca fluviatilis Linnaeus and western Lintermans, M., & Burchmore, J. 1996. Family pygmy perch Edelia vittata Castelnau in the Murray Cobitidae: Loaches. In: McDowall, R. M. (ed.). River, Western Australia. Records of the Western Freshwater Fishes of South-eastern Australia. REED Australian Museum 15: 295-301. BOOKS. Sydney. Pp 114–115. Hutchinson, M.J. & Armstrong, P.H. 1993. The Lintermans, M., Rutzou, T., & Kukolic, K. 1990. invasion of a south-western Australian river Introduced fish of the Canberra region - recent system by Perca fluviatilis: history and probable range expansions. In D. Pollard (ed.), Australian causes. Global Ecology and Biogeography Letters 3: Society for Fish Biology Workshop: Introduced and 77-89. Translocated fishes and their Ecological Effects. Bureau Keller, R.P. & Lake, P.S. in press. Potential impacts of Rural Resources Proceedings No. 8, Australian of a recent and rapidly spreading coloniser of Government Publishing Service, Canberra. Pp 50–60. Australian freshwaters: Oriental weatherloach McDowall, R.M. 1996. Family Percidae: Freshwater (Misgurnus anguillicaudatus). Ecology of Freshwater perches Pp 183–185 in McDowall, R.M. (ed.) Fish Freshwater Fishes of South-eastern Australia. Second Koehn, J.D. & Mackenzie, R.F. 2004. Priority edition. Reed Books, Australia. management actions for alien freshwater fish MacKenzie, R., Jackson, P. & Cotterell, E. 2001. species in Australia New Zealand Journal of Marine Control of exotic pest fish, an operational strategy for and Freshwater Research. 38: 457–472. Queensland freshwaters 2000-2005.Department of Koster, W.M., Raadik, T.A. & Clunie, P. 2002. Primary Industries,Queensland. Information Series Ql Scoping study of the potential spread and impact of 01005. Pp15-16. the exotic fish Oriental weatherloach in the Murray- Maddern, M. 2003. The distribution, biology and Darling Basin, Australia: a resource document. ecological impacts of three introduced freshwater Report to Agriculture, Fisheries, Forestry, Australia teleosts in Western Australia. Unpublished Honours under Murray-Darling 2001 FishRehab Program. thesis, Murdoch University, Western Australia. Victoria, Freshwater Ecology, Arthur Rylah Institute MDBC 2004. Native Fish Strategy for the Murray- for Environmental Research. (Available at: http:// Darling Basin 2003-2013. Murray-Darling Basin www.dse.vic.gov.au/dse/nrenari.nsf/home+page/ Commission, Canberra. DSE+ARI~Home+Page?open, go to ‘Publications and Downloads’, then ‘Scientific reports and Morgan, D.L., Hambleton, S.J., Gill, H.S. & Beatty, Software’, then down to ‘Invasive Species’. S.J. 2002. Distribution, biology and likely impacts of the introduced redfin perch Perca( fluviatilis) Lahser, C.W. 1967. Tilapia mossambica as a fish for (Percidae) in Western Australia. Marine & Freshwater aquatic weed control. Progressive Fish Culturalist Research 53: 1211–1221. 29: 48-50. Morgan, D.L., Gill, H.S., Maddern, M.G. & Beatty, Langdon, J.S. 1989a. Prevention and control of fish S.J. 2004. Distribution and impacts of introduced diseases in the Murray-Darling Basin. Pp 163–172 freshwater fishes in Western Australia.New Zealand in: Proceedings of the Workshop on Native fish Journal of Marine and Freshwater Research 38: Management, Canberra, 16–18 June 1988. Murray- 511–523. Darling Basin Commission, Canberra. Morgan, D., Lintermans, M. & Raadik, T. 2005. Shame Langdon, J.S. 1989b. Experimental transmission File: Alien Creature Feature (No. 2): Redfin Perch. and pathogenicity of epizootic haematopoietic Australian Society for Fish Biology Newsletter 35 (2): necrosis virus (EHNV) in redfin perchPerca 82–87. fluviatilis L., and 11 other teleosts. Journal of Fish Diseases 12: 295–310. Moyle, P.B. & Light, T. 1996. Biological invasions of fresh water: empirical rules and assembly theory. Biological Conservation 78: 149–161.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 31 Pen, L.J. & Potter, I.C. 1992. Seasonal and size- related changes in the diet of perch, Perca fluviatilis L., in the shallows of an Australian river, and their implications for the conservation of indigenous teleosts. Aquatic Conservation: Marine and Freshwater Ecosystems 2: 243-253. Pen, L.J., Potter, I.C. & Calver, C.C. 1993. Comparisons of the food niches of three native and two introduced fish species in an Australian river. Environmental Biology of Fishes 36: 167-182. Raadik, T.A., & Backhouse, G. in press. Field Guide to the Freshwater Fishes & Decapod Crustaceans of Victoria. Raadik, T.A., Koster, W. & Lintermans, M. 2005. Shame File: Alien creature feature No. 1, Oriental weatherloach Misgurnus anguillicaudatus (Cantor, 1842)(Pisces: Cobitidae). Australian Society for Fish Biology Newsletter 35(1): 55–8. Rahel, F.J. 2002. Homogenization of freshwater faunas. Annual Review of Ecology and Systematics 33: 291–315. Salgado-Maldonado, G. & Pineda-López, R. 2003. The Asian fish tapewormBothriocephalus acheilognathi: a potential threat to native freshwater fish species in Mexico. Biological Invasions 5: 261–268. Skelton, P. 2001. A complete guide to the freshwater fishes of southern Africa.S truik Publishers, Cape Town, South Africa. Tanaka, M. 1999. Influence of different aquatic habitats on distribution and population density of Misgurnus anguillicaudatus in paddy fields.Japanese Journal of Ichthyology 46(2): 75-82. Weatherley, A.H. 1963. Zoogeography of Perca fluviatilis Linnaeus and Perca flavescens Mitchill, with special reference to the effects of high temperature. Proceedings of the Zoological Society of London 141: 557–576. Weatherley, A.H. 1977. Perca fluviatilis in Australia: zoogeographical expression of a life cycle in relation to environment. Journal of the Fisheries Research Board of Canada 34: 1464–1466. Webb, A.C. 2006. Taxonomy, distribution, ecological, social and economic impacts and treatment of the tilapiine , the Mosambique mouthbrooder,Oreochromis mossambicus and the Black-spotted mangrove cichlid, Tilapia mariae: a review. Report prepared for the Department of Primary Industries and Fisheries: 50pp. Whittington, R.J., Kearns, C., Hyatt, A.D., Hengstberger, S. & Rutzou, T. 1996. Spread of epizootic haematopoietic necrosis virus in southern Australia. Australian Veterinary Journal 73(3): 112–114.

32 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Management of pest fish

Mike Braysher Institute for Applied Ecology, University of Canberra, ACT 2601.

Abstract Introduction What makes a fish a pest? Answer, when the fish What makes a fish a pest?I t depends is in conflict with human interests. Pest fish can very much on who is making the decision. For be non-native or native (for example, translocated example, studies have shown that trout are native species).The pest status of a fish is likely voracious predators of some native fish and are to change with the interests of the assessor. An seen as a key threatening process (Cadwallader aquatic biologist may regard trout as a serious 1996). Yet many state fishery agencies still stock pest while to a recreational fisher they are a rivers and lakes with trout and protect them valued resource. during their breeding season. They are therefore Management of pest fish should focus on the a highly valued resource. Pest fish may variously desired outcome from management, not just on be destructive, a nuisance, out of place or simply killing pest fish.T he outcome may be reduced not wanted. The more accurate answer to the turbidity, recovery of native fish populations question “What is a pest fish?” is “A fish that and/or improved recreational fishing.H ighest is in conflict with human interests – because it management priority should be given to causes significant damage to a valued resource” preventing the establishment of additional (Braysher 1993; Olsen 1998). species and limiting the spread of those that are The pest status of a fish can change with time, not fully established. For established species, between areas or according to the perception of management should be based on an integrated the assessor. Under this definition, native fish and strategic approach that addresses the range and other aquatic organisms that have been of factors that threaten the health of native fish translocated outside their natural range can populations and health of the Murray-Darling become pests. Basin generally. Ideally this should be part of an There are several aquatic species in the Murray- integrated river restoration program. Darling Basin that are of concern. Until recently, Management techniques for pest fish include the attitude towards pests was to try and kill physical removal, chemical control, as many as possible. Each year hundreds of exclusion devices, habitat manipulation, thousands of carp are trapped, poisoned or rehabilitation of river systems and genetic caught by fishermen.T he hope had been that if manipulation techniques. there was sufficient concerted effort to remove as Because eradication of established pest fish is many carp and other pest fish as possible, they rarely possible (ie. the permanent removal of could be all but eliminated or even eradicated. every individual), management needs to balance However, we now know that it is unlikely and the costs and benefits of interventions. Besides unrealistic that established pest fish can be local eradication, management options include eradicated, that is, the permanent removal of strategic management (one-off control, sustained every last individual. The possible exception is in management, targeted management) or no some local situations where the populations are management. All too often management is ad isolated and relatively low (Koehn and McKenzie hoc with little strategic planning and little or no 2004; Lintermans 2004). Several conditions monitoring and evaluation. need to be met for eradication to be possible

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 33 (Bomford and O’Brien 1995). It is sobering to note The next step is to determine who has the that no established widespread pest has ever problem and who is responsible for addressing been eradicated from Australia.The success of it and then to develop and implement strategies pest fish in Australia is due to aspects of their to achieve that outcome or a combination of biology, habitat changes that provide them with outcomes. good conditions, and few diseases and predators (Olsen 1998, Koehn and McKenzie 2004; Lintermans 2004). Like most pest animals, pest Management Approach fish can rapidly recover their numbers following Many groups and individuals have an interest knockdown due to adverse climatic conditions in pest management. They include farmers, or control operations (Olsen 1998). Most do well nature reserve managers, financial institutions, in human disturbed systems. For example, the government agencies, animal welfare and Murray-Darling Basin (MDB), produces about nature conservation groups (Figure 1). Failure 40% of Australia’s primary production. As might to adequately consult and take into account the be expected for such an important production views of the major players when planning and area, there have been extensive changes to the conducting pest management, can undermine environment, many of which favour pest fish but the chance of success (Olsen 1998). Relevant not native aquatic organisms (see Table 2). stakeholders need to be identified early Controlling the damage due to pest animals and be actively involved in the planning and including fish to an acceptable level is much more implementation of the program. Without an complicated than simply reducing pest numbers. inclusive, cooperative approach, there is unlikely Before starting, it is important to have a clear to be ownership of the problem and the solution understanding of the problem that pest fish are and hence effective management of the damage believed to cause. The problem should be defined due to pest animals is unlikely. in terms of desired outcomes. The problem In addition there are several factors besides pest may be disturbance of the breeding habitat of fish that need to be addressed in an integrated native fish, fouling of waterways due to periodic approach to achieve the desired management die-off of carp, poor water quality or complaints outcome, e.g. river rehabilitation (Figure 2). from recreational fishers of an over-abundance Koehn and Mackenzie (2004) provide an excellent carp. Killing pest fish might be the best way, review of the issues and approach required for but excluding carp from important native fish effective management of pest fish in Australian breeding sites or re-snagging sections of river to freshwater systems. Several strategic planning provide cover and breeding habitat for native fish documents that provide the basis for a systematic may be better and more cost effective in the long and strategic approach to managing pest fish, run, especially given the capacity of pest fish to including the Queensland Pest Animal Strategy rapidly recover their numbers (MDBC 2002; 2003). (Qld DPI 2002), the Action Plan for Alien Species In other cases, the problem may be based on a in the MDB (MDA 2003), the Native Fish Strategy misconception and the best strategy may be a for the MDB 2003-2013 (MDBC 2004), and guides targeted education program. for setting priorities and developing local Table 2. Some of the changes humans have caused management plans (Braysher and Barrett 2000; to the MDB (McLennan 1996) Braysher and Saunders 2003).

80% of Murray-Darling water is regulated. Management techniques High nutrient load causing toxic algal blooms. There are a range of techniques and strategies that can be used to control the damage due to introduced Salinity - 18 fold increase between Yarrawonga (Vic) fish (Table 3). Further research might increase the and Morgan (SA). efficiency of the techniques, but current methods Construction of dams and weirs. are unlikely to be replaced by high-tech, “magic Removal of river bank trees. bullets”, at least not in the short term. Effective control of the damage due to pest fish is possible De-snagging of river bed. provided the available techniques are applied Use of chemicals for agriculture. strategically, usually in combination and taking into Recreational and commercial fishing. account the range of other factors that influence the Introduced fish. biotic and abiotic health of the river system.

34 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Prioritising actions to manage the threat from introduced fish Once introduced fish are established, it is very difficult to reduce their numbers let alone eradicate them. The highest priority for management is to have a strategy in place to prevent the introduction and establishment of new species and, if a new outbreak is detected, to eliminate it while numbers are low. For established species, management needs to be strategically applied since the application of available techniques is usually expensive and can disrupt other uses of the aquatic system. Rarely can techniques be applied across the total area over which the unwanted fish occurs, at least not concurrently. Management may achieve the best outcome by targeting areas where introduced fish concentrate and/or breed.

Figure 1. Some of the stakeholders involved in management of pest fish

Government land, water, fisheries Landholders environment protection and nature conservation agencies Local government

Recreators Commercial fishers Effective pest fish management Catchment managers Conservation groups

Recreational anglers Researchers

Rivercare landcare groups Individuals

Figure 2. Some of the actions required to rehabilitate a river system

Nutrient management Restoration of fish passage

Pest fish control Improving biodiversity River rehabilitation Cap on diversions Environmental flows

Improving water quality Restoration of instream habitat

Riparian zone management Management of native fish

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 35 Table 3. Techniques for managing the damage due to introduced fish (based on Koehn et al. 2000; Braysher and Barrett 2000).

Technique Comment Capture and removal of pest fish, including: In some cases commercial harvesters can be used to • Electrofishing reduce costs. Commercial harvest usually only targets • Nets fish of marketable size and condition. On its own, capture • Traps in fishways or streams and removal, whether commercial or not, is unlikely to • Intensive line fishing reduce populations to a level where damage is acceptable. Remaining fish can quickly recover unless other strategies are used to further reduce the population and maintain it at low levels. Factors such snags can limit the use of techniques such as nets. Chemicals (eg. Rotenone) Chemical poisoning of fish has been used to eradicate or control isolated populations of pest fish.H owever, poisons are relatively non-specific and rarely can be used for broad-scale management. Habitat manipulation, including: While they have potential, their value for broad-scale • Draining waterways and removing carp management is still to be fully evaluated. • Draw down of fish breeding areas to expose and kill eggs. Rehabilitation of the aquatic system to encourage native The primary aim is to restore habitat so that it is more fish including predatory species, including: suitable for native species, especially predatory fish and to • Restoring riparian vegetation. reduce the suitability of the habitat for non-native species. • Re-snagging sections of river. • Reducing the impact of cold-water pollution. Bio-manipulation. (eg. to increase the population of native The potential impacts from stocking native predators predatory species such as golden perch and Murray cod). needs to be carefully assessed. The system may not support the additional biomass and there may be undesired impacts on other parts of the system due to increased predation. Translocation principles should be followed (MCFFA 1999). Disease agents, including: Potential non-target impacts from such agents need to be • Parasites assessed. No suitable disease agent is currently available. • Viruses • Bacteria Fish exclusion devices, including: Screens have had success in some areas but require • Fish screens on outlets from impoundments continual maintenance to prevent blockage by debris and • Electrical barriers can be breeched by high water flows.T he effectiveness of • Bubble curtains other devices has not been assessed for large-scale use. • Sonic devices Molecular and similar biological techniques, including: Techniques are in the early stages of development and • Daughterless carp technology their effectiveness difficult to gauge.M ost effort is on the • Lethal genes daughterless carp technique. If shown to be effective, it is • Sterile offspring unlikely to be available for field use for many more years.

36 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Preventing the establishment of new species social outcomes for the area. The plans need to Several additional species of non-native fish and be locally developed and owned and implemented other aquatic animals could establish in the MDB by those that have the greatest stake in the (Bomford and Glover 2004; see Bomford page 60 results and whose time and resources will mostly this publication). It is important to develop and test be required. A whole-of-system approach is a system that incorporates an appropriate risk required. Managers need to determine where to assessment process supported by enforceable best put their limited resources to get the best regulation to prevent new introductions in return. Guides have been developed to assist local Australia (Bomford 2003). However, there are groups to determine priority areas for action and already many species in captivity in Australia to develop and implement a locally owned plan which could establish (QLD DPI 2000). There are to manage the damage due to introduced fish others that are established in some waterways and other pest animals (Braysher and Barrett but which could spread to others such as the 2000; Braysher and Saunders 2003). The guides MDB. Of notable concern is Tilapia. This species promote integration of national, state, regional has been recorded in the upper reaches of the and local action plans to control pest animals MDB in Toowoomba (MDBC 2001), but apparently including introduced fish so that actions in one failed to establish. An Alert and Rapid Response catchment are not compromised by actions in Strategy is required that can detect and rapidly another (Koehn and Mackenzie 2004). At the respond to eradicate new incursions. local level, it is suggested that the area to be treated be broken into separate management Setting priorities to manage units in recognition that each unit often requires established species a specific management approach, and usually a different set of techniques (Figure 3). A ranking Management of established pest fish should system based on the threat of introduced fish to focus on reducing the damage that they cause biodiversity and production can help managers to an acceptable level. Plans should be based decide where best to focus their resources. on a catchment or sub-catchment approach where the desired outcomes from pest fish management are clearly defined and related to the desired environmental, production and/or

Figure 3. Hypothetical Section of the Murrumbidgee River broken into management units

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Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 37 • publications, field days, workshops, weight of Measuring success - carp removed. monitoring and evaluation Indicators of outcomes – indicate whether the project is being successful. For example: It is very difficult to determine how effective the proposed management will be, not the least due • increases in native fish species and density of to introduced fish being only one of several factors water plants after pest fish control; that influence the health of theM DB. Almost • changes in community attitudes; and invariably, an integrated approach is required • improvement in water quality. that addresses the range of threats. Predicting Involving the local community in the monitoring the outcome from implementing amelioration program helps to maintain local ownership and strategies is also complicated because there enthusiasm for the management program as well are few studies that have clearly demonstrated as gathering essential information for those that the nature and quantified the extent of the need to assess the success of the program. The damage due to introduced fish. Without a good following can help to involve the local community understanding of the nature and the level of in monitoring: damage, it is difficult to determine the success or otherwise of management. Ideally experimental • Be very clear about what needs to be studies are required to obtain this information, monitored and why. but as a minimum, management programs • Keep it as simple as possible and compatible should include an appropriate monitoring and with other routine management practices. evaluation strategy that enables the effectiveness • Make the process quick and easy. of the management to be assessed. • Provide regular feedback to the community on Monitoring and evaluation helps to: results in an appropriate format. • determine whether the objectives and the • Display or disseminate the results in a management strategy were appropriate; public place. • improve the focus and procedures of a project Appropriate and regular reporting, especially if as it proceeds; it includes feedback on successes, interesting • develop the skills and understanding of people information on local members of the group or involved in a project; interesting information on pest fish management • provide information for planning a new from elsewhere can help keep group members project; and involved and informed on progress with the program. • justify and promote a project to the wider community. Monitoring and evaluation programs should References be specifically tailored to each pest fish Bomford, M. 2003. Risk Assessment for the Import and management program. Some examples of what Keeping of Exotic Vertebrates in Australia. Bureau of might be monitored are: Rural Sciences, Canberra. Indicators of inputs – these record the resources Bomford, M. and Glover. J. 2004. Risk assessment that the project is using and can indicate how model for the import and keeping of exotic freshwater resources may be used more efficiently.T hese and estuarine finfish. A report produced by the inputs include: Bureau of Rural Sciences for The Department of Environment and Heritage. • project finances; and Bomford, M. and O’Brien, P. 1995. Eradication or • time, materials, equipment and funding control for vertebrate pests? Wildlife Society Bulletin contributed by the community. 23: 249-255. Indicators of outputs – these record progress and Braysher, M. 1993. Managing Vertebrate pests: the level of activity, including: Principles and Strategies. Bureau of Resources Sciences, Canberra. • whether the project is being implemented Braysher, M. and Barrett, J. 2000. Ranking areas for on schedule; action. A guide for carp management groups. Murray- • the observations, feelings and concerns of Darling Basin Commission, Canberra. the people involved in the project (employees, volunteers, project managers) about how will it is working; and

38 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Braysher, M. and Barrett, J. 2001. Report on the workshop for the management of tilapia in the northern Murray-Darling Basin, Toowoomba, 2-3 April, 2001. Murray-Darling Basin Commission, Canberra. Braysher, M. and Saunders, G. 2003. PESTPLAN – a guide to setting priorities and developing a management plan for pest animals. Bureau of Rural Sciences and the Natural Heritage Trust, Canberra. Cadwallader, P. 1996. Overview of the impacts of introduced salmonids on Australian native fauna. Australian Nature Conservation Agency, Canberra. Carp Control Co-ordination Group. 2000. National Management Strategy for Carp Control 2000-2005. Murray-Darling Basin Commission, Canberra. Koehn, J., Brumley, A. and Gehrke, P. 2000. Managing the Impacts of Carp. Bureau of Rural Sciences, Canberra. Koehn, J. and MacKenzie, R. 2004. Priority management actions for alien freshwater fish species in Australia. New Zealand Journal of Marine and Freshwater Research, 38: 457-472. Lintermans, M. 2004. Human assisted dispersal of alien freshwater fish in Australia.New Zealand Journal of Marine and Freshwater Research, 38: 481-501. MCFFA. 1999. National Policy for the Translocation of Live Aquatic Organisms – Issues, Principles and Guidelines for Implementation. Ministerial Council on Forestry, Fisheries and Aquaculture. Bureau of Rural Sciences, Canberra. Mclennan, W. 1996. Australians and the Environment. Australian Bureau of Statistics Catalogue No 4601, Canberra. Murray-Darling Basin Commission. 2001. Report on the workshop for the management of Tilapia in the northern Murray-Darling Basin, Toowoomba, 2-3 April, 2001. MDBC, Canberra. Murray-Darling Basin Commission. 2002. Conceptual model to guide investments for restoring native fish in the Murray-Darling Basin. Report by the expert panel convened by the Murray-Darling Basin Commission, Canberra. Murray-Darling Basin Commission. 2004. Native fish strategy for the Murray-Darling Basin 2003-2013. Murray-Darling Basin Commission, Canberra. MDA and NCPFTF. 2003. Aliens in the Basin - An introduction to alien fish in theM urray-Darling Basin!” (June 2004) (8 page pamphlet). Olsen, P. 1998. Australia’s pest animals: New Solutions to old problems. Bureau of Rural Sciences and Kangaroo Press, Canberra. Qld DPI. 2000. Control of Exotic Pest Fishes - An Operational Strategy for Queensland Freshwaters 2000 – 2005. Department of Primary Industries and Fisheries, Qld. Qld NRM. 2002. Queensland pest animal strategy. Department of Natural Resources and Mines, Queensland.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 39 Summary of existing alien fish management (control) mechanisms in MDB jurisdictions

Jason Higham MDBC Native Fish Strategy Coordinator (SA), Rural Solutions SA, GPO Box 1671, ADELAIDE, SA 5001. [email protected]

• Improvement in regulation of aspects of the Abstract hobby/aquarium industry especially with The Murray-Darling Basin (MDB) jurisdictions regard to licensing non-permitted species have a range of legislation, policies and already present in Australia; and programs aimed at dealing with the threats • Adoption of the black and grey list as proposed posed by alien and exotic species, as in the Strategic Approach To The Management well as translocated native species. This Of Ornamental Fish In Australia – Consultation paper summarises the existing alien fish Draft (2005). management (control) mechanisms in MDB Alien species pose a significant challenge to all jurisdictions. This summary suggests that levels, including managers, scientists and the the major area of deficiency in alien species community. One of the major challenges facing management across jurisdictions is in the policy natural resource managers in all jurisdictions is response of jurisdictions to new infestations the management of the ‘desirable’ alien species and control of existing populations. (eg. Redfin perch and trout) to prevent adverse The paper proposes a series of initiatives and impacts, both direct and indirect, on native policies that could be employed to improve on fish species. these deficiencies, including: Whilst legislative frameworks for the • Improved investment in education management of alien species exist in each and awareness; jurisdiction, further work is needed on the • Adoption of uniform classification and development and implementation of regulations for alien species; effective policies. • Improved regulation and enforcement of human assisted dispersal ie use of fish as live bait; Introduction • The need for ongoing, intensive and rigorous The Murray-Darling Basin (MDB) is monitoring and control of populations as Australia’s largest river system that stretches soon as they are detected; across fiveS tates and Territories in Eastern Australia, including South Australia, Victoria, • An urgent need for a national policy and New South Wales, Queensland and the Australian approval for the use of rotenone to undertake Capital Territory. spot eradication of new infestations; These jurisdictions have a range of legislation, • Further development of other techniques policies and programs aimed at dealing with and transfer of knowledge for immediate use the threats posed by alien and exotic species, prior to approval of rotenone or in preference as well as translocated native species. The to rotenone; and Commonwealth government also has a role in • Further the immediate development of an the management of exotic and alien species alien species response framework for the through various legislation and import controls. Murray-Darling Basin; Each State and the Commonwealth have separate legislation related to management of alien and exotic species (hereafter referred to as aliens).

40 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Despite the borders of each state, they are all connected by the Murray-Daring river system, Legislation related to resulting in the potential of any alien species, the possession or release once established in a jurisdiction, being able to disperse from one state to another. Due to this of alien species and connectivity between states, any alien species enforcement capacity that becomes established could potentially inhabit the entire system and further spread from South Australia there or vice versa; spread from neighbouring In South Australia, the relevant legislation catchments into the Murray-Darling. regarding management of fisheries This paper summarises the existing alien fish resources is presently the Fisheries Act 1982 management (control) mechanisms in MDB (soon to be replaced by the Fisheries Management jurisdictions. The aim is to highlight differences Act 2007) and the associated regulations. It is an between jurisdictions and determine what actions offence under Section 50 of the Fisheries Act 1982 can be undertaken to minimise the risk posed by to release or permit exotic fish to be released alien species. Commonwealth legislation largely without the granting of a permit authorising that relates to import of potentially invasive species activity from the Director of Fisheries. rather than the response to and legislation It is also an offence under Section 49 of the for preventing further spread once introduced Fisheries Act 1982 to import or sell, purchase, into the country and hence is not discussed in deliver possess or control exotic species without this paper. For further information about the the granting of a permit authorising that activity Commonwealth legislation and management from the Director of Fisheries. The Fisheries (Exotic of ornamental fish in relevant jurisdictions see Fish, and Fish Diseases) Regulations A Strategic Approach To The Management Of 2000 contains a list of species for which permits Ornamental Fish In Australia – Consultation Draft will be granted by the Director of Fisheries (2005) which can be downloaded from Bureau of (Schedule 4) as well as a list of exotic fish to which Rural Sciences website at: section 49 does not apply (Schedule 3). www.affashop.gov.au/PdfFiles/ornament_fish6.pdf The sections of the Fisheries Act that refer to The author has exercised due care and skill in the possession or release of alien species also preparation and compilation of the information relates to all fish of that class whether they and data set out in this paper. Notwithstanding, be aquaculture or aquarium fish and acts as a the authors and contributors disclaim all liability, control for fish stocking. Fish stocking requires including liability for negligence, for any loss, approval from the Director of Fisheries under damage, injury, expense or cost incurred by any Section 50 (2) of the Fisheries Act 1982. person as a result of accessing, using or relying Fish species that are exotic for the purposes of upon any of the information or data set out in this Sections 49 and 50 are defined inS ection 5 (1) of publication to the maximum extent permitted by the Fisheries Act 1982. This states that unless the law and this paper should not be used as contrary intention appears: legal advice. “fish” means an aquatic organism of any Sincere thanks to the following people that species and includes the eggs, spat or spawn, or provided information contained within this the body, or part of the body (including the shell) paper from around the Basin: of such an organism; • Peter Jackson and Natalie Baker (QLD); “exotic fish” means fish of a class declared by • Mark Lintermans (ACT); regulation to be exotic fish. • Fern Hames (VIC), Brad Tucker and Lousie Galli (DPI); and • David Harasti and Sharon Molloy (NSW). Additionally thanks goes to those in South Australia who helped put this together, namely James Teale, and Mathew Jeffrey (RSSA), Andrew Dalgetty, John Gilliland, Lambertus Deluca-Lopez and Alice Fistr (PIRSA).

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 41 The declaration of exotic fish in theFisheries Unless authorised under the Fisheries Act, a (Exotic Fish, Fish Farming and Fish Diseases) person must not bring into Victoria, or take, Regulations 2000, states that, live fish of species hatch, keep, possess, sell, transport, put into any (other than those species listed in Part 1 of container or release into Victorian waterways any Schedule 2) which are non-autochthonous to aquatic species that is declared to be noxious. this state and belong to a kingdom or phylum Compliance of the above legislation is managed specified in Part 2 ofS chedule 2 are declared to and enforced by Fisheries Victoria, a division be an exotic fish. of the Department of Primary Industries (DPI). Part 1 of Schedule 2 is essentially a list Noxious aquatic species inspections currently of the ‘native fish’ of Australia, both marine and form part of station operations but are mostly freshwater, which would not be declared exotic, focussed on the ornamental sector and are unless they are a farmed fish (defined under the opportunistic. Occasionally targeted operations act). Hence any fish not listed in are planned. The Act also provides for: this list and belonging to a kingdom or • offences concerning prohibited noxious aquatic phylum specified in Part 2 ofS chedule 2 species; are declared exotic. • noxious aquatic species permits, and permit Section 51 of the Fisheries Act 1982, provides revocation; the power to make regulations for the control of • authorisation to transport, contain or release exotic fish and the control of disease in fish.T his noxious aquatic species; includes requirements that the: • notice to be given of the location of noxious • Director of Fisheries be notified of the aquatic species; occurrence of disease or symptoms of disease in aquacultured fish; • seizure and removal of noxious aquatic species; • Bringing into the State or possession or control of fish that may be affected by disease • prevention of the spread of noxious aquatic is prohibited. species; and This Section (51) also outlines that the powers of • no penalty if the noxious aquatic species fisheries officers for the detection, prevention, specimen is killed immediately. elimination or control of disease in fish, Victoria will be updating its noxious eradication or containment of exotic fish and aquatic species list in line with the recent regulation of the disposal of the water in which endorsement of a national noxious fish list in the fish have been kept are made by regulation and Strategic Approach to the Management are contained in Fisheries (Exotic Fish, Fish Farming of Ornamental Fish. and Fish Diseases) Regulations 2000. The Flora and Fauna Guarantee Act 1988 enables Compliance officers of the Department of the listing of Action Statements which define Primary Industries and Resources, South potentially threatening processes. One such Australia (PIRSA) undertake enforcement of the process has been defined as the “Deliberate regulations in South Australia. In conjunction with or accidental introduction of live fish into compliance officers, FishCare volunteers also public or private waters within a Victorian river operate in an educational role with recreational catchment in which the taxon to which the fish fishers, educating them about the various belongs cannot reliably be inferred to have been regulations and rules regarding recreational present prior to the year 1770 AD” (SAC 1992). fishing and alien fish. Action Statement No. 190 ‘Introduction of live fish into waters within Victorian river catchments’ Victoria follows the listing of that potentially threatening The Fisheries Act 1995 provides legislation process and describes the actions to be taken to for the management of noxious aquatic species. ameliorate the adverse effects of this process. Part 5, Division 2 of the Act provides for the The Guidelines for Assessing Translocations of Governor in Council, by Order in Council, to Live Aquatic Organisms in Victoria Department declare any aquatic species to be noxious, other of Primary Industries (2003), outline the risk than protected aquatic biota, protected wildlife or assessment process for planned translocations. protected flora. A Translocation Evaluation Panel (TEP, comprising representatives from the Fisheries Co-Management Council, DPI and DSE) assesses

42 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Initial Screening Applications against developed potential to introduce diseases. A list of species protocols. Proponents may be required to submit that cannot be imported without a specific full Risk Assessments (proforma is available). The permit are contained on the NSW DPI website TEP advises the Secretary, DPI, of their decision (www.dpi.nsw.gov.au). and the Secretary may approve or refuse the The introduction of fish to fresh waters outside application. their natural range is listed as a Key Threatening The “Victorian Pest Management Framework” Process (KTP) under the Fisheries Management provides a planning framework to give strategic Act 1994 and requires the development of a direction to species strategies and Action Plans. threat abatement plan. Predation by gambusia The Framework is intended to cover aquatic fauna is also listed as a KTP under the Threatened as well as terrestrial species. It is anticipated that Species Conservation Act 1995 because of its new strategies for aquatic fauna will be developed impacts on threatened frogs, and is covered by from the Framework. an approved threat abatement plan. A Hatchery Quality Assurance Program has New South Wales been developed in NSW to limit the chances The management of noxious fish inNS W is of translocation of non-target species through through the Fisheries Management Act 1994. aquaculture stocking. Enforcement is conducted by compliance officers operating on the authority of the Fisheries Australian Capital Territory Management Act 1994, with penalties of up to The Fisheries Act 2000 prohibits the release $11,000 for possession or sale of noxious fish. of live fish into public waters without written There are three classes of noxious fish under the approval of the Conservator of Wildlife. The Fisheries Management Act 1994 representing the Nature Conservation Act 1980 also prohibits the different levels of threat they pose to the aquatic release of live fish into waters in theT erritory. environment. Classifications range from Class The ACT has declared the original list proposed 1 (possession and sale banned and have the by the ‘Strategic Approach to the Management capacity to order destruction), through to Class 3 of Ornamental Fish: consultation draft’ as ‘pest (discouragement of possession). animals’ under the Pest Plants and Animals Act Different rules apply for each class in regard to 2005. This Act also allows the declaration of the possession or sale of these species. Noxious pest animals as either ‘notifiable pest animals’ listing provides NSW Department of Primary (where the presence of a pest animal must be Industries (Fisheries) with the power to seize notified to the chief executive) or ‘prohibited pest and destroy the noxious species, or require their animals’ (where the supply or keeping of the destruction, under certain circumstances or for animal is prohibited). certain classes of species. The majority of the pest fish currently listed Listed noxious fish include threeT ilapia species under the Pest Plants and Animals Act 2005 are (Class 1), plague minnow (Class 1 outside the listed as prohibited pest animals. Of the three greater Sydney region) and Carp (Class 3). The species which form the focus of this workshop, ‘Strategic Approach to the Management of Oriental weatherloach is not listed as either a Ornamental Fish’ (Bureau Of Resource Sciences, prohibited pest animal or notifiable pest animal 2005). recommends an expanded list of noxious (as they are still kept by aquarium hobbyists), fish, which will be adopted byNS W once this has Tilapia is listed as a prohibited pest animal, been endorsed. and Redfin perch is not listed as a pest animal Under recent changes to the Fisheries in the ACT. Management Act 1994 and Regulations, it is now The Pest Plants and Animals Act 2005 contains illegal to import any live noxious fish (or certain provisions for the preparation of a pest animal other aquarium, aquaculture and pest species) management plan for a pest species, but a plan into NSW without a permit. is not mandatory. A pest animal management Most species of aquarium fish can be legally plan may outline requirements for the following, imported into NSW from other States without a having regard to the potential threat and the specific permit, however, certain live fish cannot practicality of control measures: be brought into NSW without a specific permit • managing the environmental and agricultural from the Minister for Fisheries. These fish pose a impact of a pest animal in a cost effective way threat to the aquatic environment and/or have the if its eradication is impractical;

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 43 • controlling potential sources of invasion Queensland through trade, transport and escape from The Fisheries Act 1994 and the Fisheries urban areas. (Freshwater) Management Plan 1999 controls the The Fisheries Act 2000 also has provision for the management of noxious fish. declaration of noxious fish, but to date, none have Possessing, rearing, selling or buying noxious been declared. fishes is unlawful without a permit. A person It is an offence to commercially supply a who takes or possesses noxious fish is required prohibited pest animal, and is also an offence to to immediately destroy the fish and notify an recklessly supply a prohibited pest animal (e.g inspector of the destruction within two business as a contaminant of something else). It is also days of taking or first possessing them; or an offence to keep a prohibited pest animal, or to immediately give the fisheries resources to an recklessly dispose of one inspector; or immediately notify an inspector of Section 79 of the Fisheries Act 2000 prohibits, taking or possessing noxious fish. without reasonable excuse, release of a live fish Similar provisions also exist for non-indigenous into public waters (unless the fish was taken from fish (i.e. alien species that are not classified as the part of the public waters into which it noxious) unless they are listed under Schedule 6 is released). of the Fisheries Regulation 1995. Section 49 of the Nature Conservation Act 1980 The Department of Primary Industries and prohibits the release of an animal that is not Fisheries has Boating Patrol officers based at a native animal from captivity if the release Wondai and Roma to enforce inland fisheries threatens the survival, abundance or evolution of regulations. Boating Patrol officers based in any species of native animals. coastal centres also undertake a percentage of Enforcement capacity under both legislation is their duties in freshwater. largely the responsibility of park rangers. Fines of up to $150,000 can be imposed on anyone having noxious fish in their possession without a permit or persons convicted of releasing non-indigenous species. Additional penalties may be imposed to cover the cost of eradication measures.

44 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 otenone as a as R otenone Other Fisheries Fisheries Act M anagement replace will 2007 Act present ew pest animal pest N ew plans management developed be to Pest the under Animals & Plants 2005 Act apid response response R apid trialled being methodology and Pest revised. Operational Fish being S trategy updated Control activities activities Control populations new for U nknown U nknown U nknown inimal activity M inimal but presently, with change may animal pest new plans management apid response R apid C is is C R R are nvasive I nvasive es, depending on depending es, pot eradication or eradication S pot new of containment infestations U nknown T he C Animals for this addressing states all On a case by case case by case a On basis. n place I n Y location C is is C R nvasive I nvasive Detection Detection new for programs infestations o formal program formal N o T he C Animals for this addressing states all o formal program formal N o o formal formal N o but program, monitoring regular to likely programs detect onitoring ‘hot M onitoring spots’

nfo I nfo nfo on I nfo egulations are expected to be in effect in 2008. in effect in be to expected are R egulations Education Education extension / related activities species alien to management ome in place place in S ome http:// website- eg. www.pir.sa.gov.au ome in place place in S ome http:// website- eg. www.dpi.vic.gov. au/DP I / ome in place place in S ome & ‘Fishnotes’, eg. http:// - website www.fisheries.nsw. gov.au/ o formal formal N o but program, activities hoc ad conducted. http:// website: on www.environment. act.gov.au n place. place. I n http://www. web dpi.qld.gov.au ictoria, new new V ictoria, I n urray-Darling Basin jurisdictions Basin M urray-Darling Enforcement Fisheries Act 1982 Act Fisheries Fisheries Act 1995 1995 Act Fisheries NSW Fisheries NSW Act Management 1994 Nature Conservation Nature 1980; Act 2000; Act Fisheries & Plants Pest 2005 Act Animals Fisheries Act 1994 Act Fisheries R elease Fisheries Act 1982 Act Fisheries Fisheries Act 1995 1995 Act Fisheries NSW Fisheries NSW Act Management 1994 Nature Conservation Nature 1980; Act 2000; Act Fisheries & Plants Pest 2005 Act Animals Fisheries Act 1994 Act Fisheries L egislation Possession Fisheries Act 1982 Act Fisheries Fisheries Act 1995 Act Fisheries NSW Fisheries NSW Act Management 1994 Fisheries Act 2000; Act Fisheries & Plants Pest 2005 Act Animals Fisheries Act 1994 Act Fisheries C is presently addressing the development of control actions for new populations. Additionally, a permit is presently being sought regarding use of use regarding sought being presently is permit a Additionally, populations. new for actions control of development the addressing presently is C R Animals I nvasive ummary of alien fish management (control) mechanisms in mechanisms (control) management fish alien of S ummary outh Wales S outh T he tate erritory able 1: able S outh Australia S outh V ictoria ew N ew Australian Capital Capital Australian T Queensland T limited response to new infestations similar to the Queensland model. Queensland the to similar infestations new to response limited N B:

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 45 Terminology in alien species management There is a range of terms used in each State to describe non-indigenous or alien species throughout the jurisdictions examined. The table below summarises the uses of different terms in each jurisdiction.

Table 2: The terms used in each jurisdiction to describe alien species

South Victoria New South Australian Queensland Australia Wales Capital Territory Exotic (Used in Action Statement for ‘Introduction of exotic organisms into Victorian marine waters’) Noxious Alien Pest animals Used for terrestrial species (including in “Victorian Pest Management Framework”) Invasive Species Introduced species, which have contributed to the decline of native species

NB: Under the recent Fisheries Management Act 2007, the term ‘noxious’ is adopted by SA, replacing the term ‘exotic’.

Table 3: Definition of the terms used in each jurisdiction to describe alien species

Term State Definition Exotic fish South Australia Live fish of species (other than species listed in Part 1 ofS chedule 2) that are non-autochthonous to this state and belong to a kingdom or phylum specified in Part 2 of Schedule 2 are declared to be an exotic fish(Fisheries (Exotic Fish, Fish Farming and Fish Diseases) Regulations 2000) Noxious fish Queensland Noxious fish means a fish declared to be noxious in the FisheriesR egulations 1995 Exotic pest fish Queensland Fish species that are not native (indigenous) to an area Noxious fish New South Wales Noxious fish means fish declared under Division 6 of Part 7 to be noxious fish (Fisheries Management Act 1994) Noxious ACT A species of fish declared to be noxious under section 14 of theFisheries Act 2000 Pest animal ACT An animal declared to be a pest animal under section 16 of the Pest Plants and Animals Act 2005 Noxious aquatic Victoria A noxious aquatic species declared under Section 75. The Governor in Council species may declare any aquatic species to be noxious, but may not list protected aquatic biota, protected wildlife, notable wildlife or endangered wildlife under the Wildlife Act 1975, or a taxon or community listed under the Flora and Fauna Guarantee Act 1988

46 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 • Attendance and presentations at open days, Education / extension seminars, working groups; activities related to alien • Dissemination of pamphlets/brochures, such species management as “Don’t Dump That Fish”, “Aquatic Pests in NSW”, pest identification cards (marine only), and species specific brochures; and South Australia • Media releases. Information regarding the legislation that applies to existing populations of alien species is NSW plans to publicise its revised noxious aquatic provided via species list in conjunction with the promotion of the new national ornamental fish strategy.NS W • Distribution of printed material; is preparing a poster on Redfin perch (targeting • A sign posting program; recreational fishers), which will be distributed to • The FishCare Volunteer Program; and bait and tackle shops and other relevant outlets. • The PIRSA web site (www.pir.sa.gov.au). Australian Capital Territory At various field days, fishing competitions and The ACT has previously distributed the “Stop other relevant events across the state, the MDBC before you release that aquarium fish” brochure, NFS Coordinator and FishCare volunteers and will distribute any communication products distribute PIRSA and MDBC NFS printed arising from the National Ornamental Fish Policy material. Awareness of alien (new, potential and Working Group. existing) species and the impact of them is the main aim of these activities, while also providing Promotion is undertaken to fishing clubs on the insights into alien fish behaviour obtained from ban on using live bait. The dangers of discarding SA and interstate research. live bait and the potential for the establishment of feral populations (e.g. Oriental weatherloach) are Victoria also highlighted. Education activities in Victoria include the The importance of some dams as barriers to development of communication material related fish invasions (they prevent spread of Brown to recently declared noxious aquatic species trout, Carp and Redfin perch into some sub- and measures to mitigate the risk of species catchments) is highlighted to the local water spreading (eg. Victorian DSE’s “Keep your boat authority, so that these considerations can be clean” campaign). incorporated into their forward planning. The Victoria plans to publicise its revised noxious potential for inter-basin transfers to spread aquatic species list in conjunction with the aliens has been similarly highlighted, and promotion of the new DAFF Strategy. In embraced. Any such proposals would now be addition, Victoria has established an Ornamental conditional on the use of screens and other Consultative Committee. This Committee preventative equipment. provides advice in regards to communication and enforcement planning, as well as proposing Queensland aquatic species for listing as noxious. Since 2000, Queensland has operated under the “Control of Exotic Pest Fishes, An Operational For topical issues, Fisheries Notes are prepared Strategy for Queensland Freshwaters 2000- by DPI and disseminated to the relevant 2005”. The primary focus is on education given stakeholders and placed on the DPI Website. that human-assisted dispersal is a major cause At a range of field days and other events across of new introductions (see Lintermans 2004). the State, MDBC publications on noxious and alien species including Carp are distributed Recent new infestations have caused a rethink and discussed, and a model of a Williams Carp of the effectiveness of the education program. Separation Cage demonstrated. As a result, a new-targeted campaign has been launched in North Queensland. This will be New South Wales followed up in South East Queensland later in the There is extensive information on the Fisheries program. This education program also focuses on section of the DPI website. Other activities correct identification of pest fish with brochures undertaken include: and wallet sized identification cards.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 47 Additionally, the Freshwater Fisheries Unit has yabbies as bait (dead or alive) is prohibited provided the Boating Patrol with identification outside their natural environment or range. manuals for noxious fish and with a policy This is to prevent species from becoming procedure document together with relevant established in foreign habitats and causing books (e.g. Axelrod et al. 1975). environmental damage. Currently three species can be used as live Regulation and use bait, they are: • Redclaw crayfish(Cherax quadricarinatus) of Live Bait - native to the Gulf of Carpentaria Drainage Division and some river basins in the far South Australia northern portion of the East Coast Drainage The use of live bait is not directly legislated Division. Redclaw can be used as bait only against in South Australia (provided the species in these areas does not have a minimum legal size), however • Shrimp (Macrobrachium australiensis) - under Section 50 of the Fisheries Act 1982, alien found throughout Queensland and can be fish cannot be released into the natural waters used as bait in all areas of the state and hence cannot be used as live bait. • Yabby (Blueclaw crayfish)(Cherax destructor) - found naturally in the Murray- Victoria Darling, Lake Eyre and Bulloo-Bancannia The Fisheries Act 1995 prohibits the use of live Drainage Divisions, and some river basins noxious fish (as defined inS chedule 75 of the in the East Coast Drainage Division. Yabbies Act) as bait. It is an offence to use live fish as can be used as bait only in these areas. bait in Seven Creeks and certain tributaries. Presently, this issue is addressed indirectly via the prohibition of holding undersize fish. Detection programs for Stocking of fish into any water is managed via new infestations Permit and translocation approvals.

New South Wales South Australia Presently South Australia has no formal The Fisheries Management Act 1994 prohibits the detection network for freshwater species release of live fish into any waters (ie. the sea, a beyond the network of FishCare volunteers. river, creek or other naturally flowing stream of The public can report sightings via a toll free water or a lake) without a specific permit from 1800 number and publications are distributed the Minister or under an aquaculture permit. It that request people notify FishWatch if an does not apply to the immediate return of fish to unusual fish is caught.S everal incursions have waters from which they were taken. been identified to date, most notablyCaulerpa The Fisheries Management (General) Regulation in West Lakes/Port River. 2002 prohibits the use of live fish for bait in The NRM Boards in SA also have ongoing inland waters. monitoring programs for terrestrial and Australian Capital Territory aquatic pests, while extensive bio-surveys, focussed mostly on terrestrial species, are The Nature Conservation Act 1980 prohibits the also being undertaken throughout the state to release of live fish into public waters without identify present incursions and extent. written approval of the Conservator of Wildlife. The Fisheries Act 2000 also prohibits the use of Victoria live finfish as bait and prohibits the possession Extensive and ongoing faunal surveys and of live fin fish for use as bait while beside public river audits assist in monitoring existing waters. distributions, and detection of new incursions Queensland and range expansions. In Queensland live bait can be used but only within the natural distribution of the species being used. The use of fish and crustaceans such as spangled perch, redclaw crayfish, shrimp and

48 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 New South Wales Queensland Extensive and ongoing faunal surveys and river Queensland has refocussed its activities to give audits assist in monitoring existing distributions, priority to “vulnerable catchments” and “hot and detection of new incursions and range spots” within those catchments. The concept is expansions (eg. discovery of Redfin perch in the to increase the chances of early detection of upper Lachlan by NSW DPI researchers). any infestations. Surveillance by both a The public can report pest sightings to the community network and by a Fisheries Aquatic Pest Taskforce through the Protected, team provide information. Threatened and Pest Species Reporting Hotline, via email, or by post. Liaison with organisations such as Australia New Guinea Fishes Association (ANGFA), other research institutions, and other government departments has resulted in reporting of several new incursions (Jack Dempsey cichlids and white cloud mountain minnows reported by ANGFA, One-spot livebearers reported by Australian Museum, new Caulerpa outbreaks reported by university students).

Australian Capital Territory There are a series of monitoring programs (ranging from annual to triennial) that aim to detect new populations or expansion of existing populations. There is no formal pest fish reporting mechanism for members of the public. The effectiveness of the fish monitoring programs in the ACT is problematic as only a relatively small number of sites are monitored, and monitoring is relatively infrequent. Such programs will detect new incursions or range expansions, but probably only after they have become significantly established, unless by chance, species were discarded or introduced at one of the regular monitoring sites.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 49 Spot eradication or containment of new infestations

Table 4: Control method for management of pest infestations

Containment Rotenone Other South Australia Netting, electrofishing, Prior to 2000 – not Exclusion of activities and barriers, exclusion devices currently permitted control of entry into affected areas Victoria Netting, electrofishing, Nil permitted barriers, exclusion devices New South Wales Public Education, Biological Approval to use rotenone Explosives have been used Control, Translocation Policy granted from Australian in limited cases Pesticides & Veterinary Medicine Authority for eradication Australian Capital Territory Targeted education Used prior to ~2000, not Lime has been used for spot programs, ban on using live currently used eradications in small finfish as bait, farm dams Queensland Exclusion devices (eg. Restricted permit to use Physical removal by screens installed on rotenone in small isolated electrofishing or netting water outlets) waterbodies less than 2 hectares and no deeper than 2 metres

South Australia commercial fishers to remove Carp via netting Present eradication procedures in South Australia and electrofishing for commercial purposes. are focussed around containment and physical removal due to the inability to use rotenone New South Wales following national restrictions. It is expected that Eradications have been attempted on fish the granting of a national licence will permit use contained in small closed systems (eg. Jack of rotenone in a small number of circumstances Dempsey cichlids in disused quarry, One-spot where it is an enclosed waterbody or very small in livebearers in golf course ponds), and new nature and no threatened species exist. infestations of Caulerpa. Present controls focus on excluding various Eradication of new infestations is hampered by fishing and boating activities such as anchoring the lack of specific surveillance and reporting from areas and restricting public entry following programs (to detect new pest species at an identification of alien plants, while new early stage) and the lack of agreed and tested infestations of fish are controlled using physical emergency response arrangements for inland removal such as electrofishing and netting in waters (it is understood these are arrangements conjunction with regular and ongoing monitoring. are under development as part of a project by the Invasive Animals CRC). In reality, new Victoria infestations tend to be either in confined Rotenone is not available for use, unless approved waterbodies, reducing necessity for emergency by the Minister. response, or already too widespread for realistic eradication. It is an offence to return noxious fish to the wild and hence recreational anglers catching noxious NSW has successfully applied to the APVMA, on fish cannot return them to waterways. behalf of all jurisdictions (excluding Victoria) for a national permit to use rotenone for pest Persons can apply for Noxious Aquatic Species fish control. Permits to spot eradicate species such as Carp from private waters. Advice is also provided to landholders on eradication methods, including via the website and publications such as ‘Fish in Farm Dams’. Permits have been issued to

50 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Australian Capital Territory Control activities for The ability to act quickly to eradicate outbreaks is hampered by the current inability to use rotenone established populations (not registered in the ACT). The current national The states are involved in the Invasive Animals registration process will improve the capacity of CRC which is developing a series of new the ACT to deal quickly with new infestations. control techniques like ‘Daughterless Carp‘ Rotenone has been used successfully in the for application to invasive fish such as Carp past to eliminate small populations or localised and other species. Each jurisdiction also has a occurrences of alien species such as Carp in farm range of activities that it presently undertakes dams, Eastern gambusia in ponds, trout from to control established populations, from small sections of stream above a barrier etc (See commercial fishing to recreational fishing Lintermans 2000). competitions that target alien species to However the inability to respond quickly in the spot eradications. past to newly detected invasions has resulted in the establishment of Redfin perch in 1983 South Australia (Lintermans et al. 1990), and the establishment of Alien fish of theR iver Murray are the only new population of weatherloach in 1990. In both population presently being targeted with control cases, the delays were the result of protracted activities, specifically a feral based commercial intra-departmental negotiations about whether operation. In addition, it is an offence to return and how to proceed. alien fish to the wild and hence recreational anglers catching alien fish cannot return them Slaked lime has also been used to eradicate Carp to the waterways. Additionally Carp fishing from farm dams in the Canberra region. competitions also target local abundances Queensland of Carp and other alien species with several significant catches in recent years. Fisheries are developing a rapid response approach, however their ability to act is limited by Victoria available eradication tools. Rotenone is not available for use, unless At present, Fisheries has a restricted permit to approved by the Minister. use rotenone in small isolated waterbodies less Persons can apply for Noxious Aquatic Species than 2 hectares and no deeper than 2 metres. Permits to spot eradicate species such as Carp Eradications have been carried out in small dams from private waters. Advice is also provided to but the permit is often too restrictive for many landholders on eradication methods, including situations. Fisheries are working with other via the website and publications such as ‘Fish states to get a less restrictive permit. in Farm Dams’. Permits have been issued to Fisheries have developed an Operational Manual commercial fishers to remove Carp via netting for the use of rotenone. Eighteen staff have and electrofishing for commercial purposes. been trained and a store of rotenone is available In addition to these activities, Victoria originated together with dispersal and safety equipment. the idea of Carp (Williams) separation cages and Through a regional planning process, Queensland researchers from the Arthur Rylah Institute are have undertaken a number of containment working to improve this design for adoption at all activities. An example is screens that have been fishways being constructed as a part of theS ea installed on water off-takes from Boondooma to Hume Dam fishway program. Dam in south-eastern Queensland and from Tinaroo Dam in north Queensland. In both cases, New South Wales the screens have been installed to prevent Few ongoing control activities, apart from the spread of Tilapia (at considerable expense involvement in research such as the ‘Daughterless to the infrastructure owners). In the case of Carp’ project. For an eradication of Jack Dempsey Tinaroo dam, the screens are protecting the Gulf cichlids, progressively larger blasts of explosives Catchments from possible Tilapia infestations. were used while multiple rotenone treatments of One-spot livebearers were required to eradicate that population.Advice and contacts are regularly provided to councils, businesses and public landholders on eradication methods.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 51 Australian Capital Territory removal or the use of explosives should be Through education activities largely targeted at further developed for immediate use prior to anglers, spot eradications from farm dams, and approval for rotenone. low-level surveillance and monitoring activities, As a part of this, an assessment of the suitability two catchments (Cotter River upstream of Cotter of rotenone for use in all aquatic environments, Dam; Queanbeyan River upstream of Googong including rivers, should be undertaken to reservoir) are free of Carp and one catchment demonstrate the benefits and limitations of (Cotter River upstream of Cotter Dam) is Redfin this technique and spur on the development perch free. The importance of the barrier posed and investigation of other novel methods for by water supply dams to upstream colonisation by eradication. Further the development of an alien species has also been emphasised in liaison alien species response framework for the activities with local water and land management Murray-Darling Basin that can be adopted by agencies. Such barriers have prevented the all jurisdictions is required, thus forming the upstream establishment of Carp, Redfin perch, cornerstone of a coordinated response strategy. and Brown trout in the Cotter River system. One other obvious necessity that would be part of the response strategy is improved investment Queensland in education and awareness for all jurisdictions. Queensland has few ongoing control activities. While significant work is undertaken in this The South East Queensland Carpbusters initiative area and information is distributed, infestations aimed to improve the riverine environment of are still occurring throughout the Basin the Logan and Albert River systems through that could be reduced or prevented through reducing the numbers of Carp and restocking improved awareness. Queensland has adopted with native fingerlings is starting in the Basin. a ‘catchment at risk’ methodology, to identify Forest Lakes near Brisbane is regularly netted areas for investment of limited resources. This to reduce Tilapia numbers and may serve as an approach is most likely to minimise the likelihood experimental site for other techniques. of Tilapia accessing waters of the Murray-Darling Queensland will use the results of vulnerability Basin and spreading through it in a manner analysis research on Carp and Tilapia to similar to that of Carp in the 1960’s. determine if targeted control measures are Improvement is required in regulation of aspects possible elsewhere. of the hobby/aquarium industry especially with regard to licensing non-permitted species already present in Australia and management of Summary Koi carp and other similar species. Appropriate In summarising the information contained arrangements are being proposed in Bureau Of it is apparent that legislation relating to the Rural Sciences (2005) that will partly address this management of alien species exists in each issue but states will be required to enforce any jurisdiction. However, the major deficiency in new licensing arrangements. The black and grey alien species management across jurisdictions, list produced by this group should be adopted not withstanding differences in terminology, by all jurisdictions as the minimum listing of is in the policy area. Specifically, responses of alien species not permitted unless granted with the jurisdictions to new infestations and control exemptions and licences to regulate of existing populations with limited scope for these species. activities that will impact on populations once Finally, all jurisdictions should seek to adopt established – the lesson here is a need for uniform classification and regulations for alien ongoing, intensive and rigorous monitoring species (potentially to align with South Australia’s and control of populations as soon as they are new Fisheries Management Act 2007), this will detected to minimise impacts and increase the finally be the case with all jurisdictions now using likelihood of eradication. the word ‘noxious’ to describe unwanted alien As a priority, approval must be sought for use of species – the remaining challenge for managers rotenone to undertake spot eradication of new in this respect is how the ‘desirable’ alien species infestations in all jurisdictions, with sensible (eg. Redfin perch and trout) are managed. restrictions and appropriate training in safe Another challenge is human-assisted dispersal. handling of this chemical. In addition, other The majority of new infestations or extensions techniques already available such as physical to range that have occurred in Australia are as a

52 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 result of humans physically transporting them SAC 1992 Final recommendation on a nomination to new waterbodies. Improving the regulation for listing: ‘Deliberate or accidental introduction and enforcement of human assisted dispersal of live fish into public or private waters within a Victorian river catchment in which the taxon to (ie. use of fish as live bait across jurisdictions) in which the fish belongs cannot reliably be inferred conjunction with improved awareness will assist to have been present prior to the year 1770 AD’ with this issue. (potentially threatening process) (Nomination No. Alien species pose a significant challenge to 204). Scientific Advisory Committee, Flora and all levels, including managers, scientists and Fauna Guarantee. Department of Conservation and Natural Resources. Melbourne. the community. Whilst legislative frameworks for the management of alien species exist in each jurisdiction, further work is needed on the development and implementation of effective policies.

Bibliography Axelrod, H.R., Burgess, W.E., Pronek, N. & Walls, and J.G. 1997 Dr Axelrod’s atlas of freshwater aquarium fishes 9th edition .T .F.H. Publications, U.S.A. Bureau of Rural Sciences 2005. A Strategic Approach to the Management of Ornamental Fish in Australia - Consultation Draft. Marine and Coastal Committee Natural Resource Management Standing Committee. Canberra 38pp Department of Natural Resources and Environment. 2002. Victorian Pest Management: A Framework for Action. Department of Primary Industries (2003). Guidelines for the translocation of live aquatic organisms in Victoria. Completed by the Victorian Aquatic Organisms Translocation Guidelines Steering Committee. Department of Primary Industries & Department of Sustainability and Environment. Melbourne Victoria 24pp Lintermans, M. 2000. Recolonisation by the mountain galaxias Galaxias olidus of a montane stream after the eradication of rainbow trout Oncorhynchus mykiss. Marine and Freshwater Research 51: 799-804. Lintermans, M. 2004. Human-assisted dispersal of alien freshwater fish in Australia.New Zealand Journal of Marine and Freshwater Research 38: 481–501. Lintermans, M., Rutzou, T. and Kukolic, K. 1990. Introduced fish of the Canberra region - recent range expansions. In: D. Pollard (ed.), Australian Society for Fish Biology Workshop: Introduced and Translocated fishes and their Ecological Effects. Bureau of Rural Resources Proceedings No. 8, Australian Government Publishing Service, Canberra. Pp. 50–60.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 53 Managing pest fish in the Murray-Darling Basin: lessons learnt from previous invaders

John Koehn Arthur Rylah Institute for Environmental Research, 123 Brown Street, Heidelberg VIC 3084.

Abstract Why care? Pest freshwater fish species are an increasing Introduction of alien species is considered a threat across both the Murray-Darling Basin greater threat to the biodiversity of freshwater and Australia. The invasion of carp Cyprinus ecosystems because of the intentional and carpio illustrates how quickly an introduced unintentional release of organisms (Sala et al. fish species can spread and dominate fish 2000). Australia has five of the world’s eight most communities. Carp are the highest profile invasive fish taxa as listed by theI nternational aquatic invader and have received the most Union for the Conservation of Nature (Lowe attention, hence, provide an ideal case study et al. 2000): Brown trout Salmo trutta, Carp from which to learn lessons for alien species Cyprinus carpio, Mozambique tilapia Oreochromis management. The need for risk assessments to mossambicus, Rainbow trout Oncorhynchus predict future impact of species is highlighted mykiss, and Gambusia Gambusia affinis/holbrooki. and the adaptation and application of existing Four of these species occur in the Murray-Darling policy and management documents that have Basin with the fifth T( ilapia) under consideration been produced for carp should readily assist the at this workshop as the risk of its entry into management of other species. the Murray-Darling Basin is considered to be high. Australia has a relatively depauperate freshwater fish fauna by world standards Introduction (slightly over 300 species; Allen et al. 2002). More The number of alien freshwater fish species than 16% of these are considered to be under in Australia, their abundance, and distribution conservation threat nationally (Crook 2001) and are all continuing to steadily increase (Koehn detrimental interactions with alien species are and Mackenzie 2004). There are now 43 alien considered a threat to 77% of these species fish species that have been introduced into (Jackson et al. 1993). Australia, with at least 22 species having become established (Koehn and Mackenzie 2004). This total number of fish species is Invasive species comparable to the number of established alien There are several attributes that have been mammals (25), birds (20) amphibians (1) and identified as important attributes of successful reptiles (4) combined (Bomford 2001). Seventy invasive species (Ricciardi and Rasmussen 1998). four percent of fish species were introduced These attributes include: wide distributions, wide for ornamental reasons, 21 % for recreational environmental tolerances, high genetic variability, angling and 5 % for other reasons such as short generation times, rapid growth, broad diet, biological control. Eleven of these alien species early sexual maturity, high reproductive capacity, are now established in the Murray-Darling gregariousness, natural dispersal mechanisms Basin (from Koehn and Mackenzie 2004). and are connected with human activity. There is a need for risk assessments to be undertaken for alien species with a predictive capacity to determine potential future impacts.

54 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 These can be undertaken against the criteria effective management strategy (see Koehn et outlined above after collating information on the al. 2000). Carp have become the most abundant following areas: large freshwater fish in southeast Australia, • Invasion history; now distributed over more than 1 million km2 (Koehn et al. 2000; Lintermans 2002). Carp were • Biological information; introduced into Australia several times from • Environmental information; the mid- 1800’s but their widespread dispersal • Identify donors/dispersal pathways; and only occurred following the introduction of • Human activity. the ‘Boolara’ strain in Victoria in the 1960s. Introduction dates for each State are as follows A range of detailed reviews have been (‘Boolara’ strain dates underlined) (Koehn et al. undertaken for some species within the Murray- 2000): Victoria- 1859, 1960; NSW -1860s, 1970s; Darling Basin (see Clunie et al. 2002, Koehn and ACT 1976; SA -1960, 1970s; Tas -1974, 1980, Mackenzie 2004). Using this existing knowledge 1995; Qld -1960, 1970s. A recent invasion into an assessment was undertaken to determine the Glenelg River catchment has expanded their which of the existing established and abundant western distribution in Victoria. alien species could provide the best lessons for pest fish species management.T he most Progressive steps of carp expansion in Australia widespread species, Gambusia has received can be summarised as: minimal attention and, in many ways, has been 1. Aquaculture production; considered too hard to address as a threat. 2. Stocking into farm dams; Trout (Brown and Rainbow) are restricted 3. Introduction into the Murray River; largely only to upland areas and continue to be stocked for recreational fisheries.G oldfish 4. Expansion throughout Murray-Darling Basin Carassius auratus, Roach Rutilus rutilus and assisted by flooding; and Tench Tinca tinca have all received minimal 5. Transfers to other catchments either; a) as attention and there is little information about bait by anglers, or b) transferred by anglers to their impacts. There is, however, a considerable establish new coarse fisheries. volume of literature and attention that has been focussed on carp. Carp are the largest and most visible introduced Risk analysis fish species in Australia and have a high public There are few detailed species-specific risk profile.T hey have been subject to considerable assessments (e.g. Barlow and Lisle 1987; scientific study and review, both in Australia Townsend and Winterbourn 1992) that predict the and overseas (Hume et al. 1983; Koehn et future impacts of already established introduced al. 2000). Carp have been the subject of a fish species (Arthington and Bluhdorn 1995; series of national workshops (Murray-Darling Coates and Ulaiwi 1995; Clunie et al. 2002). A Association Inc 1995; Murrumbidgee Catchment retrospective risk assessment was undertaken Management Committee 1994; Lapidge 2003), a to examine the reasons for the successful National Strategy and various policy, research invasion of carp and to make predictions about and control documents (Braysher and Barrett future range expansion and potential impacts 2000; Carp Control Coordinating Group 2000a, (Koehn 2004). This included: assessment of 2000b), and have received considerable public the attributes associated with successful alien and political attention, including the formation invasive species (see above); the documented of a National Carp and Pest Fish Taskforce history of spread; consideration of ecosystems (Murray-Darling Association Inc. 2003). Carp and communities; environmental condition and were therefore considered the best species trends; limiting factors and dispersal pathways. from which to learn lessons and also provide An ecological comparison was made between an example framework for the management of carp and native species to gain a perspective on other alien species. ‘ecological closeness’ which included: maximum The invasion of carp in the Murray-Darling size; depth position; behaviour; diet; feeding; Basin illustrates how quickly an introduced fecundity; environmental tolerances; habitat fish species can spread and dominate fish specificity; habitat range; movement; dispersal; communities (in numbers and biomass) in growth; physical toughness; adaptability and the absence of early intervention and an competitiveness. Climatic comparisons were made to assess the likely climactic range

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 55 that carp could occupy within Australia. This 2004). This review identified a lack of recognition approach could be used as a basis to assess all of the problem, inconsistency in legislation, alien species within the Murray-Darling Basin, policy, and approaches across jurisdictions including those considered in this workshop. and no nationally coordinated on-ground In summary, carp were found to have most of management actions. Where legislation and the attributes of successful invasive species, policy was available it was not always used to were ecologically different to most native good effect. The National Management Strategy species across a range of different native for Carp Control (NMSCC) and other documents fish communities, and had expanded rapidly provide a strong framework from which to base in areas such as the Murray-Darling Basin management of this and other alien species. where habitats had already been degraded and To be of any use, however, these documents populations of major native fish predators had must be used and the appropriate policies and been greatly reduced. Carp had few climatic management actions implemented. restrictions and were deemed capable of Several legislative framework and policy invading most freshwater systems across the documents already exist in Victoria to implement remainder of the continent. The main transfer better pest fish management. For example: mechanisms between basins occurred by 1. The introduction of live fish outside their natural humans either as deliberate introductions range is listed as a Potentially Threatening or use as bait. The koi aquarium trade was Process under the Flora and Fauna Guarantee identified as a serious dispersal pathway and Act 1992 (Scientific Advisory Committee 1992), inter basin water transfers were identified as however, an Action Statement is required. another potential transfer mechanism. 2. Fish should be included in the Victorian Our knowledge of the biology and ecology of Pest Management - A Framework for Action many alien species, especially under Australian (Department of Natural Resources and conditions, is limited. Our understanding of Environment 2001). their impacts is rudimentary, even for direct 3. Documents that underpin The Victorian River impacts such as predation, let alone impacts at Health Strategy (Department of Natural the community or ecosystem levels (Townsend Resources and Environment 2002) need to 2003). An understanding of impacts is important include details of management actions for to build support for adequate alien species pest fish species. Changes in the geographic management and to provide some basis for distribution of indigenous and exotic fish benefit:cost analyses of management options species have been recommended as (Choquenot et al. 2004). Understanding impacts environmental health indicators (Office for is an essential component of best-practice the Commissioner for the Environment 1988). vertebrate pest management, which is based Fish and alien fish species have now been on the concept of managing impacts rather considered in other measures of river health than numbers (Braysher 1993). Despite the in the Sustainable Rivers Audit (Harris 1995; attention focussed on carp, their ecological Whittington et al. 2001; Murray-Darling Basin and environmental impacts are poorly defined Commission 2004). (Koehn et al. 2000) and remain mainly limited to impacts on water quality (eg. Driver et al. Although the NMSCC relates only to one species, 2005; King et al. 1997). it can easily be adapted to include other alien species, as has been done in Queensland (Department of Primary Industries, Queensland Discussion 2001), forming the basis of a national or Basin- wide alien species management plan. The Action A range of policy and management documents Plan for the Murray-Darling Basin, developed for already exist relating to alien species alien species by the National Carp and Pest Fish management in Australia. A synthesis of Taskforce, a community focussed organisation the literature (including “grey” literature), (Murray-Darling Association Inc. 2003), could identified current management frameworks for also be expanded and incorporated into a national invasive freshwater fish species, assessed the strategy. current status in terms of species knowledge and management, and suggested a new management approach with a list of priority management actions (Koehn and Mackenzie

56 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 The goal of management for alien species Lessons learnt from the is not a reduction in numbers per se, but a reduction in the impacts caused by each prior invasion of alien species (Lodge and Shrader-Frechette 2003) (e.g. predation, competition, ecosystem species in the Murray- changes). This together with the use of pest Darling Basin management principles (Braysher 1993; • Remember carp and the cane toad Bomford and Tilzey 1997) and adoption of (Koehn et al. 2000; Koehn 2004; Suthurst integrated approaches will give the best et al. 1996) results. Clearly defining the problem, the objectives and the measurables is important • Management must limit spread. before action is taken. This may require the Spread can be rapid. development of new skills and organisational • Humans are the main transfer mechanism. links that go beyond the traditional roles of • There is a need to incorporate social science fisheries agencies and current management into pest fish management. expertise. Most transfer of alien fish between • Successful and unsuccessful local eradication catchments is human assisted (Lintermans efforts should be documented and learnt from. 2004) and transfers by anglers have been Successful attempts should be promoted as recognised as a major source of invasion into educational exercises. new catchments both in Australia and New Zealand (McDowall 1997; Koehn et al. 2000). • Education, information exchange, awareness Social research and appropriate education, and a change in public thinking is needed. management and enforcement options are • Key stakeholder groups need to be engaged- required for this issue. The lack of community anglers, aquarium and water industries. education and awareness of the threats posed • Public pressure, media and political by alien fish has also been recognised.T here support is necessary. is a need for invasive species response squads • Listings and legislation help raise priorities with the appropriate funding and tools to deal and legal obligations. with new incursions. The costs of alien species both in economic and environmental terms can • Pest fish need to be included in other planning be considerable, and quantification of these regimes eg. regional planning. using bioeconomics benefit/costs analyses (see • Community engagement is imperative. Choquenot et al. 2004) is needed to reinforce • There is a need to be serious, the need for action. committed and vigilant. • Preventative programs and early actions will Tools that are needed limit impacts and be the most cost effective. There is a range of tools needed to undertake appropriate management of alien species including: • Integrated, coordinated plans, using Pest Management Principles and a national approach. • Risk assessments that are undertaken pro-actively and have predictive capacity. • Databases, surveillance and monitoring. • Plans for prevention of spread. • Response plans and squads. • Bio-economic assessments. • Research to increase biological knowledge, predictive capabilities and risk assessments. • Further development and acceptance of protocols for the use of control techniques.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 57 Coates, D. & Ulaiwi, W.K. 1995. A simple model for Acknowledgments predicting ecological impacts of introduced aquatic The author wishes to thank Ivor Stuart, Mark organisms: a case study of common carp Cyprinus carpio L., in the Sepik-Ramu river basin, Papua New Lintermans and Tim O’Brien for comments Guinea. Fisheries Management and Ecology 2: on the manuscript. 227-242. Crook, D. 2001. Threatened species supplement. Australian Society for Fish Biology Newsletter 31(2): References 37-41. Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Department of Natural Resources and Environment Guide to the Freshwater Fishes of Australia. USA, THF 2001. Victorian Pest Management - A Framework Publications Inc. for Action. Department of Natural Resources and Arthington, A.H. & Bluhdorn, D.R. 1995. Improved Environment, Victoria. management of exotic aquatic fauna: R&D for Department of Natural Resources and Environment Australian rivers. Canberra, Land & Water Resources 2002: Healthy Rivers, Healthy Communities and Development Corporation Ocassional Paper 04/95. Regional Growth. Victorian River Health Strategy. Barlow, C.J. & Lisle, A. 1987. Biology of the Nile Department of Natural Resources and Environment, Perch (Lates niloticus (Pisces: Centropomidae) with Victoria. reference to its proposed role as a sport fish in Department of Primary Industries, Queensland. 2001. Australia. Biological Conservation 39: 269-289. Control of exotic pest fishes. An operational strategy Bomford, M. 2001. Can we quantify the risk that for Queensland waters 2000-2005. Queensland, imported vertebrates could establish wild pest Department of Primary Industries. population in Australia? In: Proceedings of the 12th Driver, P.D., Closs, G.P. and Koen, T. 2005. The Australian vertebrate pest conference, Melbourne, effects of size and density of carp (Cyprinus carpio) on Victoria, 21-25 May 2001. Natural Resources and water quality in an experimental pond. Archives de Environment, Victoria. Pp. 178-183. Hydrobiologia 163: 117-131. Bomford, M. & Tilzey, R. 1997. Pest management Harris, J.H. 1995. The use of fish in ecological principles for European carp. In: Roberts. J. & assessments. Australian Journal of Ecology 20: 65-80. Tilzey R. ed. Controlling carp: exploring the options Hume, D.H., Fletcher, A.R. & Morison, A.K. 1983. for Australia. Proceedings of a workshop 22–24 Final Report. Carp Program Report No. 10. Fisheries October 1996, Albury. CSIRO & Murray–Darling Basin and Wildlife Division, Victorian Ministry for Commission. Canberra. Pp. 9–20. Conservation. Braysher, M. 1993. Managing vertebrate pests: Jackson, P.D., Koehn, J.D. & Wager, R. 1993. principles and strategies. Bureau of Resource Appendix 1: Australia’s threatened fishes 1992 listing Sciences, Australian Government Publishing Service, - Australian Society for Fish Biology. In: Hancock, Canberra. D.A. ed. Sustainable fisheries through sustaining Braysher, M. & Barrett, J. 2000. Ranking areas fish habitats. Proceedings of the AustralianS ociety for action: a guide for carp management groups. for Fish Biology Workshop, Victor Harbour, South Murray-Darling Basin Commission, Canberra. Australia, 12-13 August. Bureau of Resource Carp Control Coordinating Group 2000a. National Sciences. AGPS, Canberra. Pp. 213-227. management strategy for carp control 2000-2005. King, A.J., Robertson, A.I. & Healey M.R. (1997) Murray-Darling Basin Commission, Canberra. Experimental manipulations of the biomass of Carp Control Coordinating Group 2000b. Future introduced carp (Cyprinus carpio) in billabongs. directions for research into carp. Murray-Darling I. Impacts on water-column properties. Marine & Basin Commission, Canberra. Freshwater Research 48, 435–443. Choquenot, D., Nicol, S. & Koehn, J. 2004. Koehn, J.D. 2004. Carp (Cyprinus carpio) as a powerful Bioeconomic modelling in the development of invader in Australian waterways. Freshwater Biology invasive species policy. New Zealand Journal of Marine 49: 882-894. and Freshwater Research 38: in press. Koehn, J.D. & Mackenzie, R.F. 2004. Priority Clunie, P., Stuart, I., Jones, M., Schreiber, S., management actions for alien freshwater fish McKay, S., O’Connor, J., McLAren, D., Weiss, J., species in Australia New Zealand Journal of Marine Gunasekra, L. & Roberts, J. 2002. A risk assessment and Freshwater Research 38: 457-472. of the impacts of pest species in the riverine Koehn, J.D., Brumley, A.R. & Gehrke, P.C. 2000. environment in the Murray-Darling Basin. Report Managing the impacts of carp. Bureau of Rural produced for the Murray-Darling Basin Commission, Sciences, Canberra. Strategic investigations and Riverine Program, Lapidge, K.L. (ed.) 2003. Proceedings of the National Project R2006. Freshwater Ecology, Arthur Rylah Carp Control Workshop, March 2003, Canberra. Institute for Environmental Research, Victoria. Cooperative research Centre for Pest Animal Control, Canberra.

58 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Lintermans, M. 2002. Fish in the Upper Scientific Advisory Committee. 1992. Flora and Murrumbidgee Catchment: A Review of Current Fauna Guarantee Act final recommendation on Knowledge. Environment ACT, Canberra. a nomination for listing. Deliberate or accidental Lintermans, M. 2004. Human-assisted dispersal of introduction of live fish into public or private waters freshwater fish species in Australia: a review.New within a Victorian river catchment in which the Zealand Journal of Marine and Freshwater Research taxon to which the fish belongs cannot reliably be 38: 481-502. inferred to have been present prior to the year 1770 AD. Victoria, Department of Conservation, Forests Lodge, D.M. & Shrader-Frechette, K. 2003. and Lands. Nonindigenous species: ecological explanation, environmental ethics, and public policy. Biological Sutherst, R.W., Floyd, R.B. & Maywald, G.F. 1996. Conservation 17: 31-37. The potential geographical distribution of the cane toad, Bufo marinus L. in Australia. Conservation Lowe, S. J., Browne, M. & Boudjelas, S. 2000. 100 of Biology 10: 294-299. the world’s worst invasive alien species. IUCN/SSC Invasive Species Specialist Group (ISSG), Auckland, Townsend, C. R. 2003. Individual, population, New Zealand. community and ecossytem consequences of a fish invader in New Zealand streams. Conservation McDowall, R.M. 1997. A brief history of carp Biology 17(1): 38-47. in New Zealand. In: Roberts, J.; Tilzey, R. ed. Controlling carp: exploring the options for Australia. Townsend, C.R.& Winterbourn, M.J. 1992. Proceedings of a workshop, 22–24 October Assessment of the environmental risk posed by an 1996, Albury. CSIRO & Murray–Darling Basin exotic fish: the proposed introduction of channel Commission, Canberra. Pp. 1-9. catfish Ictalurus( punctatus) to New Zealand. Conservation Biology 6: 273-282. Murray-Darling Association, Inc. 1995. National Carp Summit Proceedings. Murray-Darling Whittington, J., Coysh, J., Davies, P., Dyer, F., Association, Adelaide. Gawne, B., Lawrence, I., Liston, P., Norris, R., Robinson, W. & Thoms, M. 2001. Development of Murray-Darling Association, Inc. 2003. Community a framework for the sustainable river audit. Draft and local government involvement in the Final Report Project R2004. Cooperative Research management of alien and pest fish in theM urray- Centre for Freshwater Ecology, Canberra. Darling Basin. An Action Plan. Murray-Darling Association, Albury. Murray-Darling Basin Commission. 2004. Fish Theme Pilot Audit Technical Report – Sustainable Rivers Audit. Murray-Darling Basin Commission, Canberra. Murrumbidgee Catchment Management Committee 1994. Proceedings of the forum on European Carp, Wagga Wagga, June 1994. Murrumbidgee Catchment Management Committee, Wagga Wagga. Office for the Commissioner for the Environment. 1988: State for the envirnoment report 1988. Victoria’s inland waters. Office for the Commissioner for the Environment, Victoria. Ricciardi, A. & Rasmussen, J.B. 1998. Predicting the identity and impact of future invaders: a priority for aquatic resource management. Canadian Journal of Fisheries & Aquatic Sciences, 55, 1759-1765. Roberts, J. & Tilzey, R. ed. 1997. Controlling carp: exploring the options for Australia. Proceedings of a workshop 22–24 October 1996, Albury. CSIRO & Murray–Darling Basin Commission, Canberra. Sala, O.E., Chapin, F.S. III, Armesto, J.J., Berlow, E., Bloomfield, J., Dirzo,R ., Huber-Sanwald, E., Huenneka, L.F., Jackson, R.B., Kinzig, A., Leemans, R., Lodge, D.M., Mooney, H.A., Oesterheld, M., Poff, N.L., Sykes, M.T., Walker, B.H., Walker, M. & Wall, D.H. 2000. Global biodiversity scenarios for the year 2010. Science 287: 1770-1774.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 59 Risk assessment modelling to identify potential fish invaders

Mary Bomford Bureau of Rural Sciences, GPO Box 858, Canberra ACT 2601.

Abstract fish species can probably establish if they are released enough times. Hence investment is Risk assessment modelling can be used to help needed in educating the community to improve determine which exotic fish species are most awareness of the consequences of releasing likely to establish pest populations in the Murray- exotic fish. Darling Basin. Five factors are correlated with the establishment success of exotic freshwater fish in Australia: (1) climate match; (2) overseas range Introduction size; (3) number of continents where the species At least 33 species of alien freshwater fish have has established exotic populations; (4) proportion successfully established exotic populations in of introduction events that have been successful Australia, including at least 14 new fish species for the species; (5) proportion of introduction that established between 1997–2006 (Tables 1 events that have been successful for species in and 2). At least another 16 species have been the same genus or family. A fish species’ scores identified in Australian water bodies but are not for these five factors can be summed to give an known to have established breeding populations establishment risk score. The number of times (Kailola 2000; Bomford and Glover 2004, Table 2). and places a species is released is also strongly Bomford and Glover (2004) developed a risk correlated with establishment success and most assessment model to predict the likelihood fish species will establish exotic populations if that exotic freshwater fish species introduced they are released often enough. Of the 33 exotic to Australia could establish wild populations. fish species known to be established in the wild The Australian Government Department of in Australia, four have high climate matches to the Environment and Heritage use the risk the whole of the Murray-Darling Basin: Carp, assessment model to help make decisions on Mozambique tilapia, Rainbow trout and the which species should be banned from import and , and a further six to large parts of the which species can be let into Australia. The States Basin: Sailfin molly, Platy,T ench, Goldfish, can also use the model for making decisions Brown trout and Roach. The risk assessment about whether to restrict trade and keeping of model predicts all ten species are highly suited exotic fish species that are already present to establishing exotic populations in the Murray- in Australia. Darling Basin. The model also predicts that many other species which have not yet Predicting whether or not an alien species could established in the wild in Australia are highly establish a wild population in Australia is always suited to establishing pest populations in the subject to uncertainty. This is partly because Murray-Darling Basin should they be released scientific knowledge on species invasions is there. Some of these species are reported to still in its early stages and no ecological models have major adverse impacts where they have are yet available that can make highly accurate established exotic populations overseas. Risk predictions for all species. Secondly, even if good assessments need to be conducted on all the models are developed, there are often inadequate exotic fish species (over 1000) that are kept and data on the distribution and ecology of individual traded in Australia so that an alert list of high- species, and these data are required to conduct risk species can be developed. However, most assessments using the models. If the input data

60 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Table 1. Numbers of exotic fish species established in Australia.

Date Number of species Source 1967 9 Weatherley and Lake (1967) 1997 19 Arthington and McKenzie (1997) 2004 31 Lintermans (2004) 2006 33 Lintermans pers. comm. (2006)*

*In 2006 the rosy barb Puntius conchonius and the pearl cichlid Geophagus brasiliensis established exotic populations in Western Australia.

Table 2. Exotic species of freshwater finfish introduced to Australia.

Successfully introduced species Unsuccessfully introduced species (recorded but not known to be established) Carp Cyprinus carpio* Sumatra barb Puntius tetrazona Tench Tinca tinca* Dominican gambusia Gambusia dominicensis GoldfishCarassius auratus* rivulatus Roach Rutilus rutilus* Firemouth cichlid Thorichtys meeki White-cloud mountain minnow Tanichthys albonubes Banded cichlid Heros severus MosquitofishGambusia holbrooki + affinis* Redhead cichlid Vieja synspila Guppy Poecilia reticulata Blue tilapia Oreochromis aureus One-spot live bearer Phalloceros caudimaculatus Wami tilapia Oreochromis urolepis Sailfin mollyPoecilia latipinna Chinook salmon Oncorhynchus tshawytscha Platy Xiphophorus maculatus Atlantic salmon Salmo salar* Green swordtail Xiphophorus hellerii Plainfin frogfishPorichthys notatus Mozambique tilapia Oreochromis mossambicus Japanese seabass Lateolabrax japonicus Red devil/Midas cichlid citrinellus Sobaity seabream Sparidentex hasta Three-spot cichlid trimaculatum Common triplefinForsterygion lapillum Victoria Burton’s haplochromine Haplochromis burtoni Redbanded perch Hypoplectrodes huntii Niger cichlid Tilapia mariae American flagfishJordanella floridae Oscar Astronotus ocellatus Blue acara Aequidens pulcher Archocentrus nigrofasciatus Jewel cichlid Hemichromis bimaculatus Redbelly tilapia Tilapia zillii Jack Dempsey Cichlasoma octofasciatum Oriental weatherloach Misgurnus anguillicaudatus* Redfin perchPerca fluviatilis* Rainbow trout Oncorhynchus mykiss* Brown trout Salmo trutta* Brook trout Salvelinus fontinalis* Three-spot gourami Trichogaster trichopterus Yellowfin gobyAcanthogobius flavimanus Goby Acentrogobius pflaumii Chameleon goby Tridentiger trigonocephalus Rosy barb Puntius conchonius Pearl cichlid Geophagus brasiliensis

* denotes species recorded in the Murray-Darling Basin.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 61 are unreliable or incomplete, the models will give 2. Overseas range size less reliable results. Some ecologists doubt that This was calculated as the number of 1 degree it is possible to build accurate models to predict latitude by one degree longitude grid cells in the outcomes of exotic finfish introductions which the fish was recorded as present (either in because there has been so little progress in its natural or exotic range, excluding Australia) in developing generalisations about the factors http://www.fishbase.org. affecting the establishment and impacts of introduced species (Ricciardi and Rasmussen 3. Exotic elsewhere 1998; Williamson 1999). Some ecologists consider A score calculated from the number of continents the consequences of an introduction are largely on which an exotic population of the fish has dependent on individual circumstances (such established. as timing, biotic and abiotic components of the invaded habitat, and numbers and condition of 4. Introduction success rate for species introduced fish) and on stochastic events, all of which can make outcomes highly unpredictable. Arthington et al. (1999) recorded the number of Other ecologists believe that simple models, introduction events and the number of successful if based on reliable data, can provide valuable introductions for 352 freshwater finfish species information on invasion threats in the form of introduced around the world. This score is based robust generalisations (Ricciardi and Rasmussen on the proportion of introduction events for a 1998; Ricciardi 2003). Kolar and Lodge (2002) species that resulted in an exotic population assessed exotic fish introductions toN orth establishing in (Arthington et al.’s (1999) America and Bomford and Glover (2004) assessed database). exotic fish invasions to Australia.T hese authors describe general factors which do not require 5. Introduction success rate for taxonomic expensive long-term research and can be used group for predictive risk assessments. Predictions from An analysis of data in Arthington et al. these approaches may not always give complete (1999) for introduction events for finfish around accuracy regarding invasion potential, but the low the world showed that introduction success cost of generating these predictions (compared to is strongly correlated with taxonomic group. the potentially high cost of losing endemic native Some families and genera have far higher communities and species to exotics) may make establishment success rates than others (Table them the best available for making decisions on 3). This score ranks fish species according to the import and keeping of exotic species. whether they are from families or genera with high or low success rates in Arthington et al.’s Risk assessment model (1999) database. Bomford and Glover (2004) listed five factors that they found were correlated with establishment success of exotic fish introduced to Australia.

1. Climate match to Australia This was calculated using the software model CLIMATE which matches meteorological stations in a species’ overseas range with meteorological stations in Australia (Knapp et al. 2006). CLIMATE projects the results onto a map of Australia with a splined grid surface, indicating how similar Australian climates are to climates where the species occurs overseas. Figure 1 presents an example of the input and output for Carp Cyprinus carpio based on presence records obtained from http://www.fishbase.org. A ClimateM atch Score for a species can be calculated by summing the number of Australian grid squares which have a high climate match to the species’ overseas range.

62 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Figure 1. Climate match for Carp Cyprinus carpio. a) meteorological stations in overseas range map digitised from http://www.fishbase.org. b) grid surface for Australia indicating levels of climate match: greens indicate good matches, yellows and light blue indicate poor matches.

a)

b)

-15 No data 0 -20 1 2 3 -25 4 5 6 -30 7

-35

-40

-45 120 130 140 150

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 63 Table 3. Establishment success rates for introduction events of families of freshwater finfish introduced outside their geographic range worldwide in descending order of success. Includes only families for which there are records of five or more introduction events* (data collated from Arthington et al. 1999).

Family Number of Number of Success rate % introduction events successful introductions Gobiidae 16 14 88 Cobitidae 8 7 88 172 144 84 Clupeidae 10 8 80 Loricariidae 5 4 80 Atherinidae 8 6 75 Osteoglossidae 8 6 75 Ictaluridae 105 70 67 Percidae 33 22 67 Channidae 15 10 67 Umbridae 9 6 67 Gasterosteidae 6 4 67 Belontiidae 47 31 66 Centrarchidae 171 112 65 Siluridae 15 9 60 Anabantidae 7 4 57 Esocidae 16 9 56 Cichlidae 466 252 54 Fundulidae 6 3 50 Catostomidae 25 12 48 Cyprinidae 707 316 45 Anguillidae 21 9 43 Centropomidae 10 4 40 Apocheilidae 5 2 40 Salmonidae 381 150 39 Clariidae 47 18 37 Osphronemidae 19 7 37 Moronidae 14 5 36 Helostomatidae 7 2 28 Characidae 33 4 12 Acipenseridae 28 1 4 Pangasiidae 5 0 0 Adrianichthyidae 6 0 0

* Data for families for which fewer than five introductions are recorded in Arthingtonet al.’s database are not included in this table.

64 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Bomford and Glover (2004) used these five factors for fish that have been recorded in the wild to develop a model for assessing establishment but have failed to establish exotic populations. risk for other species that could be released Most species that failed to establish get low or in Australia. A fish’s scores for each of the five moderate Establishment Risk Scores, whereas factors are summed to give a total Establishment most fish that successfully established get Risk Score. Figure 2 compares the Establishment serious or extreme scores. Risk Scores for exotic fish introduced to Australia that established exotic populations with scores

Figure 2. Establishment Risk Scores for 49 exotic freshwater finfish species introduced to Australia compared for successful and failed species. Most fish that successfully established exotic populations had scores of 15 or higher (serious to extreme risk ranks), whereas most fish which failed to establish had scores of 14 or lower (low to moderate risk ranks).

20

15 Successful introductions 10

5 Failed introductions Number of species Number of 0 ≤10 11-14 15-19 ≥20 Establishment risk score

often incomplete. Another potential problem Limitations to the risk is that the overseas geographic range of a fish assessment model may be restricted by predators, competitors or geographic barriers and the species may actually Bomford and Glover’s (2004) model has some be capable of living under a much broader range limitations. Clearly the inclusion of additional of climate conditions. In such cases climate variables for a fish’s environmental threshold matching may well underestimate the potentially tolerances, such as minimum and maximum climatically suitable areas for exotic fishes in water temperature, minimum dissolved oxygen Australia. Further, climate is only one out of a content and maximum turbidity would have whole suite of factors that might influence an been desirable. But data on these variables are exotic species’ distribution in Australia, so climate unavailable for many fish species, and these matching cannot be expected to give entirely values are not known for most Australian water accurate predictions of species’ potential ranges. bodies either. So unfortunately it was not feasible For example, although most of the Murray- to include them in the model. Darling Basin has a climate similar to that in Ruesink (2005) found that fish in families with places where Rainbow trout occur overseas, small body size and fish that are omnivores also this species is generally confined to cooler have higher establishment success so these upland streams and therefore may not spread two attributes could also be considered as in warmer slow-flowing waters. Despite these additional risk factors for establishment. She caveats, climate match maps give a reasonable also found that establishment success rose with general picture of climatic suitability of Australian endemism in the recipient country’s fish fauna. environments. However, to get more reliable Endemism is the proportion of native species predictions of the potential range of an exotic fish in a country that do not occur elsewhere – and species in Australia, it would be necessary to do Australia’s freshwater fish fauna is strongly more detailed analyses than Bomford and Glover endemic (Allen et al. 2002). (2004) undertook. One of the main problems with climate matching is that the overseas ranges of many fish are not well known. Data in www.fishbase.org is

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 65 The database in Arthington et al. (1999) shows (propagule pressure) as a risk factor in their that introduction success for exotic fish is model. However, aquarium species that have strongly correlated with the number of release a low commercial value and are widely kept events (Figure 3). Every species that Arthington in Australia are likely to be released more et al. (1999) recorded as being introduced more often, and these species are therefore likely than ten times established at least one exotic to have a higher risk of establishing exotic population. This suggests that most fish species populations. Frequent releases may also can establish exotic populations if they are occur of species popularly used as baitfish. released enough times. As it is not possible to Species that are valued for recreational predict how many times an exotic fish species fishing or as food may also be illegally introduced to Australia might be accidentally or released by people wanting to establish new illegally released, Bomford and Glover (2004) populations. did not include the number of release events

Figure 3. Correlation between the number of introduction events and the number of successful introductions for 352 freshwater finfish species introduced around the world (Data collated from Arthington et al. 1999).

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Applying the model to the are highly suited to establishing in the Murray- Darling Basin. Murray-Darling Basin The Redfin perch has an extreme Establishment Of the 33 exotic fish species known to be Risk Score in Bomford and Glover’s model established in the wild in Australia (Table 2), but only has a high climate match to the very four have a high climate match to most of the south eastern corner of the Murray-Darling Murray-Darling Basin: Carp, Mozambique tilapia, Basin. The Oriental weatherloach has a serious Rainbow trout and the Guppy. These four species Establishment Risk Score in Bomford and also score an extreme Establishment Risk Score Glover’s model but only has a fairly low climate in Bomford and Glover’s model. Another two match to the Murray-Darling Basin. This is species that are already established in Australia probably an under-estimate of the Oriental have high climate matches to the north of the weatherloach’s climate match because the Basin (Sailfin molly and Platy), and these two overseas range for the Oriental weatherloach species also both have extreme Establishment given in FishBase does not include its introduced Risk Scores. Four species have high climate range in America. matches to the south of the Basin (Tench, Two species which have been found in Australian Goldfish, Brown trout andR oach) and the first waters, but which are not yet known to have three of these have an extreme Establishment established in breeding populations in Australia, Risk Score and the Roach has a serious have good cimate matches to the Murray- Establishment Risk Score. Hence Bomford and Darling Basin. The blue tilapia has an extreme Glover’s model predicts all ten of these species Establishment Risk Score in Bomford and

66 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Glover’s model and also has moderately good • have a good climate match to Australia climate match to the north of the basin. The because such species are more likely to Atlantic salmon has a serious Establishment Risk establish over large areas so their impacts will Score and has a very high climate match to the be spread more widely. south of the Basin. This list can be used to get a qualitative Fishbase lists another 27 exotic fish species that assessment of the risk a fish poses of becoming a are reported as environmental pests overseas but pest if it establishes a wild population. which have not yet established in Australia. Five of these species have high climate matches to the Murray-Darling Basin and also have extreme Management implications Establishment Risk Scores in Bomford and There are estimated to be over 22 million exotic Glover’s model: Bluegill Lepomis macrochirus, fish kept in Australia, representing over 1000 Largemouth bass Micropterus salmoides, Black different fish species M( cNee 2002). Fish of many bullhead Ameiurus melas, Nile tilapia Oreochromis species are frequently released into Australian niloticus and Stone moroko Pseudorasbora parva. freshwater bodies. If a new species establishes and spreads beyond a small enclosed water body, eradication is rarely possible, and would usually Assessing potential impacts be prohibitively expensive to attempt (Bomford Some exotic fish species are known to have and O’Brien 1995). Therefore investment is devastating impacts. For example, the exotic needed in education to improve community Nile perch in Lake Victoria, Africa, caused the awareness of the consequences of releasing extinction of over 200 species of native cichlid exotic fish.I t may also be desirable to introduce species (Welcomme 1988). major penalties for the illegal trade, keeping A review of factors associated with adverse and particularly release of exotic fish if evidence impacts of exotic freshwater finfish shows that shows this will help reduce risk of new reliable knowledge about impacts is sparse high risk species being introduced into the (Bomford and Glover 2004). There is insufficient Murray-Darling Basin. reliable knowledge of the factors correlated with The Australian Government Department of the impacts of exotic fish to make the development Environment and Water Resources now conducts of a quantitative model feasible for assessing reasonably robust risk assessments to prevent the risks of impact for new species of exotic fish the introduction of new exotic fish species that in Australia. Nonetheless, Bomford and Glover could become future pests in Australia. But (2004) suggest adverse impacts are most likely to there are still over 1000 species already in be cause by exotic freshwater finfish that: Australia for which no risk assessments have • have adverse impacts elsewhere; yet been conducted. Risk assessments are needed on all the species that are kept and • have close relatives with similar behavioural traded so that an alert list of high-risk species and ecological strategies that cause adverse can be developed (Kailola 2000). All the data impacts elsewhere; needed to use Bomford and Glover’s (2004) • are generalist feeders; risk assessment model is available in http:// • are piscivorous; www.fishbase.org.T he model does not require • destroy or modify aquatic vegetation or stir up expert knowledge and it usually takes less than sediments to increase turbidity; an hour to assess a fish’s EstablishmentR isk Score. Although the results generated by the • have the potential to cause physical injury; model will have a degree of uncertainty, more • harbour or transmit diseases or parasites that detailed assessments could be conducted on are present in Australia; the species that get high Establishment Risk • have close relatives among Australia’s Scores, including more accurate determinations endemic fish (hybridization, competition); of their overseas ranges and history of • are known to have spread rapidly following establishment success overseas. CLIMEX, a their release into new environments; and CSIRO climate matching package, can take a species’ environmental tolerances into account when predicting its potential range (Sutherst and Maywald 1999). CLIMEX analyses take more time and expertise and require knowledge on

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 67 a species’ biology but would be worth doing for species of key concern to Murray-Darling References Basin managers. The pest potential of species Allen, G.R., Midgley, S.H. & Allen. M. 2002. Field that get a high Establishment Risk Score could guide to the freshwater fishes of Australia. Western Australian Museum and CSIRO Publishing, also be assessed by appropriately qualified Collingwood, Victoria. fish biologists.S pecies found to have both high Arthington, A.H., Kailola, P.J. Woodland, D.J. Establishment Risk Scores and attributes that & Zalucki, J.M. 1999. Baseline environmental make them likely to be pests could be placed data relevant to an evaluation of quarantine risk on the alert list and community education potentially associated with the importation to about exotic fish could focus on these species. Australia of ornamental finfish.R eport to the Regulations restricting their trade and keeping Australian Quarantine and Inspection Service, might also be desirable. Department of Agriculture, Fisheries and Forestry, Canberra. For the 33 exotic fish species already Bomford, M. & Glover, J. 2004. Risk assessment established in the wild in Australia, those that model for the import and keeping of exotic pose a high to extreme risk to the Murray- freshwater and estuarine finfish. Bureau ofR ural Darling Basin could have some more in-depth Sciences, Canberra. risk assessments conducted. But even if the Bomford, M. & O’Brien, P. 1995. Eradication or future spread and pest potential of these control for vertebrate pests? Wildlife Society Bulletin established species is accurately predicted, it 23: 249–255. is unlikely that containment efforts will prevent FishBase http://www.fishbase.org their spread if conditions are suitable. Kailola, P.J. 2000. Development of an alert list for non-native freshwater fishes.U npublished final report to Environment Australia, Canberra. Conclusions Knapp, S., Brown, L. & Barry, S. (2006 in prep.) Although several species of exotic fish are Climate Software Manual. Bureau of Rural already considered to be pests in the Sciences, Canberra. Murray-Darling Basin, many more potential Kolar, C.S. & Lodge, D.M. 2002. Ecological pest species are being kept in Australia. Some predictions and risk assessment for alien fishes in North America. Science 298: 1233–1236. of these species are likely to establish wild McNee, A. 2002. A national approach to the populations in the Murray-Darling Basin if management of exotic fish species in the aquarium appropriate preventative action is not taken trade: An inventory of exotic freshwater species. to prevent accidental or illegal releases. Most Bureau of Rural Sciences, Canberra. fish species can probably establish if they are Ricciardi, A. & Rasmussen , J.B. 1998. Predicting released enough times. Therefore educating the the identity and impact of future biological community about the risks of releasing exotic invaders: a priority for aquatic resource fish is essential. management. Canadian Journal of Fisheries and Aquatic Sciences 55: 1759–1765. Risk assessments are needed to develop an alert list for the most significant potential pest Ruesink, J.L. 2005. Global analysis of factors affecting the outcome of freshwater fish species. It is desirable for risk assessments introductions. Conservation Biology 19: 1883–1893. to be conducted for all the exotic fish species Sutherst, R.W. & Maywald, G.F. 1999. CLIMEX: currently kept in Australia. Priority should be predicting the effects of climate. CSIRO Publishing. given to those species which are widely kept and http://www.weedinfo.com.au/bk_climx.html. those which have established exotic populations Welcomme, R.L. 1988. International Introductions elsewhere. Species which get a high score for of Inland Aquatic Species. Food and Agriculture establishment risk and/or have attributes that Organisation Fisheries Technical Paper 294. FAO make them likely to be pests if they were to United Nations, Rome. establish in the wild could be placed on an alert Williamson, M. 1999. Invasions. Ecography 22: 5–12. list. Community education could focus on the risks posed by these species. Efforts to prevent new exotic fish species establishing in the wild are likely to be more successful and be a more efficient use of resources than attempting to eradicate or contain exotic fish once they have established wild populations.

68 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Community understanding and attitudes to alien fish

Adrian Wells Murray Darling Association, National Carp & Pest Fish Task Force, Community Stakeholder Taskforce - Native Fish Strategy, PO Box 359 Albury NSW 2640.

Introduction People spread alien fish About a dozen alien fish occur in the wild The most important and initial part of any across the Murray-Darling Basin. Their range community engagement on managing alien fish and impacts vary. Some are present in pest must recognise that it is people who spread proportions and further introductions are alien fish, sometimes accidentally, sometimes inevitable over time. Regardless of how good out of ignorance or fear, sometimes deliberately the science is, how well the technology is tested through callous acts, or because of poor and how thorough the awareness strategies understanding of the impacts of these fish on are, history tells us again and again that if the river systems. community has different attitudes to pest and Even though it is illegal, some people use live alien animals or plants or does not feel engaged alien fish for bait.T his was demonstrated in or involved in the management of those aliens, it Queensland where primary school children will be difficult to implement control measures. along the Balonne River delighted in explaining The introduction of myxomatosis was strongly how they used ‘native Carp’ (goldfish) as live opposed in New Zealand because of the low level bait. Furthermore, unwanted aquarium fish of community understanding and awareness are unfortunately still being thoughtlessly and about the disease and the lack of clear and illegally disposed of in our waterways. accurate information to help the public develop an informed opinion. A report concluded that the release of this type of biological control of pests Attitudes ‘will ultimately depend on an assessment done by Our current attitudes to alien fish have been governments of community attitudes’. determined very much by our predominantly Plans by the Pest Animal Control Cooperative European heritage although this may be changing Research Centre to shoot destructive wild horses with attitudes from other cultures and countries. by helicopter several years ago in the Northern I am not sure we know or understand very much Territory had to be stopped at the last minute about the attitude of more recent migrants because of poor community consultation. to Australia towards fish and fishing in the Developing strategies to manage alien fish in the Murray-Darling Basin. However, it is encouraging Murray-Darling Basin by identifying community to note that some fisheries agencies are attitudes and implementing good community developing brochures on Tilapia in languages engagement about the fish and their control other than English. methods is no different. A small but important There was a determined push by the community example was demonstrated recently. As CSIRO in the 1990’s to rid the Basin’s waterways of investigates the potential of the Koi Herpes virus Carp. And since then, there has been significant to manage Carp, the organisation will have to investment by governments and industry in engage the animal welfare lobby to ensure it is managing Carp. But while our knowledge and happy with the way the virus may actually information about Carp has greatly improved, kill the fish. community attitudes do not seem to have changed as dramatically as anticipated.

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 69 Anecdotally, from a series of community and local levels but all have approached the table meetings over the past three years, reduced with differing attitudes and values. For example, rainfall, continuing drought, low water levels, in the Glenelg catchment in western Victoria, the declining Carp populations and environmental community wanted to get rid of Carp but some flows have now placed Carp way down on the list sectors wanted slightly different outcomes. of priorities of many river communities. Scientists wanted to look at using native fish Carp continue to be the most widely known of as predators; the community and recreational our alien fish andI suspect that community anglers supported that decision but saw an attitudes to the other alien fish are likely to be opportunity to introduce Murray cod and Golden coloured by the Carp experience, even though perch in a large reservoir to create recreational the nature of these other alien fish differ. and tourism opportunities. It is my view that the community is generally unaware of the other alien fish in the Basin or Agency attitudes the threats they pose. Some are even regarded as native as demonstrated by the mayor of a I believe that it is not just community attitudes community in southern NSW who some time that need to be addressed. When the ago, proudly and publicly at a naturalisation Murray Darling Association was preparing a ceremony, hailed trout in the local stream as a brochure on alien fish two years ago,NS W and native fish. Victorian fisheries agencies were worried about our intention to clearly state that trout and Redfin Some of us will recall the battle several years ago perch were alien fish. Agency staff claimed that to stop the World Coarse Fishing Championships recreational anglers would be upset by this being held in Lake Burley Griffin, only to be but when I spoke to a couple of peak bodies on told by the ACT Government that the economic this issue, they seemed less nervous than the and tourism benefits far outweighed other government agencies. In fact, some agreed that considerations, a decision that sends the wrong trout have certainly contributed to the decline message to the community about Carp. of galaxiids, eat young native fish and compete We can be very amused at these anecdotes but with some native species for food and space. it indicates the challenges ahead when wanting Interestingly, some representatives of the peak to control alien fish, some of whom have the fishing groups also agreed with theNative Fish potential to make Carp look like ‘a Sunday Strategy that trout need to be better managed. school picnic!’ On what evidence I can find, and Developing this brochure also identified an much is anecdotal, community attitudes to alien ongoing debate on how to even define fish that fish certainly vary but will play a key role in are not native to the Murray-Darling Basin. There their management. was some reluctance to identify trout and Redfin There is evidence in Queensland that Tilapia are perch as alien species even though they have being actively dispersed by the community in the impacted significantly on some native fish and same way as Carp. Tilapia is seen as a good their habitats. The aim is not to eradicate these fish for both angling and eating.I was in a fish but rather manage them more effectively restaurant in Adelaide recently which offered and restrict their impacts where possible, a view ‘Tilapia’ as a main dish. To me, this is sending supported by communities that rely on trout the wrong message to the community and fishing for their economic and social benefits. underlines the importance of engaging with I also understand that when the Murray- people, including in languages other than Darling Basin Commission’s Native Fish English, to discuss the problem. Strategy document was being prepared, some The community has started to notice the State agencies wanted Redfin perch given less alarming spread of Oriental weatherloach prominence as an alien fish. along the Murray River and yet there is little community information about this fish.T here seems to be even less focus or coordination amongst scientists and fisheries agencies to start to develop control strategies. Over the last 10 years, managing Carp has involved a lot of players and multiple stakeholder input into management plans at national, state

70 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 Aboriginal community Carp project made an attempt when it engaged a consultant to research what was the first attempt attitudes to quantify community attitudes to using gene technology to manage Carp. As we look at the alien fish issue, we must also consider and engage Indigenous communities A key issue in researching attitudes is to first of and acknowledge that they may also have all identify what attitudes we are looking for. Do differing and varying attitudes. we have any idea what the drivers of community attitudes to alien fish or even native fish are? During several discussions with the Yorta Yorta What are the attitudes amongst governments and Nation in northern Victoria, the Yorta Yorta people researchers that may need to be challenged to made it clear that they see Carp as a problem implement management programs? but they are of no commercial interest. Also, they will not eat Carp, only bury them. Yet, in other Discussions at community forums about native parts of the Murray-Darling Basin, Aboriginal fish and carp indicate to me that the community communities have made some attempts to exploit may be further ahead in its thinking about alien Carp for commercial gain but with little success. fish than government agencies At the launch of the Invasive Animals Cooperative It is clear to me however, that we need a review or Research Centre in Canberra in August 2005, research project on social attitudes and reasons Indigenous people drew attention to the fact as to why people continue to want to introduce that some Aboriginal communities might resist potential pest fish into Australia and why people wholesale slaughter of aliens as this type of continue to distribute alien fish in our waterways. control is contrary to their culture. In a book on The Invasive Animals Cooperative Research the impacts of Carp in Australia (Koehn et al. Centre recently engaged a social researcher to 2000), the authors note that Indigenous people undertake a related study. also fear the use of biological control for alien Do we even know what questions to ask when fish, particularly viruses.T his is not only because seeking information about community attitudes of their potential impact on iconic native fish to alien fish, because only the right questions important to Aboriginal culture but because of will provide the right and useful answers? I am the deadly impact of introduced viruses and reminded of questions put by the media to people diseases on Indigenous populations over the of NSW when the debate about using treated past 200 years. effluent to help overcome water shortages.H ow One thing that has become apparent is that many times did I hear in the media the question, Aboriginal communities in the Murray-Darling “Would you drink sewage water?” Certainly a vital Basin see the huge numbers of Carp as denying and current issue, but the wrong question! them the opportunity and right to catch native There are also changing attitudes to alien fish fish to supplement their diet, an activity that is that need to be kept in mind. From a number firmly embedded in their culture.I suspect that of youth forums that the Murray Darling they would hold similar views on other alien fish. Association have run over the past five years, And it is worth stating again that when Aboriginal young people are increasingly confusing Carp communities participate in controlling alien fish, as a native species. We sometimes forget that they need to be involved as mainstream partners, new generations have never seen rivers in the not singular or separate entities. Basin free of alien fish. At the same time there are some subtle shifts in community attitudes to eating Carp, even though Carp and Tilapia are the Researching attitudes most eaten freshwater fish in the world. AS outh I mentioned that much of what I can tell you is Australian Carp fishermen told me recently that anecdotal – and that is part of the problem. rising prices and shortages of more traditional fish in Australia are making people look at Carp We are good at raising awareness and passing as a cheap source of fish.M illions around the on information about alien fish. We are good at globe seems to know about the nutritional and developing control strategies. We are reasonably price value of Carp as a fish - except Australians. good at engaging communities on alien fish issues. However we have not been good at researching the attitudes that can play a key role in managing or eliminating these problem fish. The Pest Animal Control CRC’s Daughterless

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 71 Community willingness In summary to be involved • The community wants to be involved in managing alien fish The responsibility for controlling alien fish rests with the entire community of the Murray-Darling • Involvement can lead to ownership Basin, not just researchers or governments. • Community understanding and attitudes will Experience with Carp has shown the willingness affect strategies to manage alien fish of the community to contribute to managing • People are the principle means of these fish these pests and improve opportunities for native being spread fish. A key to this has been the provision of good, • There is little community knowledge on alien accurate and correct information. fish and their impacts apart from Carp As we have found with Carp, trying to manage • Attitudes of agencies towards alien fish need alien fish in isolation will not have a significant to be addressed impact on rehabilitating native fish populations. However, an integrated approach will make a • Indigenous knowledge and attitudes must be difference managing these fish and contribute to considered the success of the Native Fish Strategy. • Information and education is not the same as Even referring to some alien fish as ‘pests’ can engagement be a problem as it may focus attention on just • The key to community engagement is good, getting rid of the fish and not addressing the key accurate and up-to-date information issues of degraded habitats and changes to river • Engagement may need to be in languages environments that encouraged the alien fish in other than English the first place. • Remote communities should not be ignored because of isolation Community engagement • There is an urgent need to research community attitudes to alien fish. It is also worth pointing out something about community involvement. There are a number of terms that get flung around on this topic – References community education, community awareness, Koehn, J.D., Brumley, A.R. & Gehrke, P.C. 2000. communication, community participation, Managing the impacts of carp. Bureau of Rural community engagement. To me, they all mean Sciences, Canberra. slightly different things. You can have lots of community awareness but poor community engagement. You can develop great community education strategies, but if there are no people to implement them, they are worthless. Good information does not assume good community engagement. Lots of media releases do not mean good communication. Also, even though people will want to be involved, they will want to participate at various levels and capacities.

72 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006 List of participants

Dean Ansell Adrian Harvey Murray-Darling Basin Commission Rural Solutions SA Natalie Baker Sarah Hatch Queensland Department of Primary Department of the Environment Industries and Fisheries and Heritage Bill Bardsley Jason Higham New South Wales Department Rural Solutions SA of Primary Industries Michael Hutchison Plaxy Barratt Queensland Department of Primary Queensland Murray Darling Committee - Border Industries and Fisheries Rivers Catchment Management Peter Jackson and Landcare Queensland Department of Primary Jim Barrett Industries and Fisheries Murray-Darling Basin Commission Frank Keenan Keith Bell Department of Natural Resources K&C Fisheries Global Pty Ltd and Mines Mary Bomford Peter Kind Bureau of Rural Sciences Queensland Department of Primary Industries and Fisheries Ben Bowman Department of Primary Industries - John Koehn Fisheries Victoria Arthur Rylah Institute Craig Boys Brian Kuhn Murray-Darling Basin Commission Nobby & District Fishing Club Mike Braysher Chris Kuhn University of Canberra Nobby & District Fishing Club Lindsay Chadderton Ron Lewis New Zealand Department of Conservation Native Fish Australia Wayne Fulton Mark Lintermans Primary Industries Research Victoria Environment ACT Alice Fistr Adam Logan Primary Industires and Resources Queensland Murray Darling Committee Inc South Australia Alex McNee Dean Gilligan Bureau of Rural Sciences New South Wales Department Damian McRae of Primary Industries Australian Government Department Natasha Grainger of Environment and Heritage Department of Conservation Andrew Norris Ivor Growns Invasive Animals CRC New South Wales Department Malcolm Pearce of Natural Resources Queensland Department of Primary Michael Hammer Industries and Fisheries Aquasave Consulting Tarmo Raadik John Harris Arthur Rylah Institute Harris Research

Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 3v0-31 May 2006 73 Rebecca Richardson WWF-Australia John Russell Queensland Department of Primary Industries and Fisheries Ben Smith South Australian Research and Development Institute Peter Teakle SA Fish & Game Brad Tucker Invasive Animals CRC Adrian Wells Murray Darling Association Qifeng Ye South Australian Research and Development Institute

74 Emerging Issues in Alien Fish Management in the Murray Darling Basin – Workshop, 30-31 May 2006

Emerging Issues in Alien Fish Management in the Murray-Darling Basin Statement, recommendations and supporting papers