Emerging Issues in Alien Fish Ma nagement in the Murray

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Rivers
KNOWLEDGE
Emerging Issues in Alien
Fish 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 AddressGPO Box 409, Canberra ACT 2601
Office locationLevel 5, 15 Moore Street, Canberra City, Australian Capital Territory
Telephone
Facsimile
E-Mail
Internet
(02) 6279 0100 international + 61 2 6279 0100
(02) 6248 8053 international + 61 2 6248 8053
[email protected]
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
Graphic design by Art Direction Creative, Manuka ACT
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
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Contents
Foreword
5
Statement and Recommendations
7
Alien species in the context of the Native Fish Strategy
Jim Barrett
16
Overview of the ecology and impact of three alien fish species: Redfin perch, Mozambique mouthbrooder
(Tilapia) and Oriental weatherloach
Mark Lintermans, Tarmo Raadik, David Morgan and Peter Jackson
22
Management of pest fish
Mike Braysher
33
Summary of existing alien fish management
mechanisms in Murray-Darling Basin jurisdictions
Jason Higham
40
Managing pest fish in the Murray-Darling Basin:
lessons learnt from previous invaders
John Koehn
54
Risk assessment modelling to identify potential fish invaders
Mary Bomford
60
Community understanding and attitudes to alien fish
Adrian Wells
69
List of participants
73
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Foreword
Of the 13 objectives of the Native Fish Strategy
(NFS), one relates directly to alien species,
namely to ‘control and manage alien fish species’.
Another two objectives are relevant in that the
improved management of alien fish will assist
to protect native fish from threats of disease
and parasites, and protect native fish from the
adverse effects of translocation and stocking. In
addition, ‘controlling alien fish species’ is one of
the six driving actions of the NFS.
The NFS aims to ensure that the Basin sustains
viable fish populations and communities
throughout its rivers. The 50-year goal of the
NFS is to rehabilitate all native fish species in
the Basin back to 60 percent or more of their
estimated pre-European settlement levels.
Importantly, alien fish should not be regarded
as more important than other threatening
processes. Without addressing other threats such
as habitat degradation, lack of environmental
flows, barriers to fish passage and various water
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
the management of three particular species.
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.
The Workshop examined in detail some of the
more pertinent issues relating to alien fish in
the Basin, including control and management;
prevention and preparedness; policy, reporting
and decision making; and extension and
communication. The need to develop a ‘toolbox’
of up-to-date management and control
techniques was identified by participants. The
workshop also recommended the development
of a Basin-wide alien fish plan and the MDBC
has consequently provided funding for this
initiative, to commence in 2007/08.
This Workshop is another in a series that
have been conducted over the last few
years to address specific issues under the
banner of the NFS. Previous workshops have
addressed the need for fishways, thermal
pollution, translocation and stocking,
downstream migration, habitat rehabilitation
and management, the conservation and
management of Murray cod, and fish in wetlands.
Wendy Craik
Chief Executive
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Emerging Issues in Alien Fish Management
in the Murray-Darling Basin
Workshop
30-31 May 2006
Statements and
Recommendations
priority action in the development of the Basinwide alien fish plan.
•
It was noted that the wealth of existing
international literature on the management of
alien fish species should be acknowledged and
utilised in developing management options in
the Basin.
•
The workshop participants agreed to a basic
framework that contains the components
considered central to the management of alien
species and is flexible enough to
allow interpretation and adoption at a
range of scales.
•
Workshop participants agreed that it will
be critical to invest in a communication and
education program about the detrimental
impacts of alien species and the consequences
of moving them to new catchments. Coupled
with this should be an increasing investment
in social research. This should focus on
understanding the values, knowledge levels
and behavioural drivers in communities.
1. Introduction
We, the participants of the workshop on Emerging
Issues in Alien Fish Management
in the Murray-Darling Basin, held in Brisbane
on 30 -31 May 2006, and representing a range
of stakeholders, professionals and interests,
request that the Commonwealth and State
Governments and other agencies, community
groups and those with an interest in the
management of alien fish species consider the
following statements and recommendations
arising from consideration of expert papers
and discussions.
Alien species are here defined as species
originating overseas and now established in
Australia (Harris, 1995). This definition excludes
translocated native species and these were not
specifically considered at the workshop. However
workshop participants recognised that many
of the recommendations documented here are
equally applicable to these species.
2. Summary Conclusions
•
It was the firm view of the workshop
participants that there is an urgent need for
alien species management in the Basin to be
developed and implemented under a Basinwide alien fish plan. This should be seen as a
component of, and be driven by the principles
of the Native Fish Strategy. It should have
specific objectives, milestones and targets.
•
It was the firm view of the workshop
participants that immediate action to reduce
the risk of alien species already in the Basin
spreading further or of new alien species (such
as Tilapia) entering the Basin constitutes a
3. Reasons for concern
3.1 What is the problem?
•
Much emphasis has been placed on the
impacts of Carp in the Murray-Darling Basin
with little consideration being given to the
impact of other species, particularly those that
are either not yet widespread (e.g. Oriental
weatherloach) or are not yet present but have
the potential to invade the Basin (e.g. Tilapia),
or those with economic or social values (e.g.
trout, Redfin perch and ornamental fish) in
southern states.
•
Whilst definitive data are lacking on the
potential impact of some of these species on
the receiving ecosystems, their invasive nature
suggests that significant impacts are likely.
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•
Evidence suggests that there is a limited
capacity to minimise the risk of alien species
spreading through the Basin, preventing new
species entering the Basin or detecting new
invasions before they become established.
Neither is there evidence that techniques are
available to control new outbreaks of these
species where eradication of new infestations
is not possible.
•
Protect native fish populations and habitats by
minimising the risks of:
-Already established alien species spreading
further in the Basin.
-The introduction of new species to the
Basin from those established outside its
catchment.
-New species establishing in the Basin
that currently do not have self-sustaining
populations elsewhere in the country.
•
Establish techniques to enable, where
appropriate, alien species to be controlled
where local eradication is not possible.
Currently restricted species such as Oriental
weatherloach will increase their range within
the Basin.
•
Underpin management decisions with science.
Given the close proximity of existing Tilapia
populations in south-eastern Queensland, it is
only a matter of time before infestations occur
in the Northern Murray-Darling Basin.
•
Reduced risk of spread of alien species
throughout the Basin.
•
Collective knowledge across jurisdictions and
co-ordinated approach leading to more effective
management.
•
Better targeted research leading to better
management outcomes.
•
Improved river health and aquatic biodiversity.
•
Enhanced rehabilitation of native fish
populations.
3.2 What will happen if the problem
is not addressed?
Based on the collective experience of the
workshop participants (see Appendix page 73),
the workshop has concluded that the following
will result if this problem is not addressed:
•
•
•
•
•
•
The threat of additional alien species entering
the Basin via the ornamental fish trade
will continue.
Lack of effective removal techniques
will hamper the local eradication of new
infestations even if they are detected early.
Lack of effective control techniques
will lead to an inability to control populations of
these species where eradication has failed.
The further spread of existing and newly
introduced alien species will significantly
impact on native fish populations and habitats
and will help to confound current interventions
in the Basin aimed at rehabilitating native
fish populations.
•
Alien species will impact on the value of
recreational and commercial fisheries.
•
Alien species will continue to impact on
Aboriginal communities of the Basin.
•
Lack of action now will lead to the need for
highly expensive control actions in the future
(ie. prevention is better than cure).
4.2 Benefits
4.3 Beneficiaries
•
Riverine ecosystems.
•
Native fish populations.
•
Fishers, tourism agencies, scientific
community, future generations etc.
•
General community through mitigated alien fish
impacts and reduced control costs in the future
by acting now.
4.4 Opportunities
•
There are existing initiatives that can be used
as vehicles to achieve a Basin-wide approach,
these include:
-The Murray-Darling Basin Commission
including the Native Fish Strategy;
4. Goals, benefits and opportunities
-The National Ornamental Fish Policy
Implementation Group;
4.1 Goals
-The Invasive Animals Cooperative Research
Centre (IA CRC); and
-Natural Heritage Trust funding.
•
8
the Basin and is properly integrated with other
management actions.
Under the auspices of a Basin-wide alien
fish plan, establish a framework for the
management of alien fish species that leads to
a consistent and coordinated approach across
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•
An opportunity exists for the IA CRC to broaden
its focus beyond Carp and Tilapia to include
other priority alien species.
•
The Vertebrate Pest Committee (VPC) now has
aquatic vertebrate pests as part of its brief.
•
•
•
Use of Natural Resource Management
regional contact officers may be possible to
support communication of issues about alien
species.
Progress is being made in establishing
protocols for national rotenone use permits
and registration.
Opportunities exist for International
collaboration with New Zealand and the
United States of America in both science and
management.
•
Communities throughout Australia are
becoming more informed about pest species
and recognise the associated problems.
•
The recent nomination to list the spread of
alien fish as a Key Threatening Processes
under the Environment Protection and
Biodiversity Conservation Act 1999 (EPBC Act)
could be used to help facilitate coordinated
action across the Basin.
•
An opportunity exists to improve the dialogue
with the ornamental fish industry and angling
fraternity to create better understanding and
to inform both parties about alien species
initiatives.
•
The opportunity exists to develop a Basinwide plan to combat alien fish, including a
Geographic Information System (GIS) based
database, allowing efficient and rapid transfer
of information and improved communication.
4.5 Potential limiting factors
•
There are currently few control and
management tools available to agencies.
•
The limited lifespan of the IA CRC may
threaten availability of research funding and
strategic direction in the long term.
•
There is currently a lack of social science
information on cultural practices and values
for communities within the Basin.
•
There exists a range of diverse and often
conflicting views about the value of alien
species. Whilst some people perceive these
animals as disruptive and a threat to native
species and systems, others value some of
these alien species because of food, economic,
cultural or recreational values.
•
Inter-jurisdictional variability in legislation,
policy and response processes forms a
significant barrier to consistent, cooperative
and effective Basin-wide management.
•
Limited resources and competing natural
resource management priorities may hinder
capacity to manage alien fish species.
•
The issue of conflicting policies and
management responses between fisheries
and conservation agencies within some
jurisdictions may inhibit progress.
•
There is an undefined process for cost-sharing
arrangements to deal with invasions of
national significance.
•
Social marketing skills are not being
adequately used in alien fish management.
5. Specific Recommendations
5.1 Introduction
The workshop recognised that while there
are some significant knowledge gaps, there
is a range of very tangible and immediate
actions than can and should be taken to begin
addressing the problem. A framework (Figure
1) that emerged from the workshop discussions
contains the components considered central to
the management of alien species and is flexible
enough to allow interpretation and adoption at
a range of scales. The recommendations from
the workshop will be presented within this
framework construct. The workshop identified a
number of principles that should form the basis
for the implementation of all recommendations.
These principles are;
Interdependency of framework components. It is
acknowledged that to reduce the actions required
to achieve the goals of the alien species plan to
discrete components is synthetic and is done
for expediency. The interdependencies that exist
between these components are acknowledged
and understood.
Cultural diversity. The cultural diversity within
the Australian population is acknowledged.
This diversity demands an equally diverse array
of strategies for specific approaches in the
extension effort and the application of science in
the Murray-Darling Basin.
Science-based decision-making. It is
acknowledged that all decision making should
be based upon good science and should not
compromise the integrity of scientific information.
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Governance. It is acknowledged that there are
four levels of governance that will need to be
considered within the implementation processes;
Federal, State, Regional and Local.
Systemic perceptions. Alien species should be seen
as part of a broader system of natural resource
management initiatives. Interdependencies
between these initiatives should be
constantly considered.
•
Develop management mechanisms that
will actively pursue and continually promote
greater consistency in alien aquatic fauna
management and funding across all levels of
governance within the Murray-Darling Basin.
This consistency across jurisdictions should
include species status, legislative controls,
response processes, planning and education.
•
Ensure that the VPC deliberations include
alien fish management. Develop a specific
agenda paper for the VPC that outlines alien
fish species management requirements
including costs, benefits, responsibilities
and timeframes so adequate resources are
provided to effectively address relevant alien
fish issues.
•
Support the nomination for listing of the
‘introduction of fish outside their range’ as a
key threatening process under the EPBC Act
and State legislation.
•
Initiate processes to allow alien fish
management to be integrated with other
alien species natural resource management
initiatives. This may embrace both terrestrial
and aquatic dimensions and include both plant
and animal targets.
•
Develop criteria for determining the success of
management actions.
•
Define the key outcomes of alien species
management within the context of broader
ecosystem management.
•
Undertake pathway analysis (i.e. the possible
pathways by which an alien fish species can
invade a waterway and the associated vectors
and risks of each component of the pathways)
as an independent component of alien fish
management and integrate the results
into control, prevention and engagement
strategies. Explore efficiencies to be gained
by linking with other response programs and
organisations.
5.2 Recommended priority actions
The priority actions listed may be conducted
over both short and long time frames. Decisions
need to be made about the development of action
plans and these decisions will be at all four levels
of governance (see above). This acknowledges
that the importance of specific actions may vary
within species, geographic locations and existing
policy demands across the Murray-Darling
Basin. Management actions for alien fish will be
undertaken within broad pest
management principles.
5.2.1 Alien species management
Workshop participants identified the need for a
number of overarching management actions and
areas of policy development that were required
if more effective alien species management was
to occur in the Basin. These priority actions are
outlined below:
•
10
Develop and implement a Basin-wide alien
species plan. This should be seen as a
component of the Native Fish Strategy (NFS)
and be guided by the principles of the NFS. This
plan should act as a driver for a complementary
State and national based approach. The plan
should also recognise and define the roles,
responsibilities and cost-sharing arrangements
of stakeholders. The plan should include, but
not be restricted to:
-Rapid response components (may be
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.
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5.2.2 Prevention and preparedness
used to develop appropriate management.
This consideration of ‘values’ acknowledges
the differences that exist within community
perceptions of alien fish. These differences
include values of: desirable recreational
fisheries; negative impact on native species
and communities; commercial industry;
spiritual, religious and cultural connections;
and indigenous culture.
Workshop participants recognised that high
priority must be given to the prevention of new
infestations of alien fish species in the Basin.
Reduction in the risk of new infestations will only
be achieved if appropriate response mechanisms,
resources and expertise are in place across the
Basin. Key actions required to achieve this are
outlined below:
•
•
Establish dedicated full time alien fish
management teams in jurisdictions throughout
the Murray-Darling Basin. These teams will
have a primary responsibility for rapid response
actions with additional responsibility including
community liaison activities as prescribed by
both the overarching plan and local needs.
Conduct a risk-based assessment for new,
potential and existing invaders. This should
initially cover assessments of all species known
to have been imported to develop an alert list.
An assessment of other potential invaders that
have been successful overseas should also
be undertaken. The resultant alert list should
inform alien species management including
education programs, legislative controls and
enforcement activities.
•
Establish a contingency/emergency fund for
alien species management to ensure resources
for preparedness and on-ground rapid response.
•
Further develop and adopt the ‘vulnerable
catchment’ (i.e. catchments susceptible to
infestation by a particular alien species)
approach to prioritise management.
•
Collaborate with the National Ornamental Fish
Policy Implementation Group, or its successors,
the aquarium industry and hobby groups such
as the Australia and New Guinea
Fishes Association.
•
Strengthen and support community-based
detection and prevention programs.
•
Ensure indigenous participation in the
management of alien species and engagement
of indigenous communities is a priority.
•
Define roles, responsibilities and
accountabilities of stakeholders in alien fish
species management.
•
Engage other stakeholders such as nonfisheries agencies, regional natural resource
management bodies, private sector and the
broad community in alien fish
management processes.
5.2.4 Extension and communication
Workshop participants recognised that most
new infestations of alien fish species result
from human intervention. For example, there is
ample evidence that Tilapia are still being actively
spread to new catchments in Queensland by
accidental or deliberate introductions by people.
The dangers associated with introducing alien
fish species are not clearly understood by all
sectors of the community. Priority actions to
address these issues are outlined below:
•
Increase the investment in communication
activities for alien fish across the MurrayDarling Basin. This should be driven by a
communications strategy and should target
raising awareness and knowledge of a range
of stakeholders (e.g. general public, specific
groups, management agencies, politicians,
anglers etc).
•
Increase social research focusing on
understanding values, knowledge levels and
behavioural drivers in communities. The
results of this research should act as a guide
to allow extension strategies to accommodate
value differences within the Basin.
•
Direct specific extension efforts toward
indigenous communities throughout the
Murray-Darling Basin.
•
Identify other social diversities (ethnic,
cultural, interest, spiritual) in communities
and tailor engagement and communication
activities to reflect this.
5.2.3 Policy, reporting and decision making
The management of alien fish species must be
undertaken within the context of the broader
community and its values and expectations.
Management actions must engage all
stakeholders and recognise their roles and
responsibilities. Some key recommendations are
outlined below:
•
Consider the diversity of ‘values’ of alien
species to specific communities and the
broader community throughout the MurrayDarling Basin and ensure that these values are
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•
Develop appropriate community engagement
materials and processes based upon the
full range of tools, strategies and literature
that has emerged through previous resource
management activities and initiatives in
Australia and overseas (e.g. Landcare,
Cooperative Research Centres etc). These
materials and processes should also be
informed by the results of social research.
•
Raise the public profile of alien species as a
threatening process.
•
Report both failures and successes of
management actions.
5.2.5 Control and management
Some alien species such as Carp are well
established within the Basin and the workshop
acknowledged that prevention measures will
reduce the risks of new infestations but will not
always be successful. New infestations may still
occur over time. It is important that jurisdictions
in the Basin are in a position to undertake
effective control measures if eradication is not
possible. Workshop participants identified the
following priority actions related to the control of
established populations of alien fish species:
•
•
Build capacity in alien fish management across
agencies, authorities and jurisdictions. This
should include activities such as multi-state
teams, training workshops, scenario testing,
experiential learning and communitybased research.
•
Undertake monitoring to determine
success and failure against stated objectives
and targets at both the community and
scientific levels.
•
Use adaptive experimental management
to test specific questions and
management hypotheses.
•
Undertake and report bioeconomic
assessments of potential and existing
management actions to help ensure
appropriate resources necessary for
successful alien species management.
•
12
Utilise demonstration reaches under
the Native Fish Strategy as a means of
simultaneously rehabilitating fish habitat
and controlling alien species in an
integrated manner.
Develop database and GIS capacities with
connections to international databases and
experts to assist alien species management.
5.2.6 Toolbox
Workshop participants recognised the
importance of shared knowledge in relation to the
management of alien fish species. The concept of
developing a ‘toolbox’ of up-to-date management
and control techniques was widely supported. The
following actions were recommended:
•
Develop a ‘toolbox’ of management techniques
for the removal and control of alien species.
This ‘toolbox’ should be a collaborative and
cooperative effort between all jurisdictions and
be commonly available and used across
the Basin.
•
Develop new tools for control and
management of alien species and add these to
the ‘toolbox’ including:
-Chemical (e.g. poisons);
-Approvals (e.g. permits);
-Containment (e.g. exclusion screens);
-Biological (e.g. virus/genetic);
-Species vulnerabilities (ie. ‘Achilles heel’);
-Planning and modelling.
•
Place a greater investment in the development
and implementation of detection technologies.
•
Maintain the database of fish distribution
recently developed under the Native
Fish Strategy.
•
Develop a reference compendium for social
research, education and extension processes.
5.2.7 Species specific management
and research
A. Redfin perch
A.1 Management
•
Collate a species synopsis including biology,
distribution, social and economic values,
likely environmental impacts and present
management arrangements.
•
Update information on Epizootic
Haematopoietic Necrosis Virus (EHNV),
as it becomes available.
•
Ensure no stocking or translocation in
any jurisdiction.
•
Develop management options to isolate and
stop the species spreading further within the
Basin (i.e. targeted education).
•
Establish a demonstration reach to include the
control of redfin.
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A.2 Research
•
•
•
•
•
•
Investigate Redfin perch and Carp interactions
to predict likey outcomes on Redfin perch
populations if Carp are removed.
behaviour in relation to exposure to
these chemicals.
•
Investigate the tolerance of Oriental
weatherloach to desiccation and the impacts of
this on control options.
•
Clarify the taxonomy of Oriental weatherloach
in Australia.
•
Collate information on diseases
associated with Oriental weatherloach
in their native range.
•
Investigate the ability of Redfin perch to
acclimate to water temperatures outside their
normal tolerance range.
Investigate the potential use of pheromones in
the control of Oriental weatherloach.
•
Investigate the tolerances of Redfin perch to
various piscicides and their behaviour in relate
to exposure to these chemicals.
Investigate movement patterns and dispersal
mechanisms associated with
Oriental weatherloach.
•
Undertake social research with a focus on
recreational anglers in relation to use of baits
and target species.
•
Investigate the impacts of Oriental
weatherloach on native species including;
direct interactions (aggression, predation,
competition for food and space) and
habitat damage.
Investigate native species alternatives for
recreational angling.
Investigate the effects of EHNV in the wild and
continue tests on other native species in
the laboratory.
Collate information on diseases associated
with Redfin perch in their native range.
•
Investigate movement patterns and dispersal
mechanisms associated with Redfin perch.
•
Investigate the impacts of Redfin perch on
native fish species including; direct interactions
(aggression, predation, competition for food and
space) and habitat damage.
•
Model the likely response of Redfin perch
populations to thermal pollution mitigation.
•
Investigate the behaviour of Oriental
weatherloach to inform control measures.
•
Investigate the use of sterile male Redfin perch
as a control option.
•
Investigate the feeding habits of
Oriental weatherloach.
•
Undertake social research with a focus on
recreational anglers in response to the use of
baits and target species.
•
Investigate the potential use of natural
predators as a control method for Oriental
weatherloach, particularly Eel-tailed catfish.
•
Better define the social and economic values
of Redfin perch.
•
Investigate the ability of Oriental weatherloach to
acclimate to water temperatures outside their
normal tolerance range.
B. Oriental weatherloach
B.1 Management
•
Collate a species synopsis including biology,
distribution, social and economic values,
likely environmental impacts and present
management arrangements.
•
Implement targeted education/extension
program to minimise the risk of Oriental
weatherloach spreading further in the Basin.
This program should recognise that the
species is used as live bait.
•
Develop control techniques and undertake
control activities based on cost/benefit
analysis for prioritisation of actions.
B.2 Research
•
Investigate the tolerances of Oriental
weaterloach to various piscicides and their
C. Tilapia
C.1 Management
•
Undertake a targeted community education
program with an emphasis on the risks
associated with the spread of Tilapia into
the Basin. Involve recreational fishers
in the program.
•
Finalise the rapid response process
being developed in Queensland and develop
into a Basin-wide response.
•
Involve southern states in Queensland
activities to build capacity in
Tilapia management.
•
Investigate the community attitudes to the
species, particularly why some anglers
appear to support a Tilapia fishery in north
Queensland rather than a native species
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13
fishery. Determine methods to reverse this
perceived trend.
C.2 Research
•
Investigate the ability of Tilapia to acclimate to
temperatures outside their normal tolerance
range particularly in relation to lower
temperatures that would be experienced in the
Murray- Darling Basin.
•
Collate information on diseases associated
with Tilapia in their native range.
•
Clarify the taxonomy of Tilapia in Queensland
including the occurrence of hybrids.
•
Investigate the tolerances of Tilapia to various
piscicides and their behaviour in relation to
exposure to these chemicals.
•
Investigate methods for early detection of
Tilapia in waterways and wetlands.
•
Investigate methods of attracting Tilapia
(including acoustic methods) to assist in
control measures.
•
Investigate movement patterns and dispersal
mechanisms associated with Tilapia.
•
Investigate the impacts of Tilapia on
native species including direct interactions
(aggression, predation, competition for food
and space) and habitat damage.
•
Undertake social research with a focus on
recreational anglers in relation to use of baits
and target species.
overseas literature. Liaison with hobbyists
should also be undertaken.
•
Develop a GIS database for alien species
that identifies ‘at risk’ catchments (high
value, high probability of infestation, etc) and
incorporates environmental classification
tools (systematic conservation planning tools).
•
Investigate dispersion pathways and define
vectors (quantify risk) for high risk alien
species. Investigate the use of molecular
methods to determine multiple introductions.
•
Quantify impacts of alien species with priority
being given to established species. Research
should include before and after invasion
studies; impacts on individual native species;
impacts on ecosystems; thresholds for
impacts and density dependency of impacts.
•
Investigate techniques to assist with early
detection of alien species.
•
Establish adaptive experimental management
sites to test hypotheses. These should
include goals, strategies and the evaluation
of alien species management verses other
rehabilitation practices.
•
Undertake risk assessments of alien species
management practices and link results to
modelling pathways.
•
Undertake modelling of various management
scenarios, population dynamics, feasibility/
likely results and extent of spread.
•
Undertake bioeconomic investigations of alien
species management practices including
cost/benefit analysis and impacts of alien
species on ecosystem services.
•
Investigate the potential ecological
consequences of successful removal of
different alien species including the likelihood
of recovery, thresholds for effects and density
dependency. Information on other vertebrate
pests should be examined.
•
Develop decision frameworks for alien
species management and ensure that these
are integrated with other vertebrate pest
species management.
•
Undertake a critical assessment of past
alien species management techniques and
initiatives, both national and international.
•
Target multi-disciplinary knowledge exchange.
5.2.8 General Research Recommendations
•
•
•
14
Investigate technical control options to
evaluate the best techniques for particular
alien species and link these to modelling
of potential management strategies.
Investigations should include policy research,
biological control (genetics, disease),
chemical control (pheromones, piscicides,
disruptors) and mechanical controls (screens,
removal, traps).
Undertake social research to investigate
the drivers of community attitudes and
how these attitudes can be changed where
necessary. This research should encompass
all stakeholders including the community,
governments and institutions, legislators,
decision-makers, and politicians.
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
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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
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15
Alien species in the context of
the Native Fish Strategy
Jim Barrett
Murray-Darling Basin Commission, GPO Box 409, Canberra act 2601
Abstract
The Native Fish Strategy for the Murray-Darling
Basin 2003–2013 lists alien species as one of
eight major threats to the decimated native
fish populations of the Murray-Darling Basin.
To achieve its 50-year goal of restoring native
fish populations to at least 60% of former preEuropean levels, the Strategy recognises that all
threats must be addressed, and in a sustained
and integrated manner. In addressing the alien
fish problem, the Strategy’s immediate tasks
are to: limit the further spread of alien species;
prevent the establishment of more alien species;
incorporate alien species management into
the broader framework of river rehabilitation;
employ demonstration reaches as models; apply
an integrated package of control techniques to
problem sites and monitor the results, with the
focus on reducing the damage caused by alien
species rather than on their density; support
the development of new control technologies;
undertake risk assessments for alien fish species
currently in captivity; and educate and engage the
community in alien fish problems
and their management.
Background
In May 2003, the MDB Ministerial Council
approved a ten-year Native Fish Strategy (NFS)
for the Murray-Darling Basin 2003-2013 (MurrayDarling Basin Commission 2004). The 2003–2013
Strategy is the first stage of a 50-year plan to
rehabilitate native fish populations throughout
the Basin by addressing key threats and
providing direction for investment in on-ground
management activities and research.
Alien fish are recognized as a significant threat to
16
Australia’s freshwater ecosystems. The NFS lists
them as one of eight key threats to native fish in
the Basin, where 12 alien species are present.
Hence, of the 13 objectives of the NFS, one
relates directly to alien species, namely to
‘Control and manage alien fish species’. Another
two objectives are relevant in that the improved
management of alien fish will assist to:
•
‘Protect native fish from threats of disease and
parasites’; and
•
‘Protect native fish from the adverse effects of
translocation and stocking’.
In addition, ‘Controlling alien fish species’ is one
of the six driving actions of the NFS.
The contribution of alien species management
to the NFS is important to its overall goal of
rehabilitating native fish to 60% of pre-European
population levels in 50 years (MDBC 2004).
Nevertheless, it should not be regarded as
more important than the other key threatening
processes. A scientific panel—established to
develop a conceptual model, or models, to
inform NFS deliberations and future investment
decisions—reported that without addressing
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.
The NFS advocates an integrated approach
to alien species management, involving the
simultaneous application of a package of control
techniques. Currently, singular techniques for
controlling carp include capture and removal
(e.g. commercial fishing, carp separation cages),
chemicals (e.g. rotenone—with limitations on its
use), environmental manipulation (e.g. lowering
wetland levels after a breeding event), exclusion
devices (e.g. screens) and biological control (e.g.
genetic modification and viral control agents).
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In terms of broad-scale river rehabilitation, alien
species management would be expected to be
a component of most large projects, including
demonstration reaches. Demonstration reaches
are large-scale river reaches in which multiple
fish habitat management interventions are
applied in order to increase awareness and
support for fish conservation (Barrett & Ansell
2004). The aim of the demonstration reach is
not to restore fish habitat to original or pristine
condition—a common and often unrealistic
expectation of stream rehabilitation programs.
Instead, the demonstration reach concept
recognises the need to address all threats
to native fish, not just those most obvious or
convenient, whilst simultaneously showcasing the
benefits of river rehabilitation for native fish to
the community.
Overall river rehabilitation also extends to the
declaration of protected areas for native fish such
as habitat management areas (as defined in the
NFS) and “river parks” (Phillips and Butcher
2005). There may be a need for an aim to exclude
alien species in these protected areas rather than
managing their damage.
Actions required under the
Native Fish Strategy
The NFS sets out several prescriptions that
guide effort and investment in the control of
alien species. In terms of management, the
Strategy dictates that the Murray-Darling Basin
Commission (MDBC):
(i) Implement the National Management
Strategy for Carp Control, including regional
carp management plans
It is now known that controlling the damage
caused by carp is a complex management issue.
Carp impact is closely linked to many other
factors that have degraded Australia’s waterways
and hence the quality of native fish habitat (CCCG
2000a). These factors include salinity, high
nutrient loads leading to algal blooms, excessive
water extraction and construction of dams and
weirs that are a barrier to the movement of many
native fish (Braysher and Barrett 2000).
To help manage this issue, a package of
documents has been prepared and released.
These are:
•
The National Management Strategy for Carp
Control (NMSCC), produced by the Carp Control
Coordinating Group (CCCG 2000a);
•
Managing the Impacts of Carp, produced by the
Bureau of Rural Sciences under the National
Feral Animal Control Program
(Koehn et al. 2000);
•
Ranking Areas for Action: A Guide for Carp
Management Groups (Braysher & Barrett
2000); and
•
Future Directions for Research into Carp,
produced by the CCCG (CCCG 2000b).
The Bureau of Rural Sciences publication,
Managing the Impacts of Carp, outlines a strategic
approach to carp management and provides a
detailed discussion of carp damage and control
techniques. The National Management Strategy
For Carp Control provides the national framework
for progressing carp management. The third
document, Ranking Areas for Action: A Guide
for Carp Management Groups (guidelines) is a
practical step-by-step tool to assist local groups
plan and implement the NMS at the catchment/
sub-catchment level. The package of documents
is unique. Together they take a major resource
management issue from the policy development
stage through to practical ways to address it at
the local level.
(ii) Resolve inconsistencies in legislation
and policy
As with many regulatory issues, each State and
Territory has fish and fisheries management
legislation (see Higham et al.
pg 40 this publication) that deals with the raft of
issues relating to alien freshwater fish species,
including size and bag limits, importation,
stocking and translocation. The provisions for
dealing with these issues vary significantly
between jurisdictions.
(iii) Develop reporting and rapid response
systems for new alien species
It is now common practice to have a contingency
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 MurrayDarling Basin were received in 2000, the MDBC
organised a facilitated workshop in Toowoomba
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17
to discuss a rapid response system for new alien
species. Consequently, a rapid response system is
now being developed for invasive freshwater fish
in Australia. The project will review national and
international practice in response to new outbreaks
of alien fish and examine the success or otherwise
of attempts to eradicate alien fish in Australia.
Other outcomes of the project will include:
•
documentation of response plans for new
alien fish incursions for all Australian States/
Territories;
•
review of potential control and or containment
methods;
•
adoption of a consistent approach to new alien
fish incursions in Australia; and
•
identification of opportunities to field test the
response capability.
(iv) Encourage an integrated pest
management approach
The notion of integrated pest management (IPM)
involves the simultaneous application of a range of
control techniques, applied strategically and as an
integrated package in order to achieve a significant
and measurable reduction in the damage caused
by a pest species. IPM is about:
•
a focus on reduction of the damage done to the
ecosystem rather than simply on the density or
numbers of the pest species causing
that damage;
•
using a combination of techniques at the same
time (more or less);
•
monitoring the response of the system to the
use of these techniques;
•
acknowledging that the relative importance
or weight of each technique varies
in each situation;
•
adapting and refining the targets over time.
In terms of research and investigation, the
Strategy recommends concentrating effort in the
following areas:
(v) Identifying key regions, such as
recruitment areas, and dispersal patterns
In 2002 the Arthur Rylah Institute (ARI) identified
that the Barmah-Millewa floodplain is a point
source for carp recruitment (Stuart & Jones 2002).
ARI found that the majority of adult carp occupied
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
to consider dispersal, especially of young-ofyear, when designing fishways (i.e. to include
carp separation cages) and the control of critical
access points for carp (both adults and juveniles)
to and from the Barmah-Millewa floodplain.
With funding from the MDBC, the Invasive Animal
Cooperative Research Centre is attempting to
determine the location of hot spots for carp
recruitment. It appears that carp spawning is
highly habitat specific and most carp breeding
occurs in a limited number of areas. Potentially,
as few as five areas in New South Wales account
for the vast bulk of carp recruitment (D. Gilligan
pers. comm 2006).
(vi) Identifying areas free of alien species
One of the key goals of the National Management
Strategy for Carp Control is to prevent the further
spread of carp. This includes the need to identify
environmentally valuable areas where there is a
risk that carp will be introduced or re-introduced,
and to promote community understanding and
support for controls on the movement of live
carp. Keeping areas free of alien species is costeffective in terms of conservation management,
but requires public support and vigilance.
(vii) Identifying potential new alien species
and their likely impacts
While the Environment Protection and Biodiversity
Conservation Act 1999 includes a list of about
500 species of alien freshwater fish that
are permitted imports to Australia (primarily for
the aquarium trade), changes in legislation over
time, inconsistencies in legislation and outright
smuggling mean the exact number of species
actually in Australia is not known (but suspected
to be in the thousands) (see other papers in this
publication). Because many of these species have
not been assessed through current import risk
assessment process, the potential impact should
they escape or be released is not known. An
agreed national noxious species list has recently
been adopted, and a priority list developed of
species that need further assessment (Natural
Resources Ministerial Council 2006). This will be
accompanied by public education and awareness
campaigns to address issues related to species
that present a potential significant risk that are
already in the country.
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(viii) Addressing key knowledge gaps
There are major gaps in knowledge on carp and
other alien fish. Areas of research needed include
biology, distribution and damage to native fish
and the environment, effective control strategies,
commercial use and disease. For carp, these
gaps are documented in the MDBC publication
Future Directions for Research into Carp
(CCCG 2000b).
(ix) Investigating the application of
biotechnology
The MDBC has already invested over $4M
in the ‘daughterless carp’ concept, and has
committed another $5M over the next few years.
Daughterless carp technology can be described
as ‘a genetic construct, using species-specific
genes, that is inheritable and biases offspring sex
ratios towards males’. In theory, to instil into wild
carp a heritable bias towards males will inevitably
distort sex ratios, leading to reproductive
failure and population crashes. Nonetheless,
daughterless carp technology should not be seen
as a ‘silver bullet’, rather as part of a package of
integrated control.
Finally, in terms of community engagement, the
Strategy emphasises:
(x) The need to encourage actions
undertaken by communities on controlling
alien species
Community groups and catchment management
organisations are becoming increasingly active
in alien species control, particularly in wetlands.
Nevertheless, a greater emphasis needs to
be placed on education about some alien
species such as Eastern gambusia and Oriental
weatherloach, which are often mistakenly
regarded as benign (Driver et al. 2005).
Species such as carp not only breed in wetlands,
but also quickly out-compete native fish (Koehn
et al. 2000). The fact that they are the first to
enter and the last to leave wetlands following
connection to the main channel (Driver et al.
2005) offers potential for effective community
management solutions.
carp in Australian waterways. The Task Force
had representation from Local Government,
researchers, agencies, community, anglers,
commercial fishers, and catchment
management. The Task Force supported a
range of education, community engagement,
research, business, and wetland initiatives. In
2002, the Task Force changed its name
to the National Carp & Pest Fish Task Force
to reflect increasing concern over the 11
other alien fish threatening the Murray-Darling
Basin. The Task Force developed an action plan
to ensure community participation and has since
been implementing the plan, much of it through
participation in the Native Fish Strategy and the
work of the Pest Animals & Invasive Animals
Cooperative Research Centres.
(xii) Carp-a-thons
In the Logan-Albert system just outside the
Basin in south-east Queensland, a community
group, ‘Carp Busters’, has been mobilising
the local community to remove carp through
organised recreational angling events. Whilst
it is doubtful whether such events have any
benefit in terms of reduction in carp numbers,
especially considering that a female carp can
produce up to 7 million eggs (Koehn et al.
2000), these events provide a useful method for
developing community awareness of alien fish
and encouraging them to become involved in
their management.
(xiii) The role of commercial fishing
Commercial carp fishing occurs in Victoria,
South Australia and (irregularly) in New South
Wales (such as at Moira Lake in the BarmahMillewa Forest). Freshwater commercial fishing
is prohibited in the MDB in Queensland. While
commercial fishing is not an effective means of
control in itself, it can be a valuable component
of an integrated pest management program. For
example, at times it may be useful as a shortterm management tool while techniques for
wider control are being developed.
(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
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19
Concluding remarks
The NFS recognises that the response of native
fish populations to various kinds of rehabilitation,
including alien species management, is
cumulative and will take time. It is clear that
addressing just a few of the threatening processes
will produce only modest results. In order to
achieve the Strategy’s goal of 60% reinstatement
of native fish populations in 50 years (MDBC 2004),
the major contributing threats need to be dealt
with concurrently, in an integrated way.
The concept of demonstration reaches is gaining
momentum as a pragmatic mechanism for
effecting river rehabilitation across significant
stretches of degraded but restorable river
systems. Alien species control is one of the
tangible actions that can be undertaken in an
integrated way in a demonstration reach.
In terms of carp, it is important to implement the
National Management Strategy for Carp Control
and Ranking Areas for Action: A Guide for Carp
Management Groups. Although there are no silver
bullets, encouraging new breakthroughs include
the continued refinement of carp separation
cages, the development of a rapid response
system for new outbreaks and the identification of
recruitment ‘hotspots’. ‘Blue sky‘ research such as
daughterless carp technology and Koi herpes virus
may eventually significantly augment the armoury
of techniques available to effectively manage
this species.
It is crucial to involve the community in alien
species management. Cooperation between
management agencies, community groups, and
sectors such as recreational fishing, commercial
fishing and tourism, is essential and partnerships
need to be fostered through locally developed and
owned management plans. Improved community
awareness and understanding of alien species
issues can be achieved by targeted publicity on:
the biology and damage caused by such species;
national, regional and local strategies and control
programs; and the impacts of alien species on
community assets and resources, such as water and
fisheries, in the context of other factors that impact
on them. For their part, communities (through
groups such as the National Carp and Pest Fish
Task Force) can encourage local stewardship of the
aquatic environment and coordinate local group
development and action. They can also improve the
quality and objectivity of education used in raising
community awareness of alien species and what can
be done to manage them.
20
In summary, the way forward for alien fish
management in the MDB involves:
•
limiting the further spread of alien species,
whether that spread is by accidental release,
discarding of unwanted fish, or deliberate
introduction of such fish to new waters as a
source of table fish, bait and/or recreation;
•
preventing the introduction of new alien
species, which necessitates tighter import
restrictions, rapid reporting and response, and
community education;
•
incorporating alien species management into
the broader framework of river rehabilitation
as a normal management intervention in
rehabilitation programs, including those for
demonstration reaches;
•
applying an integrated package of
management techniques to a number of
problem areas or hotspots, and measuring the
results, with the focus on reducing the damage
caused by alien species rather than on
their density;
•
cautiously supporting the development of new
control technologies on the basis of: (a) their
potential to usefully augment the current
range of techniques; (b) their likely social,
political, economic and logistical acceptability;
(c) their progress at ‘stop-go’ points in their
developmental phase; (d) the availability of
funding; and (e) continued favourable review
against (a) and (b);
•
assessing the risk of establishment in the wild
of alien fish species currently in captivity in
Australia, or likely to be proposed for import,
and their potential environmental, economic
and social impacts;
•
educating the public on alien species
and their impacts and engaging them in
on-ground management.
References
Barrett, J. 2001. Australia’s National Management
Strategy for Carp Control. In: Managing Invasive
Freshwater Fish in New Zealand. Proceedings of a
workshop hosted by Department of Conservation,
10–12 May 2001, Hamilton. Department of
Conservation, Hamilton, New Zealand.
Barrett, J. and Ansell, D. 2005. Demonstration
reaches for native fish: moving from theory to
practice. In I. D. Rutherford, I. Wiszniewski, M. J.
Askey-Doran & R. Glazik (Eds.) Proceedings of the 4th
Australian Stream Management Conference: linking
rivers to landscapes. (pp. 59-67).
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Braysher, M. and Barrett, J. 2000. Ranking Areas for
Action: A Guide for Carp Management Groups. MurrayDarling 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.
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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
1
Environment & Recreation (Research & Monitoring), Department of Territory & Municipal Services,
PO Box 144, Lyneham, ACT, 2602. [email protected]
Freshwater Ecology, Arthur Rylah Institute for Environmental Research,
DSE, 123 Brown Street, Heidelberg VIC 3084. [email protected]
2
3
Centre for Fish & Fisheries Research, Murdoch University,
South St Murdoch, Western Australia, 6150. [email protected]
4
Fisheries and Aquaculture Development, Department of Primary Industries and Fisheries,
GPO Box 46, Brisbane, Qld 4001. [email protected]
Current address: Murray-Darling Basin Commission, GPO Box 409, Canberra ACT 2601.
5
Abstract
This paper addresses various ecological impacts
and knowledge gaps surrounding two introduced
fish species that are currently entrenched within
the Murray-Darling Basin, namely Redfin perch
(Perca fluviatilis) and Oriental weatherloach
(Misgurnus anguillicaudatus), and a third species,
the Mozambique moothbrooder or Tilapia
(Oreochromis mossambicus), that is likely to
invade the system in the near future. The main
vectors of dispersion throughout the catchment
are identified as being either through illegal
stocking, as escapees from ornamental or farm
ponds, as bait bucket introductions or through
water diversion. For sound management of each
of the species, adequate resources need to be
directed towards filling voids in our knowledge
of the species within the Murray-Darling Basin.
Resources should be directed at acquiring an
understanding of habitat and environmental
requirements, species ranges, general biology
and ecology, interactions with native species,
disease risk and social reasons behind
deliberate releases.
22
Introduction
Why Redfin perch, Mozambique
mouthbrooder (Tilapia) and Oriental
weatherloach?
Alien species and their associated impacts are
considered to be a key threat to native fish not
only in the Murray-Darling Basin (MDB) (MDBC
2004), but also nationally (e.g. Arthington &
McKenzie 1997, Koehn & Mackenzie 2004,
Lintermans 2004, Morgan et al. 2004) and
internationally (Fuller et al. 1999; Moyle & Light
1996; Rahel 2002), and the management of alien
species may be one of the biggest challenges
that conservation biologists will face in the
coming decades (Allendorf & Lundquist 2003).
The Australian freshwater fish fauna contains a
high proportion of alien species (~34 out of ~240
fish species), with 12 of 53 (23%) freshwater
fish species in the MDB considered alien (11
exotic, 2 translocated) (Lintermans in press).
Consideration of the issues surrounding all of
the alien species in the MDB was not deemed
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
E m e r g i n g I ss u e s i n A l i e n F i s h Ma n ag e m e n t i n t h e M u r r ay Da r l i n g B a s i n – W o r k s h op , 3 0 - 3 1 May 2 0 0 6
Figure 1. Redfin perch (Perca fluviatilis). Photograph: G. Schmida
these three species would provide some context
to the wider issues of alien fish management
in the MDB. Redfin perch is a moderate sized,
long-established, widely distributed species
in the MDB, with a range of ecological issues
and public values/perceptions (ecological
impact vs. value as recreational species). The
Mozambique mouthbrooder is also a moderate
sized species whose range is expanding rapidly
on the northern edge of the MDB and is likely
to become established in the future. As an
invasive species it is known to cause ecological
impacts but is also valued as a recreational and
commercial species. Oriental weatherloach on
the other hand is a small, recent invader of the
MDB and has its origins in the aquarium-trade
(the source of all recent invasions) (Lintermans
2004). While its range is expanding within the
MDB, its precise distribution is poorly known
due to its cryptic behaviour and its largely
unknown ecological impacts are hindered by a
lack of research.
Overview of the
Ecology of the species
Redfin perch (Perca fluviatilis)
Distribution
Redfin perch (Figure 1) attain a maximum size
of 600 mm total length (TL) (commonly 300
mm, 1-2 kg) (Cadwallader & Backhouse 1983).
The species was introduced to Australia from
England between 1858 and 1862 (to Tasmania)
and 1861 (Victoria) (Clements 1988; Morgan et
al. 2005; Weatherley 1977). The species is now
widely distributed in the lower to mid reaches of
the MDB (South Australia, Victoria, New South
Wales, Australian Capital Territory) and is also
present in southern Western Australia (Morgan
et al. 2002, 2004) and Tasmania (McDowall 1996).
It is not present in Queensland or northwestern
NSW and its distribution is partly limited by high
water temperatures (an upper thermal limit of
30–31ºC) (Weatherley 1963, 1977). Despite its
known impacts on native fish and crustaceans
(see below), Redfin perch is a valued target for
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23
recreational fishers, particularly in Victoria, and is
still being actively spread (illegally) in the MDB by
anglers (Lintermans unpubl. Data).
Ecology
Redfin perch is a schooling species, particularly
as juveniles, and occurs in a wide variety of
habitats, but prefer still or slow–flowing waters,
usually with abundant aquatic vegetation.
It is a voracious carnivore, with the diet of
small fish (<100 mm TL) consisting mainly
of zooplankton & dipteran pupae, with larger
aquatic invertebrates (odonatans, decapod
crustaceans) becoming more dominant in midsize fish (100-200 mm TL); with Redfin perch
> 200 mm TL consuming predominantly fish,
crayfish and odonatan larvae (Morgan et al. 2002).
Spawning occurs in late winter‑early spring (July
to September), when water temps reach 11–12°C.
Fecundity is high (up to 45 000 eggs/kg of body
weight), with up to 200 000 eggs/female recorded
(see Morgan et al. 2005).
Impacts
Redfin perch are known piscivores but also
prey heavily on freshwater crayfishes. Within
Australia they have been documented as
predating on a large number of native fishes
including Carp gudgeons (Hypseleotris spp.),
Murray cod (Maccullochella peelii peelii), Golden
perch (Macquaria ambigua), Western pygmy
perch (Edelia vittata), Southern pygmy perch
(Nannoperca australis), Yarra pygmy perch (N.
obscura), Ewens pygmy perch (N. variegata),
Nightfish (Bostockia porosa), Mountain galaxias
(Galaxias olidus), Flatheaded galaxias (G.
rostratus),Obscure galaxias (Galaxias sp.1),
Common galaxias (Galaxias maculatus), Eastern
little galaxias (Galaxiella pusilla), River blackfish
(Gadopsis marmoratus), Flatheaded gudgeon
(Philypnodon grandiceps), Dwarf flatheaded
gudgeon (Philypnodon sp.), Australian smelt
(Retropinna semoni), Murray-Darling rainbowfish
(Melanotaenia fluviatilis) and a number of
crayfish species including Marron (Cherax
cainii), Gilgies (Cherax quinquecarinatus), Yabby
(Cherax destructor), Bush yabbies (Geocharax
spp.) and possibly the threatened Swamp yabby
(Gramastacus insolitus) (Hutchison 1991; Pen &
Potter 1992; Hutchison & Armstrong 1993; Pen et
al. 1993; Morgan et al. 2002, 2005; Hammer 2004;
Weatherley 1963, 1977; Raadik &
Backhouse in press).
24
Either Redfin perch, Carp (Cyprinus carpio) or
Goldfish (Carassius auratus) is suspected of
introducing the parasitic copepod Lernaea to
Australia (Langdon 1989a), and Redfin perch
is the main host for Epizootic Haematopoietic
Necrosis Virus (EHNV), which is unique to
Australia. First isolated in 1985 from Redfin
perch, this virus is characterised by sudden
high mortalities of fish (Langdon et al. 1986,
Langdon & Humphrey 1987). Experimental
work has demonstrated that Macquarie
perch (Macquaria australasica), Silver perch
(Bidyanus bidyanus), and Mountain galaxias
are among several native species extremely
susceptible to the disease, as well as the alien
species Rainbow trout (Oncorhynchus mykiss)
and Eastern gambusia (Gambusia holbrooki)
(Langdon 1989b). Furthermore, Murray cod are
capable of carrying the disease and Macquarie
perch (Macquaria australisica) exposed to
water that had held infected Redfin perch
demonstrated 100 % mortality within 6-11 days
(Langdon 1989b). The virus is very resistant
to desiccation, with dried samples retaining
their infectivity after 113 days, but not at 200
days (Langdon 1989b). The virus has now been
recorded in South Australia, New South Wales,
the Australian Capital Territory and Victoria
(Whittington et al. 1996), and once EHNV is in a
waterbody, it is considered impossible
to eradicate.
Mozambique mouthbrooder or Tilapia
(Oreochromis mossambicus)
Distribution
Two species in Australia are commonly
referred to as Tilapia: the Black mangrove
cichlid (Tilapia mariae), native to the coastal
rivers of west Africa, and the Mozambique
mouth-brooder (Oreochromis mossambicus),
native to the eastern coastal rivers of southern
Africa from the Zambezi River south to the
Eastern Cape (Skelton 2001). Tilapia mariae is
generally restricted to latitudes north of the
Mulgrave River in Queensland (Anon. 2001), as
it is intolerant of colder water temperatures,
and so is not considered a threat to the MDB.
A population of T. mariae is present in Victoria,
though restricted to an artificially warm habitat,
receiving thermally polluted warm water
discharged from a power station (Cadwallader
et al. 1980). Oreochromis mossambicus (Figure 2)
is widespread in northern Queensland , around
Brisbane in south east Queensland and within
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Figure 2. Mozambique mouthbrooder (Oreochromis mossambicus) from the Lyndon River in Western Australia.
Photograph: D. Morgan.
parts of the Indian Ocean (Pilbara) Drainage
Division of Western Australia where it is currently
restricted to the Chapman, Gascoyne, Minilya and
Lyndon rivers (Arthington et al. 1984; Arthington
1986; Arthington & Blühdorn 1994; Morgan et al.
2004). Due to the very close geographic proximity
of the species to the MDB (where it is within 100s
of metres of the Basin in headwater tributaries
of the Burnett River catchment) it is likely to be a
future invader of at least the northern reaches of
the system.
Ecology
The Mozambique mouthbrooder is a moderatesized fish that attains a maximum total length of
approximately 500 mm and 3 kg (Skelton 2001),
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
(temperature, salinity, DO) and has flexible
habitat requirements. The species survives in
temperatures between 8-42 °C, is active above
16 °C and breeds at temperatures of 20-24 °C
(Mackenzie et al. 2001, Skelton 2001). While
naturally found in closed estuaries and coastal
reaches of rivers, as well as inland regions in
south-eastern Africa (Skelton 2001), it has been
recorded in WA at salinities up to 95ppt in the
Lyndon River and found near the mouth of the
Chapman River estuary (Morgan et al. 2004).
Growth of populations and individuals is often
rapid. For example, from 6-8 fish released into
an ornamental pond in Cairns 18 months prior
to rotenone treatment, 12.5 ton of fish
were removed!
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25
Figure 3. Oriental weatherloach (Misgurnus anguillicaudatus). Photograph: G. Schmida.
Impacts
Aspects of their population ecology, such as
mouth brooding, and ability to breed all year
round allow for very rapid population growth
and wide tolerance to varying environmental
regimes allows the species to dominate a fish
fauna in abundance and biomass very quickly and
makes them a highly effective invader of rivers
(including estuaries), lakes and wetlands. This
also has ramifications for recreational fisheries
where the species may dominate more desirable
recreational species. Both male and female
individuals are aggressive during the spawning
season; nests are built and occur in high densities
e.g. ~80% of shallows were covered in nests in the
Gascoyne River (WA) (Morgan et al. 2004). Males
defend the nests and are aggressive towards
other fish in the nesting area. Such 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. The species
has been reported elsewhere to kill aquatic
26
macrophytes while feeding on periphyton, and
they may eliminate submerged and emergent
macrophytes by grazing or by uprooting plants
(Lahser 1967). There is little data available on
competition for food between Mozambique
mouthbrooder and Australian native fish species,
however the diet of juvenile O. mossambicus in
the Chapman River (WA) and mature fish in the
Gascoyne River was dominated by detritus, while
some aquatic insects are also taken (Maddern
2003; Morgan et al. 2004). The species’ success
is also attributed to being able to utilise detritus,
which in most systems dominates the substrate.
There is also some potential for this species
to spread diseases and parasites to native fish
species.
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Oriental weatherloach
(Misgurnus anguillicaudatus)
A detailed review of the taxonomy, biology and
ecology of the Oriental weatherloach (Figure 3)
in its native range, and in Australia, has been
recently been undertaken by Koster et al. (2002).
Which weatherloach in Australia?
Misgurnus loaches are highly variable in
morphology and coloration with in excess of 30
species described. Approximately four species
are currently recognised as valid, but there is
disagreement between researchers (Koster et al.
2002). The four valid species are:
- M. anguillicaudatus
- M. cestoideus
- M. bipartitus
- M. mizolepis
Weatherloach have been introduced to Australia
via the aquarium trade with approximately
50,000 fish imported annually in the early 1980s
before importation was banned in 1986. The
taxonomic keys are poor, and potentially all four
Misgurnus species were imported. It is currently
assumed that the majority of imports were of M.
anguillicaudatus, and that this is the only species
established in Australia (Koster et al. 2002).
Distribution
Oriental weatherloach is a small, elongate
fish with a maximum length 200–250 mm, but
usually is less than 180 mm TL in Australia
(Figure 3). It has established populations in a
number of countries outside its natural range,
including the USA, Germany, Philippines, Palau
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
known from the Yarra River in Victoria by 1984
(Allen 1984). Populations are now known from
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).
Ecology
In Australia, Oriental weatherloach is a bottomdwelling, cryptic species with no known migratory
movements. Data from Japan suggests that a
proportion of adults move from streams into
paddy fields to spawn, with the adults and
juveniles subsequently returning to streams
(Tanaka 1999). Weatherloach is a habitat
generalist, occurring in still lakes or ponds,
drains, rivers, creeks, and billabongs. Habitats
can be vegetated or un-vegetated, permanent
or temporary, with substrates including cobble,
pebble, gravel, sand, mud and detritus. Their
habitats range from clear, upland, cobblebottomed streams (Cotter River, ACT) to lowland
turbid rivers (Murray River) and billabongs, and
habitats can be natural, modified, or degraded.
They can often be found in sandy or silty habitats
with accumulations of leaf litter, organic debris or
root mats, usually in backwater or
low-flow areas.
Oriental weatherloach is less active during cooler
periods, is tolerant of poor water quality and
withstands very low levels of dissolved oxygen,
and are known to hibernate and aestivate,
burrowing into the sediment. They are capable
of surviving for lengthy periods without free
water, and are often excavated from tunnels at
depth from the bottom of dry dams, billabongs,
irrigation channels, creeks and drainage lines,
etc. It is eurythermic, commonly recorded from
waters with temperatures ranging from 2 to
30ºC, and have been recorded from thermal
springs at up to 42ºC. The species is omnivorous,
with the diet containing aquatic invertebrates,
microcrustaceans, molluscs, gastropods and
some algae and plant material. It feeds by using
Figure 4. Known occurrences of Oriental weatherloach
in Australia to 2003. Further information on expansion of
the distributional range over time is in Koster et al. 2002.
&.-%"'%%(
%
@^adbZigZh
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C
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27
a combination of chemical and tactile cues and has
five pairs of barbels around the mouth to locate
food. Oriental weatherloach is a multiple spawner;
females shed from 4000–8000 small, demersal
and adhesive eggs per spawning, usually laid
on aquatic vegetation or on mud between plant
roots. Spawning occurs from spring to summer,
when water temperatures are between 20–30ºC
(with 25ºC optimal). Males mature at 1 yr (110 mm
TL) and females mature at 1-2 yrs (125 mm TL)
(Lintermans & Burchmore 1996; Koster et al. 2002;
Raadik et al. 2005).
Impacts
Oriental weatherloach is an effective invader of
flowing and still–water habitats. Specific ecological
impacts on native flora and fauna by this species
in Australia are currently unknown, though the
apparent exclusion of the native fish Mountain
galaxias has been noted. Mesocosm experiments
have also demonstrated significant reductions
in aquatic invertebrate biomass and diversity
at Oriental weatherloach densities of 4.3 fish/
m2. The same experiments also demonstrated
elevated ammonia, nitrogen and turbidity levels
at fish densities of 4.3 fish/m2. The impacts of
weatherloach on nitrogen and turbidity levels were
similar to those reported for the introduced Carp
(Cyprinus carpio) (Keller & Lake in press). They have
also been found to possess a number of parasites
not previously recorded from Australia (Dove &
Ernst 1998), and whilst most parasites are host
specific, others such as the Asian Fish Tapeworm
(Bothriocephalus acheilognathi) have been recorded
from more than 100 species worldwide (SalgadoMaldonado & Pineda-López 2003) including
Australian native fish (Dove et al. 1997).
Due to their high population abundance in many
areas, additional specific ecological impacts,
currently unsubstantiated due to lack of research,
are proposed:
•
direct predation on native fish, and possibly
frogs eggs and tadpoles;
•
competition for food and space with native
species, particularly in drying habitats;
•
predation on larval/juvenile fish.
Due to their high abundance in billabong habitats,
Oriental weatherloach has also caused minor
economic loss by blocking irrigation pump inlets.
Dispersal of
Introduced Fishes
Lintermans (2004) identified 12 major vectors for
human-assisted dispersal of alien freshwater fish
in Australia, of which 10 are potentially relevant
to the three fish species considered here (Table
1). Dispersal via deliberate legal stocking is not
conducted for Tilapia, Redfin perch or Oriental
weatherloach, and the spread via contaminated
ballast water is also considered unlikely, so need
not be further considered. However, each has
been released through non-sanctioned releases
through either illegal stocking, and potentially
through bait bucket introductions, as escapees
from ornamental or farm ponds or water
diversions. Management of vectors is an important
issue that must be addressed as a high priority if
the spread of these species is to be contained or
managed. It must also be recognised that these
dispersal vectors are not independent, and the
behavioural drivers behind the vectors are varied,
Table 1. Vectors for dispersal of alien fish in Australia, and whether they apply to Redfin perch, Tilapia and Oriental
weatherloach (proposed major vectors highlighted with double tick marks).
Vector
Redfin
Tilapia
Weatherloach
Contaminant of fish stocking
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
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poorly understood, and will need significant
input from the social sciences if mitigation is to
be effective. For example, Redfin perch in the
Canberra region were legally stocked in the 1950s,
subsequently illegally stocked into ponds and farm
dams, from where they have escaped and invaded
the majority of lowland streams (Lintermans
et al. 1990).
•
How do we control vectors for dispersal of this
species (still a popular recreational species in
some areas)?
•
What are the feasible control options for
this species?
•
Are there potential breeding or recruitment
‘hotspots’ or conditions which could be
targeted to reduce abundance?
Knowledge gaps
Mozambique mouthbrooder (Tilapia)
In most cases and particularly within the MDB
the impacts of the three species are largely
speculative and unquantified. However, the
application of the precautionary principle
indicates the need to control the species even
though complete knowledge of the impacts
is lacking.
If the impacts of these three alien fish species
are to be managed appropriately, and adequate
resources devoted to such management, the
following significant knowledge gaps need to be
addressed. Some knowledge gaps are common
across all three species, whilst others are
species specific.
Redfin perch
Redfin perch is a long-established alien species
whose impacts on native species are not well
known. Its value as a recreational fishing target in
some areas has deflected attention away from its
detrimental impacts. Significant knowledge
gaps include:
•
Current distribution and abundance within
the Basin.
•
Potential differential impacts in lotic vs
lentic waters.
•
Predation effectiveness (particular life-history
stages, particular native species,
or opportunistic)
•
Potential interaction between the impacts
from Redfin perch and with climate variability
(i.e. do droughts exacerbate predation impact
of Redfin by concentrating native species in
refuges or impoundments?)
•
What are the effects of EHN Virus in the
wild (e.g. it is known that Macquarie perch
populations are still surviving in catchments
where the virus has been confirmed)?
•
Are there impacts of Redfin perch on native
fish stocking programs (impacts on trout
stocking programs are known but little is
known of the threat to native fish stocking)
The Mozambique mouthbrooder is not yet
established in the Basin, but the Basin is
vulnerable to translocations from nearby coastal
drainages in Queensland. Key questions that need
to be addressed for this species are:
•
How much of the Basin is vulnerable to
invasion from Tilapia (based on
temperature tolerance)?
•
Will the critical temperature requirements of
Tilapia change with time (i.e. will they slowly
acclimate to colder water temperatures)?
•
What are the dietary interactions with
Australian native fish species?
•
What are the impacts of Tilapia on
macrophytes in Australia?
•
How do we control vectors for dispersal of
this species (still being used illegally for bait,
released in farm dams etc)?
•
What are the feasible control options for
this species?
Oriental weatherloach
The biology, ecology and environmental impacts
of this rapidly spreading, environmentally
tolerant and highly abundant species in
Australia have been poorly studied and require
urgent investigation. Its potential distribution
is unlimited in the Basin, and it is still being
used illegally for bait. Important ecological and
biological knowledge gaps, which may assist in
control of the species are:
•
Which species of weatherloach occur
in Australia?
•
Improved understanding of ability to survive
desiccation. How long can the species live
out of water and associated implications for
control options (ie. how do you control an
animal that is buried 1m below the base of a
dry dam or creek bed)?
•
Are there control options when the species is
aestivating and thus would we benefit from
examining depths of fish in aestivation?
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29
•
Tolerances of, and reactions to piscicides and
other potential chemical-based control agents.
•
Upstream movement and recolonisation potential.
•
Ability to survival and persist at higher elevations
in Australia.
•
Salinity tolerance of life-history stages.
•
Detailed diet studies in Australian environments.
•
Their importance in the food chain of native
fish communities, including potential lifestages targeted by piscivorous fish; knowledge
of predator-prey interactions and how habitat
complexity may mediate this interaction.
•
Potential differential impacts in billabongs and
streams. (This would assist in prioritisation of
control works). Is impact density dependant?
•
Understanding and control of vectors
responsible for dispersal.
•
Feasible control options in lotic and
lentic environments.
Conclusions
The specific impacts of some of the three
alien species considered here are still largely
unquantified, due mostly to a lack of specific
research. There is very little knowledge of
interactions between impacts and habitats (i.e.
different impacts in lotic vs lentic environments),
climate (wet/dry years), or river regulation (higher
resilience of ‘natural’ environments). There is a
relatively limited range of control options currently
available, and further efforts need to be made
to facilitate the development, refinement, or
application of such methods. Effective management
of dispersal vectors, including social issues,
education and uniform legislative controls, is a
major issue worldwide, and until we understand the
underlying social reasons for the introduction and
dispersal of alien fish, management efforts may be
poorly targeted.
Finally, the question is whether there is a need
to definitively know the specific impacts of each
alien fish species, or whether you simply apply
the precautionary principle (based on reasonable
suspicion of impacts) and commence management
actions to control or mitigate the threat.
30
References
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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
is in conflict with human interests. Pest fish can
be non-native or native (for example, translocated
native species).The pest status of a fish is likely
to change with the interests of the assessor. An
aquatic biologist may regard trout as a serious
pest while to a recreational fisher they are a
valued resource.
What makes a fish a pest? It depends
very much on who is making the decision. For
example, studies have shown that trout are
voracious predators of some native fish and are
seen as a key threatening process (Cadwallader
1996). Yet many state fishery agencies still stock
rivers and lakes with trout and protect them
during their breeding season. They are therefore
a highly valued resource. Pest fish may variously
be destructive, a nuisance, out of place or simply
not wanted. The more accurate answer to the
question “What is a pest fish?” is “A fish that
is in conflict with human interests – because it
causes significant damage to a valued resource”
(Braysher 1993; Olsen 1998).
Management of pest fish should focus on the
desired outcome from management, not just on
killing pest fish. The outcome may be reduced
turbidity, recovery of native fish populations
and/or improved recreational fishing. Highest
management priority should be given to
preventing the establishment of additional
species and limiting the spread of those that are
not fully established. For established species,
management should be based on an integrated
and strategic approach that addresses the range
of factors that threaten the health of native fish
populations and health of the Murray-Darling
Basin generally. Ideally this should be part of an
integrated river restoration program.
Management techniques for pest fish include
physical removal, chemical control,
exclusion devices, habitat manipulation,
rehabilitation of river systems and genetic
manipulation techniques.
Because eradication of established pest fish is
rarely possible (ie. the permanent removal of
every individual), management needs to balance
the costs and benefits of interventions. Besides
local eradication, management options include
strategic management (one-off control, sustained
management, targeted management) or no
management. All too often management is ad
hoc with little strategic planning and little or no
monitoring and evaluation.
The pest status of a fish can change with time,
between areas or according to the perception of
the assessor. Under this definition, native fish
and other aquatic organisms that have been
translocated outside their natural range can
become pests.
There are several aquatic species in the MurrayDarling Basin that are of concern. Until recently,
the attitude towards pests was to try and kill
as many as possible. Each year hundreds of
thousands of carp are trapped, poisoned or
caught by fishermen. The hope had been that if
there was sufficient concerted effort to remove as
many carp and other pest fish as possible, they
could be all but eliminated or even eradicated.
However, we now know that it is unlikely and
unrealistic that established pest fish can be
eradicated, that is, the permanent removal of
every last individual. The possible exception is in
some local situations where the populations are
isolated and relatively low (Koehn and McKenzie
2004; Lintermans 2004). Several conditions
need to be met for eradication to be possible
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(Bomford and O’Brien 1995). It is sobering to note
that no established widespread pest has ever
been eradicated from Australia.The success of
pest fish in Australia is due to aspects of their
biology, habitat changes that provide them with
good conditions, and few diseases and predators
(Olsen 1998, Koehn and McKenzie 2004;
Lintermans 2004). Like most pest animals, pest
fish can rapidly recover their numbers following
knockdown due to adverse climatic conditions
or control operations (Olsen 1998). Most do well
in human disturbed systems. For example, the
Murray-Darling Basin (MDB), produces about
40% of Australia’s primary production. As might
be expected for such an important production
area, there have been extensive changes to the
environment, many of which favour pest fish but
not native aquatic organisms (see Table 2).
Controlling the damage due to pest animals
including fish to an acceptable level is much more
complicated than simply reducing pest numbers.
Before starting, it is important to have a clear
understanding of the problem that pest fish are
believed to cause. The problem should be defined
in terms of desired outcomes. The problem
may be disturbance of the breeding habitat of
native fish, fouling of waterways due to periodic
die-off of carp, poor water quality or complaints
from recreational fishers of an over-abundance
carp. Killing pest fish might be the best way,
but excluding carp from important native fish
breeding sites or re-snagging sections of river to
provide cover and breeding habitat for native fish
may be better and more cost effective in the long
run, especially given the capacity of pest fish to
rapidly recover their numbers (MDBC 2002; 2003).
In other cases, the problem may be based on a
misconception and the best strategy may be a
targeted education program.
Table 2. Some of the changes humans have caused
to the MDB (McLennan 1996)
80% of Murray-Darling water is regulated.
High nutrient load causing toxic algal blooms.
Salinity - 18 fold increase between Yarrawonga (Vic)
and Morgan (SA).
Construction of dams and weirs.
Removal of river bank trees.
De-snagging of river bed.
Use of chemicals for agriculture.
Recreational and commercial fishing.
Introduced fish.
34
The next step is to determine who has the
problem and who is responsible for addressing
it and then to develop and implement strategies
to achieve that outcome or a combination of
outcomes.
Management Approach
Many groups and individuals have an interest
in pest management. They include farmers,
nature reserve managers, financial institutions,
government agencies, animal welfare and
nature conservation groups (Figure 1). Failure
to adequately consult and take into account the
views of the major players when planning and
conducting pest management, can undermine
the chance of success (Olsen 1998). Relevant
stakeholders need to be identified early
and be actively involved in the planning and
implementation of the program. Without an
inclusive, cooperative approach, there is unlikely
to be ownership of the problem and the solution
and hence effective management of the damage
due to pest animals is unlikely.
In addition there are several factors besides pest
fish that need to be addressed in an integrated
approach to achieve the desired management
outcome, e.g. river rehabilitation (Figure 2).
Koehn and Mackenzie (2004) provide an excellent
review of the issues and approach required for
effective management of pest fish in Australian
freshwater systems. Several strategic planning
documents that provide the basis for a systematic
and strategic approach to managing pest fish,
including the Queensland Pest Animal Strategy
(Qld DPI 2002), the Action Plan for Alien Species
in the MDB (MDA 2003), the Native Fish Strategy
for the MDB 2003-2013 (MDBC 2004), and guides
for setting priorities and developing local
management plans (Braysher and Barrett 2000;
Braysher and Saunders 2003).
Management techniques
There are a range of techniques and strategies that
can be used to control the damage due to introduced
fish (Table 3). Further research might increase the
efficiency of the techniques, but current methods
are unlikely to be replaced by high-tech, “magic
bullets”, at least not in the short term. Effective
control of the damage due to pest fish is possible
provided the available techniques are applied
strategically, usually in combination and taking into
account the range of other factors that influence the
biotic and abiotic health of the river system.
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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
Landholders
Government land, water, fisheries
environment protection and nature
conservation agencies
Recreators
Catchment managers
Local government
Effective pest fish management
Recreational anglers
Commercial fishers
Conservation groups
Researchers
Individuals
Rivercare landcare groups
Figure 2. Some of the actions required to rehabilitate a river system
Nutrient management
Pest fish control
Cap on diversions
Improving water quality
Riparian zone management
Restoration of fish passage
River rehabilitation
Improving biodiversity
Environmental flows
Restoration of instream habitat
Management of native fish
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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:
• Electrofishing
• Nets
• Traps in fishways or streams
• Intensive line fishing
In some cases commercial harvesters can be used to
reduce costs. Commercial harvest usually only targets
fish of marketable size and condition. On its own, capture
and removal, whether commercial or not, is unlikely to
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. However, 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
fish including predatory species, including:
• Restoring riparian vegetation.
• Re-snagging sections of river.
• Reducing the impact of cold-water pollution.
The primary aim is to restore habitat so that it is more
suitable for native species, especially predatory fish and to
reduce the suitability of the habitat for non-native species.
Bio-manipulation. (eg. to increase the population of native
predatory species such as golden perch and Murray cod).
The potential impacts from stocking native predators
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:
• Parasites
• Viruses
• Bacteria
Potential non-target impacts from such agents need to be
assessed. No suitable disease agent is currently available.
Fish exclusion devices, including:
• Fish screens on outlets from impoundments
• Electrical barriers
• Bubble curtains
• Sonic devices
Screens have had success in some areas but require
continual maintenance to prevent blockage by debris and
can be breeched by high water flows. The effectiveness of
other devices has not been assessed for large-scale use.
Molecular and similar biological techniques, including:
Techniques are in the early stages of development and
their effectiveness difficult to gauge. Most effort is on the
daughterless carp technique. If shown to be effective, it is
unlikely to be available for field use for many more years.
• Daughterless carp technology
• Lethal genes
• Sterile offspring
36
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Preventing the establishment of new species
Several additional species of non-native fish and
other aquatic animals could establish in the MDB
(Bomford and Glover 2004; see Bomford page 60
this publication). It is important to develop and test
a system that incorporates an appropriate risk
assessment process supported by enforceable
regulation to prevent new introductions in
Australia (Bomford 2003). However, there are
already many species in captivity in Australia
which could establish (QLD DPI 2000). There are
others that are established in some waterways
but which could spread to others such as the
MDB. Of notable concern is Tilapia. This species
has been recorded in the upper reaches of the
MDB in Toowoomba (MDBC 2001), but apparently
failed to establish. An Alert and Rapid Response
Strategy is required that can detect and rapidly
respond to eradicate new incursions.
Setting priorities to manage
established species
Management of established pest fish should
focus on reducing the damage that they cause
to an acceptable level. Plans should be based
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
social outcomes for the area. The plans need to
be locally developed and owned and implemented
by those that have the greatest stake in the
results and whose time and resources will mostly
be required. A whole-of-system approach is
required. Managers need to determine where to
best put their limited resources to get the best
return. Guides have been developed to assist local
groups to determine priority areas for action and
to develop and implement a locally owned plan
to manage the damage due to introduced fish
and other pest animals (Braysher and Barrett
2000; Braysher and Saunders 2003). The guides
promote integration of national, state, regional
and local action plans to control pest animals
including introduced fish so that actions in one
catchment are not compromised by actions in
another (Koehn and Mackenzie 2004). At the
local level, it is suggested that the area to be
treated be broken into separate management
units in recognition that each unit often requires
a specific management approach, and usually a
different set of techniques (Figure 3). A ranking
system based on the threat of introduced fish to
biodiversity and production can help managers
decide where best to focus their resources.
Figure 3. Hypothetical Section of the Murrumbidgee River broken into management units
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37
Measuring success monitoring and evaluation
It is very difficult to determine how effective the
proposed management will be, not the least due
to introduced fish being only one of several factors
that influence the health of the MDB. Almost
invariably, an integrated approach is required
that addresses the range of threats. Predicting
the outcome from implementing amelioration
strategies is also complicated because there
are few studies that have clearly demonstrated
the nature and quantified the extent of the
damage due to introduced fish. Without a good
understanding of the nature and the level of
damage, it is difficult to determine the success or
otherwise of management. Ideally experimental
studies are required to obtain this information,
but as a minimum, management programs
should include an appropriate monitoring and
evaluation strategy that enables the effectiveness
of the management to be assessed.
Monitoring and evaluation helps to:
•
determine whether the objectives and the
management strategy were appropriate;
•
improve the focus and procedures of a project
as it proceeds;
•
develop the skills and understanding of people
involved in a project;
•
provide information for planning a new
project; and
•
justify and promote a project to the
wider community.
Monitoring and evaluation programs should
be specifically tailored to each pest fish
management program. Some examples of what
might be monitored are:
Indicators of inputs – these record the resources
that the project is using and can indicate how
resources may be used more efficiently. These
inputs include:
•
project finances; and
•
time, materials, equipment and funding
contributed by the community.
Indicators of outputs – these record progress and
the level of activity, including:
38
•
whether the project is being implemented
on schedule;
•
the observations, feelings and concerns of
the people involved in the project (employees,
volunteers, project managers) about how will it
is working; and
•
publications, field days, workshops, weight of
carp removed.
Indicators of outcomes – indicate whether the
project is being successful. For example:
•
increases in native fish species and density of
water plants after pest fish control;
•
changes in community attitudes; and
•
improvement in water quality.
Involving the local community in the monitoring
program helps to maintain local ownership and
enthusiasm for the management program as well
as gathering essential information for those that
need to assess the success of the program. The
following can help to involve the local community
in monitoring:
•
Be very clear about what needs to be
monitored and why.
•
Keep it as simple as possible and compatible
with other routine management practices.
•
Make the process quick and easy.
•
Provide regular feedback to the community on
results in an appropriate format.
•
Display or disseminate the results in a
public place.
Appropriate and regular reporting, especially if
it includes feedback on successes, interesting
information on local members of the group or
interesting information on pest fish management
from elsewhere can help keep group members
involved and informed on progress with
the program.
References
Bomford, M. 2003. Risk Assessment for the Import and
Keeping of Exotic Vertebrates in Australia. Bureau of
Rural Sciences, Canberra.
Bomford, M. and Glover. J. 2004. Risk assessment
model for the import and keeping of exotic freshwater
and estuarine finfish. A report produced by the
Bureau of Rural Sciences for The Department of
Environment and Heritage.
Bomford, M. and O’Brien, P. 1995. Eradication or
control for vertebrate pests? Wildlife Society Bulletin
23: 249-255.
Braysher, M. 1993. Managing Vertebrate pests:
Principles and Strategies. Bureau of Resources
Sciences, Canberra.
Braysher, M. and Barrett, J. 2000. Ranking areas for
action. A guide for carp management groups. MurrayDarling Basin Commission, Canberra.
E m e r g i n g I ss u e s i n A l i e n F i s h Ma n ag e m e n t i n t h e M u r r ay Da r l i n g B a s i n – W o r k s h op , 3 0 - 3 1 May 2 0 0 6
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 the Murray-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.
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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]
Abstract
The Murray-Darling Basin (MDB) jurisdictions
have a range of legislation, policies and
programs aimed at dealing with the threats
posed by alien and exotic species, as
well as translocated native species. This
paper summarises the existing alien fish
management (control) mechanisms in MDB
jurisdictions. This summary suggests that
the major area of deficiency in alien species
management across jurisdictions is in the policy
response of jurisdictions to new infestations
and control of existing populations.
The paper proposes a series of initiatives and
policies that could be employed to improve on
these deficiencies, including:
40
•
Improvement in regulation of aspects of the
hobby/aquarium industry especially with
regard to licensing non-permitted species
already present in Australia; and
•
Adoption of the black and grey list as proposed
in the Strategic Approach To The Management
Of Ornamental Fish In Australia – Consultation
Draft (2005).
Alien species pose a significant challenge to all
levels, including managers, scientists and the
community. One of the major challenges facing
natural resource managers in all jurisdictions is
the management of the ‘desirable’ alien species
(eg. Redfin perch and trout) to prevent adverse
impacts, both direct and indirect, on native
fish species.
•
Improved investment in education
and awareness;
•
Adoption of uniform classification and
regulations for alien species;
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.
•
Improved regulation and enforcement of
human assisted dispersal ie use of fish as
live bait;
Introduction
•
The need for ongoing, intensive and rigorous
monitoring and control of populations as
soon as they are detected;
•
An urgent need for a national policy and
approval for the use of rotenone to undertake
spot eradication of new infestations;
•
Further development of other techniques
and transfer of knowledge for immediate use
prior to approval of rotenone or in preference
to rotenone; and
•
Further the immediate development of an
alien species response framework for the
Murray-Darling Basin;
The Murray-Darling Basin (MDB) is
Australia’s largest river system that stretches
across five States and Territories in Eastern
Australia, including South Australia, Victoria,
New South Wales, Queensland and the Australian
Capital Territory.
These jurisdictions have a range of legislation,
policies and programs aimed at dealing with
the threats posed by alien and exotic species,
as well as translocated native species. The
Commonwealth government also has a role in
the management of exotic and alien species
through various legislation and import controls.
Each State and the Commonwealth have separate
legislation related to management of alien and
exotic species (hereafter referred to as aliens).
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Despite the borders of each state, they are
all connected by the Murray-Daring river system,
resulting in the potential of any alien species,
once established in a jurisdiction, being able to
disperse from one state to another. Due to this
connectivity between states, any alien species
that becomes established could potentially
inhabit the entire system and further spread from
there or vice versa; spread from neighbouring
catchments into the Murray-Darling.
This paper summarises the existing alien fish
management (control) mechanisms in MDB
jurisdictions. The aim is to highlight differences
between jurisdictions and determine what actions
can be undertaken to minimise the risk posed by
alien species. Commonwealth legislation largely
relates to import of potentially invasive species
rather than the response to and legislation
for preventing further spread once introduced
into the country and hence is not discussed in
this paper. For further information about the
Commonwealth legislation and management
of ornamental fish in relevant jurisdictions see
A Strategic Approach To The Management Of
Ornamental Fish In Australia – Consultation Draft
(2005) which can be downloaded from Bureau of
Rural Sciences website at:
www.affashop.gov.au/PdfFiles/ornament_fish6.pdf
The author has exercised due care and skill in the
preparation and compilation of the information
and data set out in this paper. Notwithstanding,
the authors and contributors disclaim all liability,
including liability for negligence, for any loss,
damage, injury, expense or cost incurred by any
person as a result of accessing, using or relying
upon any of the information or data set out in this
publication to the maximum extent permitted by
law and this paper should not be used as
legal advice.
Sincere thanks to the following people that
provided information contained within this
paper from around the Basin:
•
Peter Jackson and Natalie Baker (QLD);
•
Mark Lintermans (ACT);
•
Fern Hames (VIC), Brad Tucker and
Lousie Galli (DPI); and
•
David Harasti and Sharon Molloy (NSW).
Legislation related to
the possession or release
of alien species and
enforcement capacity
South Australia
In South Australia, the relevant legislation
regarding management of fisheries
resources is presently the Fisheries Act 1982
(soon to be replaced by the Fisheries Management
Act 2007) and the associated regulations. It is an
offence under Section 50 of the Fisheries Act 1982
to release or permit exotic fish to be released
without the granting of a permit authorising that
activity from the Director of Fisheries.
It is also an offence under Section 49 of the
Fisheries Act 1982 to import or sell, purchase,
deliver possess or control exotic species without
the granting of a permit authorising that activity
from the Director of Fisheries. The Fisheries (Exotic
Fish, Fish Farming and Fish Diseases) Regulations
2000 contains a list of species for which permits
will be granted by the Director of Fisheries
(Schedule 4) as well as a list of exotic fish to which
section 49 does not apply (Schedule 3).
The sections of the Fisheries Act that refer to
possession or release of alien species also
relates to all fish of that class whether they
be aquaculture or aquarium fish and acts as a
control for fish stocking. Fish stocking requires
approval from the Director of Fisheries under
Section 50 (2) of the Fisheries Act 1982.
Fish species that are exotic for the purposes of
Sections 49 and 50 are defined in Section 5 (1) of
the Fisheries Act 1982. This states that unless the
contrary intention appears:
“fish” means an aquatic organism of any
species and includes the eggs, spat or spawn, or
the body, or part of the body (including the shell)
of such an organism;
“exotic fish” means fish of a class declared by
regulation to be exotic fish.
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).
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41
The declaration of exotic fish in the Fisheries
(Exotic Fish, Fish Farming and Fish Diseases)
Regulations 2000, states that, live fish of species
(other than those species listed in Part 1 of
Schedule 2) which 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.
Part 1 of Schedule 2 is essentially a list
of the ‘native fish’ of Australia, both marine and
freshwater, which would not be declared exotic,
unless they are a farmed fish (defined under the
act). Hence any fish not listed in
this list and belonging to a kingdom or
phylum specified in Part 2 of Schedule 2
are declared exotic.
Section 51 of the Fisheries Act 1982, provides
the power to make regulations for the control of
exotic fish and the control of disease in fish. This
includes requirements that the:
•
•
Director of Fisheries be notified of the
occurrence of disease or symptoms of disease
in aquacultured fish;
Bringing into the State or possession or
control of fish that may be affected by disease
is prohibited.
This Section (51) also outlines that the powers of
fisheries officers for the detection, prevention,
elimination or control of disease in fish,
eradication or containment of exotic fish and
regulation of the disposal of the water in which
fish have been kept are made by regulation and
are contained in Fisheries (Exotic Fish, Fish Farming
and Fish Diseases) Regulations 2000.
Compliance officers of the Department of
Primary Industries and Resources, South
Australia (PIRSA) undertake enforcement of the
regulations in South Australia. In conjunction with
compliance officers, FishCare volunteers also
operate in an educational role with recreational
fishers, educating them about the various
regulations and rules regarding recreational
fishing and alien fish.
Victoria
The Fisheries Act 1995 provides legislation
for the management of noxious aquatic species.
Part 5, Division 2 of the Act provides for the
Governor in Council, by Order in Council, to
declare any aquatic species to be noxious, other
than protected aquatic biota, protected wildlife or
protected flora.
42
Unless authorised under the Fisheries Act, a
person must not bring into Victoria, or take,
hatch, keep, possess, sell, transport, put into any
container or release into Victorian waterways any
aquatic species that is declared to be noxious.
Compliance of the above legislation is managed
and enforced by Fisheries Victoria, a division
of the Department of Primary Industries (DPI).
Noxious aquatic species inspections currently
form part of station operations but are mostly
focussed on the ornamental sector and are
opportunistic. Occasionally targeted operations
are planned. The Act also provides for:
•
offences concerning prohibited noxious aquatic
species;
•
noxious aquatic species permits, and permit
revocation;
•
authorisation to transport, contain or release
noxious aquatic species;
•
notice to be given of the location of noxious
aquatic species;
•
seizure and removal of noxious aquatic
species;
•
prevention of the spread of noxious aquatic
species; and
•
no penalty if the noxious aquatic species
specimen is killed immediately.
Victoria will be updating its noxious
aquatic species list in line with the recent
endorsement of a national noxious fish list in the
Strategic Approach to the Management
of Ornamental Fish.
The Flora and Fauna Guarantee Act 1988 enables
the listing of Action Statements which define
potentially threatening processes. One such
process has been defined as the “Deliberate
or accidental introduction of live fish into
public or private waters within a Victorian river
catchment in which the taxon to which the fish
belongs cannot reliably be inferred to have been
present prior to the year 1770 AD” (SAC 1992).
Action Statement No. 190 ‘Introduction of live
fish into waters within Victorian river catchments’
follows the listing of that potentially threatening
process and describes the actions to be taken to
ameliorate the adverse effects of this process.
The Guidelines for Assessing Translocations of
Live Aquatic Organisms in Victoria Department
of Primary Industries (2003), outline the risk
assessment process for planned translocations.
A Translocation Evaluation Panel (TEP,
comprising representatives from the Fisheries
Co-Management Council, DPI and DSE) assesses
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Initial Screening Applications against developed
protocols. Proponents may be required to submit
full Risk Assessments (proforma is available). The
TEP advises the Secretary, DPI, of their decision
and the Secretary may approve or refuse the
application.
The “Victorian Pest Management Framework”
provides a planning framework to give strategic
direction to species strategies and Action Plans.
The Framework is intended to cover aquatic fauna
as well as terrestrial species. It is anticipated that
new strategies for aquatic fauna will be developed
from the Framework.
New South Wales
The management of noxious fish in NSW is
through the Fisheries Management Act 1994.
Enforcement is conducted by compliance officers
operating on the authority of the Fisheries
Management Act 1994, with penalties of up to
$11,000 for possession or sale of noxious fish.
There are three classes of noxious fish under the
Fisheries Management Act 1994 representing the
different levels of threat they pose to the aquatic
environment. Classifications range from Class
1 (possession and sale banned and have the
capacity to order destruction), through to Class 3
(discouragement of possession).
Different rules apply for each class in regard to
the possession or sale of these species. Noxious
listing provides NSW Department of Primary
Industries (Fisheries) with the power to seize
and destroy the noxious species, or require their
destruction, under certain circumstances or for
certain classes of species.
Listed noxious fish include three Tilapia species
(Class 1), plague minnow (Class 1 outside the
greater Sydney region) and Carp (Class 3). The
‘Strategic Approach to the Management of
Ornamental Fish’ (Bureau Of Resource Sciences,
2005). recommends an expanded list of noxious
fish, which will be adopted by NSW once this has
been endorsed.
Under recent changes to the Fisheries
Management Act 1994 and Regulations, it is now
illegal to import any live noxious fish (or certain
other aquarium, aquaculture and pest species)
into NSW without a permit.
Most species of aquarium fish can be legally
imported into NSW from other States without a
specific permit, however, certain live fish cannot
be brought into NSW without a specific permit
from the Minister for Fisheries. These fish pose a
threat to the aquatic environment and/or have the
potential to introduce diseases. A list of species
that cannot be imported without a specific
permit are contained on the NSW DPI website
(www.dpi.nsw.gov.au).
The introduction of fish to fresh waters outside
their natural range is listed as a Key Threatening
Process (KTP) under the Fisheries Management
Act 1994 and requires the development of a
threat abatement plan. Predation by gambusia
is also listed as a KTP under the Threatened
Species Conservation Act 1995 because of its
impacts on threatened frogs, and is covered by
an approved threat abatement plan.
A Hatchery Quality Assurance Program has
been developed in NSW to limit the chances
of translocation of non-target species through
aquaculture stocking.
Australian Capital Territory
The Fisheries Act 2000 prohibits the release
of live fish into public waters without written
approval of the Conservator of Wildlife. The
Nature Conservation Act 1980 also prohibits the
release of live fish into waters in the Territory.
The ACT has declared the original list proposed
by the ‘Strategic Approach to the Management
of Ornamental Fish: consultation draft’ as ‘pest
animals’ under the Pest Plants and Animals Act
2005. This Act also allows the declaration of
pest animals as either ‘notifiable pest animals’
(where the presence of a pest animal must be
notified to the chief executive) or ‘prohibited pest
animals’ (where the supply or keeping of the
animal is prohibited).
The majority of the pest fish currently listed
under the Pest Plants and Animals Act 2005 are
listed as prohibited pest animals. Of the three
species which form the focus of this workshop,
Oriental weatherloach is not listed as either a
prohibited pest animal or notifiable pest animal
(as they are still kept by aquarium hobbyists),
Tilapia is listed as a prohibited pest animal,
and Redfin perch is not listed as a pest animal
in the ACT.
The Pest Plants and Animals Act 2005 contains
provisions for the preparation of a pest animal
management plan for a pest species, but a plan
is not mandatory. A pest animal management
plan may outline requirements for the following,
having regard to the potential threat and the
practicality of control measures:
•
managing the environmental and agricultural
impact of a pest animal in a cost effective way
if its eradication is impractical;
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43
•
controlling potential sources of invasion
through trade, transport and escape from
urban areas.
The Fisheries Act 2000 also has provision for the
declaration of noxious fish, but to date, none have
been declared.
It is an offence to commercially supply a
prohibited pest animal, and is also an offence to
recklessly supply a prohibited pest animal (e.g
as a contaminant of something else). It is also
an offence to keep a prohibited pest animal, or to
recklessly dispose of one
Section 79 of the Fisheries Act 2000 prohibits,
without reasonable excuse, release of a live fish
into public waters (unless the fish was taken from
the part of the public waters into which it
is released).
Section 49 of the Nature Conservation Act 1980
prohibits the release of an animal that is not
a native animal from captivity if the release
threatens the survival, abundance or evolution of
any species of native animals.
Enforcement capacity under both legislation is
largely the responsibility of park rangers.
44
Queensland
The Fisheries Act 1994 and the Fisheries
(Freshwater) Management Plan 1999 controls the
management of noxious fish.
Possessing, rearing, selling or buying noxious
fishes is unlawful without a permit. A person
who takes or possesses noxious fish is required
to immediately destroy the fish and notify an
inspector of the destruction within two business
days of taking or first possessing them; or
immediately give the fisheries resources to an
inspector; or immediately notify an inspector of
taking or possessing noxious fish.
Similar provisions also exist for non-indigenous
fish (i.e. alien species that are not classified as
noxious) unless they are listed under Schedule 6
of the Fisheries Regulation 1995.
The Department of Primary Industries and
Fisheries has Boating Patrol officers based at
Wondai and Roma to enforce inland fisheries
regulations. Boating Patrol officers based in
coastal centres also undertake a percentage of
their duties in freshwater.
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.
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45
Nature Conservation Nature Conservation No formal
Act 1980;
Act 1980;
program, but
Fisheries Act 2000; Fisheries Act 2000; ad hoc activities
conducted. Info
Pest Plants &
Pest Plants &
on website: http://
Animals Act 2005
Animals Act 2005
www.environment.
act.gov.au
Fisheries Act 1994
Fisheries Act 2000;
Fisheries Act 1994
Australian Capital
Territory
Fisheries Act 1994
NSW Fisheries
Management Act
1994
Fisheries Act 1995
The Invasive
Animals CRC is
addressing this for
all states
The Invasive
Animals CRC is
addressing this for
all states
In place. Info on
web http://www.
dpi.qld.gov.au
Monitoring ‘hot
spots’
No formal
program, but
regular monitoring
programs likely to
detect
Yes, depending on
location
In place
Some in place
No formal program On a case by case
eg. ‘Fishnotes’, &
basis. Rare
website - http://
www.fisheries.nsw.
gov.au/
Some in place
eg. website- http://
www.dpi.vic.gov.
au/DPI/
Rapid response
Minimal activity
presently, but
may change with
new pest animal
management plans
Unknown
Unknown
Unknown
Rapid response
being trialled
and methodology
revised. Pest
Fish Operational
Strategy being
updated
New pest animal
management plans
to be developed
under the Pest
Plants & Animals
Act 2005
Fisheries
Management Act
2007 will replace
present Act
Spot eradication or Control activities
Other
containment of new for new populations
infestations
NB: The Invasive Animals CRC is presently addressing the development of control actions for new populations. Additionally, a permit is presently being sought regarding use of Rotenone as a
limited response to new infestations similar to the Queensland model. In Victoria, new Regulations are expected to be in effect in 2008.
Queensland
NSW Fisheries
Management Act
1994
NSW Fisheries
Management Act
1994
New South Wales
Pest Plants &
Animals Act 2005
Fisheries Act 1995
Fisheries Act 1995
Detection
programs for new
infestations
Some in place
No formal program Unknown
eg. website- http://
www.pir.sa.gov.au
Victoria
Fisheries Act 1982
Fisheries Act 1982
Fisheries Act 1982
South Australia
Enforcement
Education
/ extension
activities related
to alien species
management
Release
Legislation
Possession
State
Table 1: Summary of alien fish management (control) mechanisms in Murray-Darling Basin jurisdictions
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
Australia
Victoria
New South
Wales
Australian
Capital Territory
Queensland
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
46
Term
State
Definition
Exotic fish
South Australia
Live fish of species (other than species listed in Part 1 of Schedule 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 Fisheries Regulations
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 the Fisheries 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
species
Victoria
A noxious aquatic species declared under Section 75. The Governor in Council
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
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Education / extension
activities related to alien
species management
South Australia
Information regarding the legislation that applies
to existing populations of alien species is
provided via
•
Distribution of printed material;
•
A sign posting program;
•
The FishCare Volunteer Program; and
•
The PIRSA web site (www.pir.sa.gov.au).
At various field days, fishing competitions and
other relevant events across the state, the MDBC
NFS Coordinator and FishCare volunteers
distribute PIRSA and MDBC NFS printed
material. Awareness of alien (new, potential and
existing) species and the impact of them is the
main aim of these activities, while also providing
insights into alien fish behaviour obtained from
SA and interstate research.
Victoria
Education activities in Victoria include the
development of communication material related
to recently declared noxious aquatic species
and measures to mitigate the risk of species
spreading (eg. Victorian DSE’s “Keep your boat
clean” campaign).
Victoria plans to publicise its revised noxious
aquatic species list in conjunction with the
promotion of the new DAFF Strategy. In
addition, Victoria has established an Ornamental
Consultative Committee. This Committee
provides advice in regards to communication
and enforcement planning, as well as proposing
aquatic species for listing as noxious.
For topical issues, Fisheries Notes are prepared
by DPI and disseminated to the relevant
stakeholders and placed on the DPI Website.
At a range of field days and other events across
the State, MDBC publications on noxious and
alien species including Carp are distributed
and discussed, and a model of a Williams Carp
Separation Cage demonstrated.
New South Wales
There is extensive information on the Fisheries
section of the DPI website. Other activities
undertaken include:
•
Attendance and presentations at open days,
seminars, working groups;
•
Dissemination of pamphlets/brochures, such
as “Don’t Dump That Fish”, “Aquatic Pests in
NSW”, pest identification cards (marine only),
and species specific brochures; and
•
Media releases.
NSW plans to publicise its revised noxious aquatic
species list in conjunction with the promotion of
the new national ornamental fish strategy. NSW
is preparing a poster on Redfin perch (targeting
recreational fishers), which will be distributed to
bait and tackle shops and other relevant outlets.
Australian Capital Territory
The ACT has previously distributed the “Stop
before you release that aquarium fish” brochure,
and will distribute any communication products
arising from the National Ornamental Fish Policy
Working Group.
Promotion is undertaken to fishing clubs on the
ban on using live bait. The dangers of discarding
live bait and the potential for the establishment of
feral populations (e.g. Oriental weatherloach) are
also highlighted.
The importance of some dams as barriers to
fish invasions (they prevent spread of Brown
trout, Carp and Redfin perch into some subcatchments) is highlighted to the local water
authority, so that these considerations can be
incorporated into their forward planning. The
potential for inter-basin transfers to spread
aliens has been similarly highlighted, and
embraced. Any such proposals would now be
conditional on the use of screens and other
preventative equipment.
Queensland
Since 2000, Queensland has operated under the
“Control of Exotic Pest Fishes, An Operational
Strategy for Queensland Freshwaters 20002005”. The primary focus is on education given
that human-assisted dispersal is a major cause
of new introductions (see Lintermans 2004).
Recent new infestations have caused a rethink
of the effectiveness of the education program.
As a result, a new-targeted campaign has been
launched in North Queensland. This will be
followed up in South East Queensland later in the
program. This education program also focuses on
correct identification of pest fish with brochures
and wallet sized identification cards.
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47
Additionally, the Freshwater Fisheries Unit has
provided the Boating Patrol with identification
manuals for noxious fish and with a policy
procedure document together with relevant
books (e.g. Axelrod et al. 1975).
Regulation and use
of Live Bait
yabbies as bait (dead or alive) is prohibited
outside their natural environment or range.
This is to prevent species from becoming
established in foreign habitats and causing
environmental damage.
Currently three species can be used as live
bait, they are:
•
Redclaw crayfish (Cherax quadricarinatus)
- native to the Gulf of Carpentaria Drainage
Division and some river basins in the far
northern portion of the East Coast Drainage
Division. Redclaw can be used as bait only
in these areas
•
Shrimp (Macrobrachium australiensis) found throughout Queensland and can be
used as bait in all areas of the state
•
Yabby (Blueclaw crayfish) (Cherax
destructor) - found naturally in the MurrayDarling, Lake Eyre and Bulloo-Bancannia
Drainage Divisions, and some river basins
in the East Coast Drainage Division. Yabbies
can be used as bait only in these areas.
South Australia
The use of live bait is not directly legislated
against in South Australia (provided the species
does not have a minimum legal size), however
under Section 50 of the Fisheries Act 1982, alien
fish cannot be released into the natural waters
and hence cannot be used as live bait.
Victoria
The Fisheries Act 1995 prohibits the use of live
noxious fish (as defined in Schedule 75 of the
Act) as bait. It is an offence to use live fish as
bait in Seven Creeks and certain tributaries.
Presently, this issue is addressed indirectly
via the prohibition of holding undersize fish.
Stocking of fish into any water is managed via
Permit and translocation approvals.
New South Wales
The Fisheries Management Act 1994 prohibits the
release of live fish into any waters (ie. the sea, a
river, creek or other naturally flowing stream of
water or a lake) without a specific permit from
the Minister or under an aquaculture permit. It
does not apply to the immediate return of fish to
waters from which they were taken.
The Fisheries Management (General) Regulation
2002 prohibits the use of live fish for bait in
inland waters.
Australian Capital Territory
The Nature Conservation Act 1980 prohibits the
release of live fish into public waters without
written approval of the Conservator of Wildlife.
The Fisheries Act 2000 also prohibits the use of
live finfish as bait and prohibits the possession
of live fin fish for use as bait while beside public
waters.
Queensland
Detection programs for
new infestations
South Australia
Presently South Australia has no formal
detection network for freshwater species
beyond the network of FishCare volunteers.
The public can report sightings via a toll free
1800 number and publications are distributed
that request people notify FishWatch if an
unusual fish is caught. Several incursions have
been identified to date, most notably Caulerpa
in West Lakes/Port River.
The NRM Boards in SA also have ongoing
monitoring programs for terrestrial and
aquatic pests, while extensive bio-surveys,
focussed mostly on terrestrial species, are
also being undertaken throughout the state to
identify present incursions and extent.
Victoria
Extensive and ongoing faunal surveys and
river audits assist in monitoring existing
distributions, and detection of new incursions
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
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New South Wales
Queensland
Extensive and ongoing faunal surveys and river
audits assist in monitoring existing distributions,
and detection of new incursions and range
expansions (eg. discovery of Redfin perch in the
upper Lachlan by NSW DPI researchers).
Queensland has refocussed its activities to give
priority to “vulnerable catchments” and “hot
spots” within those catchments. The concept is
to increase the chances of early detection of
any infestations. Surveillance by both a
community network and by a Fisheries
team provide information.
The public can report pest sightings to the
Aquatic Pest Taskforce through the Protected,
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.
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49
Spot eradication or containment of new infestations
Table 4: Control method for management of pest infestations
Containment
Rotenone
Other
South Australia
Netting, electrofishing,
barriers, exclusion devices
Prior to 2000 – not
currently permitted
Exclusion of activities and
control of entry into affected
areas
Victoria
Netting, electrofishing,
barriers, exclusion devices
Nil permitted
New South Wales
Public Education, Biological Approval to use rotenone
Control, Translocation Policy granted from Australian
Pesticides & Veterinary
Medicine Authority
for eradication
Explosives have been used
in limited cases
Australian Capital Territory
Targeted education
programs, ban on using live
finfish as bait,
Used prior to ~2000, not
currently used
Lime has been used for spot
eradications in small
farm dams
Queensland
Exclusion devices (eg.
screens installed on
water outlets)
Restricted permit to use
rotenone in small isolated
waterbodies less than
2 hectares and no deeper
than 2 metres
Physical removal by
electrofishing or netting
South Australia
Present eradication procedures in South Australia
are focussed around containment and physical
removal due to the inability to use rotenone
following national restrictions. It is expected that
the granting of a national licence will permit use
of rotenone in a small number of circumstances
where it is an enclosed waterbody or very small in
nature and no threatened species exist.
Present controls focus on excluding various
fishing and boating activities such as anchoring
from areas and restricting public entry following
identification of alien plants, while new
infestations of fish are controlled using physical
removal such as electrofishing and netting in
conjunction with regular and ongoing monitoring.
Victoria
Rotenone is not available for use, unless approved
by the Minister.
It is an offence to return noxious fish to the wild
and hence recreational anglers catching noxious
fish cannot return them to waterways.
Persons can apply for Noxious Aquatic Species
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
commercial fishers to remove Carp via netting
and electrofishing for commercial purposes.
New South Wales
Eradications have been attempted on fish
contained in small closed systems (eg. Jack
Dempsey cichlids in disused quarry, One-spot
livebearers in golf course ponds), and new
infestations of Caulerpa.
Eradication of new infestations is hampered by
the lack of specific surveillance and reporting
programs (to detect new pest species at an
early stage) and the lack of agreed and tested
emergency response arrangements for inland
waters (it is understood these are arrangements
are under development as part of a project
by the Invasive Animals CRC). In reality, new
infestations tend to be either in confined
waterbodies, reducing necessity for emergency
response, or already too widespread for
realistic eradication.
NSW has successfully applied to the APVMA, on
behalf of all jurisdictions (excluding Victoria) for
a national permit to use rotenone for pest
fish control.
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Australian Capital Territory
The ability to act quickly to eradicate outbreaks is
hampered by the current inability to use rotenone
(not registered in the ACT). The current national
registration process will improve the capacity of
the ACT to deal quickly with new infestations.
Rotenone has been used successfully in the
past to eliminate small populations or localised
occurrences of alien species such as Carp in farm
dams, Eastern gambusia in ponds, trout from
small sections of stream above a barrier etc (See
Lintermans 2000).
However the inability to respond quickly in the
past to newly detected invasions has resulted
in the establishment of Redfin perch in 1983
(Lintermans et al. 1990), and the establishment of
new population of weatherloach in 1990. In both
cases, the delays were the result of protracted
intra-departmental negotiations about whether
and how to proceed.
Slaked lime has also been used to eradicate Carp
from farm dams in the Canberra region.
Queensland
Fisheries are developing a rapid response
approach, however their ability to act is limited by
available eradication tools.
At present, Fisheries has a restricted permit to
use rotenone in small isolated waterbodies less
than 2 hectares and no deeper than 2 metres.
Eradications have been carried out in small dams
but the permit is often too restrictive for many
situations. Fisheries are working with other
states to get a less restrictive permit.
Fisheries have developed an Operational Manual
for the use of rotenone. Eighteen staff have
been trained and a store of rotenone is available
together with dispersal and safety equipment.
Through a regional planning process, Queensland
have undertaken a number of containment
activities. An example is screens that have been
installed on water off-takes from Boondooma
Dam in south-eastern Queensland and from
Tinaroo Dam in north Queensland. In both cases,
the screens have been installed to prevent
the spread of Tilapia (at considerable expense
to the infrastructure owners). In the case of
Tinaroo dam, the screens are protecting the Gulf
Catchments from possible Tilapia infestations.
Control activities for
established populations
The states are involved in the Invasive Animals
CRC which is developing a series of new
control techniques like ‘Daughterless Carp‘
for application to invasive fish such as Carp
and other species. Each jurisdiction also has a
range of activities that it presently undertakes
to control established populations, from
commercial fishing to recreational fishing
competitions that target alien species to
spot eradications.
South Australia
Alien fish of the River Murray are the only
population presently being targeted with control
activities, specifically a feral based commercial
operation. In addition, it is an offence to return
alien fish to the wild and hence recreational
anglers catching alien fish cannot return them
to the waterways. Additionally Carp fishing
competitions also target local abundances
of Carp and other alien species with several
significant catches in recent years.
Victoria
Rotenone is not available for use, unless
approved by the Minister.
Persons can apply for Noxious Aquatic Species
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
commercial fishers to remove Carp via netting
and electrofishing for commercial purposes.
In addition to these activities, Victoria originated
the idea of Carp (Williams) separation cages and
researchers from the Arthur Rylah Institute are
working to improve this design for adoption at all
fishways being constructed as a part of the Sea
to Hume Dam fishway program.
New South Wales
Few ongoing control activities, apart from
involvement in research such as the ‘Daughterless
Carp’ project. For an eradication of Jack Dempsey
cichlids, progressively larger blasts of explosives
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.
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51
Australian Capital Territory
Through education activities largely targeted at
anglers, spot eradications from farm dams, and
low-level surveillance and monitoring activities,
two catchments (Cotter River upstream of Cotter
Dam; Queanbeyan River upstream of Googong
reservoir) are free of Carp and one catchment
(Cotter River upstream of Cotter Dam) is Redfin
perch free. The importance of the barrier posed
by water supply dams to upstream colonisation by
alien species has also been emphasised in liaison
activities with local water and land management
agencies. Such barriers have prevented the
upstream establishment of Carp, Redfin perch,
and Brown trout in the Cotter River system.
Queensland
Queensland has few ongoing control activities.
The South East Queensland Carpbusters initiative
aimed to improve the riverine environment of
the Logan and Albert River systems through
reducing the numbers of Carp and restocking
with native fingerlings is starting in the Basin.
Forest Lakes near Brisbane is regularly netted
to reduce Tilapia numbers and may serve as an
experimental site for other techniques.
Queensland will use the results of vulnerability
analysis research on Carp and Tilapia to
determine if targeted control measures are
possible elsewhere.
Summary
In summarising the information contained
it is apparent that legislation relating to the
management of alien species exists in each
jurisdiction. However, the major deficiency in
alien species management across jurisdictions,
not withstanding differences in terminology,
is in the policy area. Specifically, responses of
the jurisdictions to new infestations and control
of existing populations with limited scope for
activities that will impact on populations once
established – the lesson here is a need for
ongoing, intensive and rigorous monitoring
and control of populations as soon as they are
detected to minimise impacts and increase the
likelihood of eradication.
As a priority, approval must be sought for use of
rotenone to undertake spot eradication of new
infestations in all jurisdictions, with sensible
restrictions and appropriate training in safe
handling of this chemical. In addition, other
techniques already available such as physical
52
removal or the use of explosives should be
further developed for immediate use prior to
approval for rotenone.
As a part of this, an assessment of the suitability
of rotenone for use in all aquatic environments,
including rivers, should be undertaken to
demonstrate the benefits and limitations of
this technique and spur on the development
and investigation of other novel methods for
eradication. Further the development of an
alien species response framework for the
Murray-Darling Basin that can be adopted by
all jurisdictions is required, thus forming the
cornerstone of a coordinated response strategy.
One other obvious necessity that would be part
of the response strategy is improved investment
in education and awareness for all jurisdictions.
While significant work is undertaken in this
area and information is distributed, infestations
are still occurring throughout the Basin
that could be reduced or prevented through
improved awareness. Queensland has adopted
a ‘catchment at risk’ methodology, to identify
areas for investment of limited resources. This
approach is most likely to minimise the likelihood
of Tilapia accessing waters of the Murray-Darling
Basin and spreading through it in a manner
similar to that of Carp in the 1960’s.
Improvement is required in regulation of aspects
of the hobby/aquarium industry especially
with regard to licensing non-permitted species
already present in Australia and management of
Koi carp and other similar species. Appropriate
arrangements are being proposed in Bureau Of
Rural Sciences (2005) that will partly address this
issue but states will be required to enforce any
new licensing arrangements. The black and grey
list produced by this group should be adopted
by all jurisdictions as the minimum listing of
alien species not permitted unless granted with
exemptions and licences to regulate
these species.
Finally, all jurisdictions should seek to adopt
uniform classification and regulations for alien
species (potentially to align with South Australia’s
new Fisheries Management Act 2007), this will
finally be the case with all jurisdictions now using
the word ‘noxious’ to describe unwanted alien
species – the remaining challenge for managers
in this respect is how the ‘desirable’ alien species
(eg. Redfin perch and trout) are managed.
Another challenge is human-assisted dispersal.
The majority of new infestations or extensions
to range that have occurred in Australia are as a
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result of humans physically transporting them
to new waterbodies. Improving the regulation
and enforcement of human assisted dispersal
(ie. use of fish as live bait across jurisdictions) in
conjunction with improved awareness will assist
with this issue.
Alien species pose a significant challenge to
all levels, including managers, scientists and
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.
SAC 1992 Final recommendation on a nomination
for listing: ‘Deliberate or accidental introduction
of live fish into public or private waters within a
Victorian river catchment in which the taxon to
which the fish belongs cannot reliably be inferred
to have been present prior to the year 1770 AD’
(potentially threatening process) (Nomination No.
204). Scientific Advisory Committee, Flora and
Fauna Guarantee. Department of Conservation and
Natural Resources. Melbourne.
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.
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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
threat across both the Murray-Darling Basin
and Australia. The invasion of carp Cyprinus
carpio illustrates how quickly an introduced
fish species can spread and dominate fish
communities. Carp are the highest profile
aquatic invader and have received the most
attention, hence, provide an ideal case study
from which to learn lessons for alien species
management. The need for risk assessments to
predict future impact of species is highlighted
and the adaptation and application of existing
policy and management documents that have
been produced for carp should readily assist the
management of other species.
Introduction of alien species is considered a
greater threat to the biodiversity of freshwater
ecosystems because of the intentional and
unintentional release of organisms (Sala et al.
2000). Australia has five of the world’s eight most
invasive fish taxa as listed by the International
Union for the Conservation of Nature (Lowe
et al. 2000): Brown trout Salmo trutta, Carp
Cyprinus carpio, Mozambique tilapia Oreochromis
mossambicus, Rainbow trout Oncorhynchus
mykiss, and Gambusia Gambusia affinis/holbrooki.
Four of these species occur in the Murray-Darling
Basin with the fifth (Tilapia) under consideration
at this workshop as the risk of its entry into
the Murray-Darling Basin is considered to be
high. Australia has a relatively depauperate
freshwater fish fauna by world standards
(slightly over 300 species; Allen et al. 2002). More
than 16% of these are considered to be under
conservation threat nationally (Crook 2001) and
detrimental interactions with alien species are
considered a threat to 77% of these species
(Jackson et al. 1993).
Introduction
The number of alien freshwater fish species
in Australia, their abundance, and distribution
are all continuing to steadily increase (Koehn
and Mackenzie 2004). There are now 43 alien
fish species that have been introduced into
Australia, with at least 22 species having
become established (Koehn and Mackenzie
2004). This total number of fish species is
comparable to the number of established alien
mammals (25), birds (20) amphibians (1) and
reptiles (4) combined (Bomford 2001). Seventy
four percent of fish species were introduced
for ornamental reasons, 21 % for recreational
angling and 5 % for other reasons such as
biological control. Eleven of these alien species
are now established in the Murray-Darling
Basin (from Koehn and Mackenzie 2004).
Invasive species
There are several attributes that have been
identified as important attributes of successful
invasive species (Ricciardi and Rasmussen 1998).
These attributes include: wide distributions, wide
environmental tolerances, high genetic variability,
short generation times, rapid growth, broad diet,
early sexual maturity, high reproductive capacity,
gregariousness, natural dispersal mechanisms
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.
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These can be undertaken against the criteria
outlined above after collating information on the
following areas:
•
Invasion history;
•
Biological information;
•
Environmental information;
•
Identify donors/dispersal pathways; and
•
Human activity.
A range of detailed reviews have been
undertaken for some species within the MurrayDarling Basin (see Clunie et al. 2002, Koehn and
Mackenzie 2004). Using this existing knowledge
an assessment was undertaken to determine
which of the existing established and abundant
alien species could provide the best lessons
for pest fish species management. The most
widespread species, Gambusia has received
minimal attention and, in many ways, has been
considered too hard to address as a threat.
Trout (Brown and Rainbow) are restricted
largely only to upland areas and continue to
be stocked for recreational fisheries. Goldfish
Carassius auratus, Roach Rutilus rutilus and
Tench Tinca tinca have all received minimal
attention and there is little information about
their impacts. There is, however, a considerable
volume of literature and attention that has been
focussed on carp.
Carp are the largest and most visible introduced
fish species in Australia and have a high public
profile. They have been subject to considerable
scientific study and review, both in Australia
and overseas (Hume et al. 1983; Koehn et
al. 2000). Carp have been the subject of a
series of national workshops (Murray-Darling
Association Inc 1995; Murrumbidgee Catchment
Management Committee 1994; Lapidge 2003), a
National Strategy and various policy, research
and control documents (Braysher and Barrett
2000; Carp Control Coordinating Group 2000a,
2000b), and have received considerable public
and political attention, including the formation
of a National Carp and Pest Fish Taskforce
(Murray-Darling Association Inc. 2003). Carp
were therefore considered the best species
from which to learn lessons and also provide
an example framework for the management of
other alien species.
The invasion of carp in the Murray-Darling
Basin illustrates how quickly an introduced
fish species can spread and dominate fish
communities (in numbers and biomass) in
the absence of early intervention and an
effective management strategy (see Koehn et
al. 2000). Carp have become the most abundant
large freshwater fish in southeast Australia,
now distributed over more than 1 million km2
(Koehn et al. 2000; Lintermans 2002). Carp were
introduced into Australia several times from
the mid- 1800’s but their widespread dispersal
only occurred following the introduction of
the ‘Boolara’ strain in Victoria in the 1960s.
Introduction dates for each State are as follows
(‘Boolara’ strain dates underlined) (Koehn et al.
2000): Victoria- 1859, 1960; NSW -1860s, 1970s;
ACT 1976; SA -1960, 1970s; Tas -1974, 1980,
1995; Qld -1960, 1970s. A recent invasion into
the Glenelg River catchment has expanded their
western distribution in Victoria.
Progressive steps of carp expansion in Australia
can be summarised as:
1.
Aquaculture production;
2.
Stocking into farm dams;
3.
Introduction into the Murray River;
4.
Expansion throughout Murray-Darling Basin
assisted by flooding; and
5.
Transfers to other catchments either; a) as
bait by anglers, or b) transferred by anglers to
establish new coarse fisheries.
Risk analysis
There are few detailed species-specific risk
assessments (e.g. Barlow and Lisle 1987;
Townsend and Winterbourn 1992) that predict the
future impacts of already established introduced
fish species (Arthington and Bluhdorn 1995;
Coates and Ulaiwi 1995; Clunie et al. 2002). A
retrospective risk assessment was undertaken
to examine the reasons for the successful
invasion of carp and to make predictions about
future range expansion and potential impacts
(Koehn 2004). This included: assessment of
the attributes associated with successful alien
invasive species (see above); the documented
history of spread; consideration of ecosystems
and communities; environmental condition and
trends; limiting factors and dispersal pathways.
An ecological comparison was made between
carp and native species to gain a perspective on
‘ecological closeness’ which included: maximum
size; depth position; behaviour; diet; feeding;
fecundity; environmental tolerances; habitat
specificity; habitat range; movement; dispersal;
growth; physical toughness; adaptability and
competitiveness. Climatic comparisons were
made to assess the likely climactic range
E m e r g i n g I ss u e s i n A l i e n F i s h Ma n ag e m e n t i n t h e M u r r ay Da r l i n g B a s i n – Wo r k s h op , 3 v 0 - 3 1 May 2 0 0 6
55
that carp could occupy within Australia. This
approach could be used as a basis to assess all
alien species within the Murray-Darling Basin,
including those considered in this workshop.
In summary, carp were found to have most of
the attributes of successful invasive species,
were ecologically different to most native
species across a range of different native
fish communities, and had expanded rapidly
in areas such as the Murray-Darling Basin
where habitats had already been degraded and
populations of major native fish predators had
been greatly reduced. Carp had few climatic
restrictions and were deemed capable of
invading most freshwater systems across the
remainder of the continent. The main transfer
mechanisms between basins occurred by
humans either as deliberate introductions
or use as bait. The koi aquarium trade was
identified as a serious dispersal pathway and
inter basin water transfers were identified as
another potential transfer mechanism.
Our knowledge of the biology and ecology of
many alien species, especially under Australian
conditions, is limited. Our understanding of
their impacts is rudimentary, even for direct
impacts such as predation, let alone impacts at
the community or ecosystem levels (Townsend
2003). An understanding of impacts is important
to build support for adequate alien species
management and to provide some basis for
benefit:cost analyses of management options
(Choquenot et al. 2004). Understanding impacts
is an essential component of best-practice
vertebrate pest management, which is based
on the concept of managing impacts rather
than numbers (Braysher 1993). Despite the
attention focussed on carp, their ecological
and environmental impacts are poorly defined
(Koehn et al. 2000) and remain mainly limited
to impacts on water quality (eg. Driver et al.
2005; King et al. 1997).
Discussion
A range of policy and management documents
already exist relating to alien species
management in Australia. A synthesis of
the literature (including “grey” literature),
identified current management frameworks for
invasive freshwater fish species, assessed the
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
2004). This review identified a lack of recognition
of the problem, inconsistency in legislation,
policy, and approaches across jurisdictions
and no nationally coordinated on-ground
management actions. Where legislation and
policy was available it was not always used to
good effect. The National Management Strategy
for Carp Control (NMSCC) and other documents
provide a strong framework from which to base
management of this and other alien species.
To be of any use, however, these documents
must be used and the appropriate policies and
management actions implemented.
Several legislative framework and policy
documents already exist in Victoria to implement
better pest fish management. For example:
1.
The introduction of live fish outside their natural
range is listed as a Potentially Threatening
Process under the Flora and Fauna Guarantee
Act 1992 (Scientific Advisory Committee 1992),
however, an Action Statement is required.
2.
Fish should be included in the Victorian
Pest Management - A Framework for Action
(Department of Natural Resources and
Environment 2001).
3.
Documents that underpin The Victorian River
Health Strategy (Department of Natural
Resources and Environment 2002) need to
include details of management actions for
pest fish species. Changes in the geographic
distribution of indigenous and exotic fish
species have been recommended as
environmental health indicators (Office for
the Commissioner for the Environment 1988).
Fish and alien fish species have now been
considered in other measures of river health
in the Sustainable Rivers Audit (Harris 1995;
Whittington et al. 2001; Murray-Darling Basin
Commission 2004).
Although the NMSCC relates only to one species,
it can easily be adapted to include other alien
species, as has been done in Queensland
(Department of Primary Industries, Queensland
2001), forming the basis of a national or Basinwide alien species management plan. The Action
Plan for the Murray-Darling Basin, developed for
alien species by the National Carp and Pest Fish
Taskforce, a community focussed organisation
(Murray-Darling Association Inc. 2003), could
also be expanded and incorporated into a national
strategy.
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The goal of management for alien species
is not a reduction in numbers per se, but
a reduction in the impacts caused by each
species (Lodge and Shrader-Frechette 2003)
(e.g. predation, competition, ecosystem
changes). This together with the use of pest
management principles (Braysher 1993;
Bomford and Tilzey 1997) and adoption of
integrated approaches will give the best
results. Clearly defining the problem, the
objectives and the measurables is important
before action is taken. This may require the
development of new skills and organisational
links that go beyond the traditional roles of
fisheries agencies and current management
expertise. Most transfer of alien fish between
catchments is human assisted (Lintermans
2004) and transfers by anglers have been
recognised as a major source of invasion into
new catchments both in Australia and New
Zealand (McDowall 1997; Koehn et al. 2000).
Social research and appropriate education,
management and enforcement options are
required for this issue. The lack of community
education and awareness of the threats posed
by alien fish has also been recognised. There
is a need for invasive species response squads
with the appropriate funding and tools to deal
with new incursions. The costs of alien species
both in economic and environmental terms can
be considerable, and quantification of these
using bioeconomics benefit/costs analyses (see
Choquenot et al. 2004) is needed to reinforce
the need for action.
Tools that are needed
Lessons learnt from the
prior invasion of alien
species in the MurrayDarling Basin
•
Remember carp and the cane toad
(Koehn et al. 2000; Koehn 2004; Suthurst
et al. 1996)
•
Management must limit spread.
Spread can be rapid.
•
Humans are the main transfer mechanism.
•
There is a need to incorporate social science
into pest fish management.
•
Successful and unsuccessful local eradication
efforts should be documented and learnt from.
Successful attempts should be promoted as
educational exercises.
•
Education, information exchange, awareness
and a change in public thinking is needed.
•
Key stakeholder groups need to be engagedanglers, aquarium and water industries.
•
Public pressure, media and political
support is necessary.
•
Listings and legislation help raise priorities
and legal obligations.
•
Pest fish need to be included in other planning
regimes eg. regional planning.
•
Community engagement is imperative.
•
There is a need to be serious,
committed and vigilant.
•
Preventative programs and early actions will
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.
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57
Acknowledgments
The author wishes to thank Ivor Stuart, Mark
Lintermans and Tim O’Brien for comments
on the manuscript.
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predicting ecological impacts of introduced aquatic
organisms: a case study of common carp Cyprinus
carpio L., in the Sepik-Ramu river basin, Papua New
Guinea. Fisheries Management and Ecology 2:
227-242.
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59
Risk assessment modelling to identify
potential fish invaders
Mary Bomford
Bureau of Rural Sciences,
GPO Box 858, Canberra ACT 2601.
Abstract
Risk assessment modelling can be used to help
determine which exotic fish species are most
likely to establish pest populations in the MurrayDarling Basin. Five factors are correlated with the
establishment success of exotic freshwater fish
in Australia: (1) climate match; (2) overseas range
size; (3) number of continents where the species
has established exotic populations; (4) proportion
of introduction events that have been successful
for the species; (5) proportion of introduction
events that have been successful for species in
the same genus or family. A fish species’ scores
for these five factors can be summed to give an
establishment risk score. The number of times
and places a species is released is also strongly
correlated with establishment success and most
fish species will establish exotic populations if
they are released often enough. Of the 33 exotic
fish species known to be established in the wild
in Australia, four have high climate matches to
the whole of the Murray-Darling Basin: Carp,
Mozambique tilapia, Rainbow trout and the
Guppy, and a further six to large parts of the
Basin: Sailfin molly, Platy, Tench, Goldfish,
Brown trout and Roach. The risk assessment
model predicts all ten species are highly suited
to establishing exotic populations in the MurrayDarling Basin. The model also predicts that
many other species which have not yet
established in the wild in Australia are highly
suited to establishing pest populations in the
Murray-Darling Basin should they be released
there. Some of these species are reported to
have major adverse impacts where they have
established exotic populations overseas. Risk
assessments need to be conducted on all the
exotic fish species (over 1000) that are kept and
traded in Australia so that an alert list of highrisk species can be developed. However, most
60
fish species can probably establish if they are
released enough times. Hence investment is
needed in educating the community to improve
awareness of the consequences of releasing
exotic fish.
Introduction
At least 33 species of alien freshwater fish have
successfully established exotic populations in
Australia, including at least 14 new fish species
that established between 1997–2006 (Tables 1
and 2). At least another 16 species have been
identified in Australian water bodies but are not
known to have established breeding populations
(Kailola 2000; Bomford and Glover 2004, Table 2).
Bomford and Glover (2004) developed a risk
assessment model to predict the likelihood
that exotic freshwater fish species introduced
to Australia could establish wild populations.
The Australian Government Department of
the Environment and Heritage use the risk
assessment model to help make decisions on
which species should be banned from import and
which species can be let into Australia. The States
can also use the model for making decisions
about whether to restrict trade and keeping of
exotic fish species that are already present
in Australia.
Predicting whether or not an alien species could
establish a wild population in Australia is always
subject to uncertainty. This is partly because
scientific knowledge on species invasions is
still in its early stages and no ecological models
are yet available that can make highly accurate
predictions for all species. Secondly, even if good
models are developed, there are often inadequate
data on the distribution and ecology of individual
species, and these data are required to conduct
assessments using the models. If the input data
E m e r g i n g I ss u e s i n A l i e n F i s h Ma n ag e m e n t i n t h e M u r r ay Da r l i n g B a s i n – W o r k s h op , 3 0 - 3 1 May 2 0 0 6
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
Goldfish Carassius auratus*
Green terror Aequidens rivulatus
Roach Rutilus rutilus*
Firemouth cichlid Thorichtys meeki
White-cloud mountain minnow Tanichthys albonubes
Banded cichlid Heros severus
Mosquitofish Gambusia holbrooki + affinis*
Redhead cichlid Vieja synspila
Guppy Poecilia reticulata
Blue tilapia Oreochromis aureus
One-spot live bearer Phalloceros caudimaculatus
Wami tilapia Oreochromis urolepis
Sailfin molly Poecilia latipinna
Chinook salmon Oncorhynchus tshawytscha
Platy Xiphophorus maculatus
Atlantic salmon Salmo salar*
Green swordtail Xiphophorus hellerii
Plainfin frogfish Porichthys notatus
Mozambique tilapia Oreochromis mossambicus
Japanese seabass Lateolabrax japonicus
Red devil/Midas cichlid Amphilophus citrinellus
Sobaity seabream Sparidentex hasta
Three-spot cichlid Cichlasoma trimaculatum
Common triplefin Forsterygion lapillum
Victoria Burton’s haplochromine Haplochromis burtoni
Redbanded perch Hypoplectrodes huntii
Niger cichlid Tilapia mariae
American flagfish Jordanella floridae
Oscar Astronotus ocellatus
Blue acara Aequidens pulcher
Convict cichlid Archocentrus nigrofasciatus
Jewel cichlid Hemichromis bimaculatus
Redbelly tilapia Tilapia zillii
Jack Dempsey Cichlasoma octofasciatum
Oriental weatherloach Misgurnus anguillicaudatus*
Redfin perch Perca fluviatilis*
Rainbow trout Oncorhynchus mykiss*
Brown trout Salmo trutta*
Brook trout Salvelinus fontinalis*
Three-spot gourami Trichogaster trichopterus
Yellowfin goby Acanthogobius flavimanus
Goby Acentrogobius pflaumii
Chameleon goby Tridentiger trigonocephalus
Rosy barb Puntius conchonius
Pearl cichlid Geophagus brasiliensis
* denotes species recorded in the Murray-Darling Basin.
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61
are unreliable or incomplete, the models will give
less reliable results. Some ecologists doubt that
it is possible to build accurate models to predict
the outcomes of exotic finfish introductions
because there has been so little progress in
developing generalisations about the factors
affecting the establishment and impacts of
introduced species (Ricciardi and Rasmussen
1998; Williamson 1999). Some ecologists consider
the consequences of an introduction are largely
dependent on individual circumstances (such
as timing, biotic and abiotic components of the
invaded habitat, and numbers and condition of
introduced fish) and on stochastic events, all of
which can make outcomes highly unpredictable.
Other ecologists believe that simple models,
if based on reliable data, can provide valuable
information on invasion threats in the form of
robust generalisations (Ricciardi and Rasmussen
1998; Ricciardi 2003). Kolar and Lodge (2002)
assessed exotic fish introductions to North
America and Bomford and Glover (2004) assessed
exotic fish invasions to Australia. These authors
describe general factors which do not require
expensive long-term research and can be used
for predictive risk assessments. Predictions from
these approaches may not always give complete
accuracy regarding invasion potential, but the low
cost of generating these predictions (compared to
the potentially high cost of losing endemic native
communities and species to exotics) may make
them the best available for making decisions on
the import and keeping of exotic species.
Risk assessment model
2. Overseas range size
This was calculated as the number of 1 degree
latitude by one degree longitude grid cells in
which the fish was recorded as present (either in
its natural or exotic range, excluding Australia) in
http://www.fishbase.org.
3. Exotic elsewhere
A score calculated from the number of continents
on which an exotic population of the fish has
established.
4. Introduction success rate for species
Arthington et al. (1999) recorded the number of
introduction events and the number of successful
introductions for 352 freshwater finfish species
introduced around the world. This score is based
on the proportion of introduction events for a
species that resulted in an exotic population
establishing in (Arthington et al.’s (1999)
database).
5. Introduction success rate for taxonomic
group
An analysis of data in Arthington et al.
(1999) for introduction events for finfish around
the world showed that introduction success
is strongly correlated with taxonomic group.
Some families and genera have far higher
establishment success rates than others (Table
3). This score ranks fish species according to
whether they are from families or genera with
high or low success rates in Arthington et al.’s
(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 Climate Match 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
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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
1
2
3
4
5
6
7
-20
-25
-30
-35
-40
-45
120
130
140
150
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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
Gobiidae
Cobitidae
Number of
introduction events
Number of
successful introductions
Success rate %
16
14
88
8
7
88
Poeciliidae
172
144
84
Clupeidae
10
8
80
Loricariidae
5
4
80
Atherinidae
8
6
75
Osteoglossidae
8
6
75
105
70
67
Ictaluridae
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
6
3
50
Fundulidae
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 Arthington et al.’s database are not included
in this table.
64
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Bomford and Glover (2004) used these five factors
to develop a model for assessing establishment
risk for other species that could be released
in Australia. A fish’s scores for each of the five
factors are summed to give a total Establishment
Risk Score. Figure 2 compares the Establishment
Risk Scores for exotic fish introduced to Australia
that established exotic populations with scores
for fish that have been recorded in the wild
but have failed to establish exotic populations.
Most species that failed to establish get low or
moderate Establishment Risk Scores, whereas
most fish that successfully established get
serious or extreme scores.
Number of species
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
0
≤10
11-14
15-19
≥20
Establishment risk score
Limitations to the risk
assessment model
Bomford and Glover’s (2004) model has some
limitations. Clearly the inclusion of additional
variables for a fish’s environmental threshold
tolerances, such as minimum and maximum
water temperature, minimum dissolved oxygen
content and maximum turbidity would have
been desirable. But data on these variables are
unavailable for many fish species, and these
values are not known for most Australian water
bodies either. So unfortunately it was not feasible
to include them in the model.
Ruesink (2005) found that fish in families with
small body size and fish that are omnivores also
have higher establishment success so these
two attributes could also be considered as
additional risk factors for establishment. She
also found that establishment success rose with
endemism in the recipient country’s fish fauna.
Endemism is the proportion of native species
in a country that do not occur elsewhere – and
Australia’s freshwater fish fauna is strongly
endemic (Allen et al. 2002).
often incomplete. Another potential problem
is that the overseas geographic range of a fish
may be restricted by predators, competitors or
geographic barriers and the species may actually
be capable of living under a much broader range
of climate conditions. In such cases climate
matching may well underestimate the potentially
climatically suitable areas for exotic fishes in
Australia. Further, climate is only one out of a
whole suite of factors that might influence an
exotic species’ distribution in Australia, so climate
matching cannot be expected to give entirely
accurate predictions of species’ potential ranges.
For example, although most of the MurrayDarling Basin has a climate similar to that in
places where Rainbow trout occur overseas,
this species is generally confined to cooler
upland streams and therefore may not spread
in warmer slow-flowing waters. Despite these
caveats, climate match maps give a reasonable
general picture of climatic suitability of Australian
environments. However, to get more reliable
predictions of the potential range of an exotic fish
species in Australia, it would be necessary to do
more detailed analyses than Bomford and Glover
(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
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65
The database in Arthington et al. (1999) shows
that introduction success for exotic fish is
strongly correlated with the number of release
events (Figure 3). Every species that Arthington
et al. (1999) recorded as being introduced more
than ten times established at least one exotic
population. This suggests that most fish species
can establish exotic populations if they are
released enough times. As it is not possible to
predict how many times an exotic fish species
introduced to Australia might be accidentally or
illegally released, Bomford and Glover (2004)
did not include the number of release events
(propagule pressure) as a risk factor in their
model. However, aquarium species that have
a low commercial value and are widely kept
in Australia are likely to be released more
often, and these species are therefore likely
to have a higher risk of establishing exotic
populations. Frequent releases may also
occur of species popularly used as baitfish.
Species that are valued for recreational
fishing or as food may also be illegally
released by people wanting to establish new
populations.
CjbWZgd[hjXXZhh[ja
^cigdYjXi^dcheZgheZX^Zh
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).
&%%
-%
G'2%#,-*-
+%
)%
'%
%
%
'%
)%
+%
-%
&%%
&'%
&)%
CjbWZgd[^cigdYjXi^dcZkZciheZgheZX^Zh
Applying the model to the
Murray-Darling Basin
Of the 33 exotic fish species known to be
established in the wild in Australia (Table 2),
four have a high climate match to most of the
Murray-Darling Basin: Carp, Mozambique tilapia,
Rainbow trout and the Guppy. These four species
also score an extreme Establishment Risk Score
in Bomford and Glover’s model. Another two
species that are already established in Australia
have high climate matches to the north of the
Basin (Sailfin molly and Platy), and these two
species also both have extreme Establishment
Risk Scores. Four species have high climate
matches to the south of the Basin (Tench,
Goldfish, Brown trout and Roach) and the first
three of these have an extreme Establishment
Risk Score and the Roach has a serious
Establishment Risk Score. Hence Bomford and
Glover’s model predicts all ten of these species
66
are highly suited to establishing in the MurrayDarling Basin.
The Redfin perch has an extreme Establishment
Risk Score in Bomford and Glover’s model
but only has a high climate match to the very
south eastern corner of the Murray-Darling
Basin. The Oriental weatherloach has a serious
Establishment Risk Score in Bomford and
Glover’s model but only has a fairly low climate
match to the Murray-Darling Basin. This is
probably an under-estimate of the Oriental
weatherloach’s climate match because the
overseas range for the Oriental weatherloach
given in FishBase does not include its introduced
range in America.
Two species which have been found in Australian
waters, but which are not yet known to have
established in breeding populations in Australia,
have good cimate matches to the MurrayDarling Basin. The blue tilapia has an extreme
Establishment Risk Score in Bomford and
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Glover’s model and also has moderately good
climate match to the north of the basin. The
Atlantic salmon has a serious Establishment Risk
Score and has a very high climate match to the
south of the Basin.
Fishbase lists another 27 exotic fish species that
are reported as environmental pests overseas but
which have not yet established in Australia. Five
of these species have high climate matches to
the Murray-Darling Basin and also have extreme
Establishment Risk Scores in Bomford and
Glover’s model: Bluegill Lepomis macrochirus,
Largemouth bass Micropterus salmoides, Black
bullhead Ameiurus melas, Nile tilapia Oreochromis
niloticus and Stone moroko Pseudorasbora parva.
Assessing potential impacts
Some exotic fish species are known to have
devastating impacts. For example, the exotic
Nile perch in Lake Victoria, Africa, caused the
extinction of over 200 species of native cichlid
species (Welcomme 1988).
A review of factors associated with adverse
impacts of exotic freshwater finfish shows that
reliable knowledge about impacts is sparse
(Bomford and Glover 2004). There is insufficient
reliable knowledge of the factors correlated with
impacts of exotic fish to make the development
of a quantitative model feasible for assessing
the risks of impact for new species of exotic fish
in Australia. Nonetheless, Bomford and Glover
(2004) suggest adverse impacts are most likely to
be cause by exotic freshwater finfish that:
•
have adverse impacts elsewhere;
•
have close relatives with similar behavioural
and ecological strategies that cause adverse
impacts elsewhere;
•
are generalist feeders;
•
are piscivorous;
•
destroy or modify aquatic vegetation or stir up
sediments to increase turbidity;
•
have the potential to cause physical injury;
•
harbour or transmit diseases or parasites that
are present in Australia;
•
have close relatives among Australia’s
endemic fish (hybridization, competition);
•
are known to have spread rapidly following
their release into new environments; and
•
have a good climate match to Australia
because such species are more likely to
establish over large areas so their impacts will
be spread more widely.
This list can be used to get a qualitative
assessment of the risk a fish poses of becoming a
pest if it establishes a wild population.
Management implications
There are estimated to be over 22 million exotic
fish kept in Australia, representing over 1000
different fish species (McNee 2002). Fish of many
species are frequently released into Australian
freshwater bodies. If a new species establishes
and spreads beyond a small enclosed water body,
eradication is rarely possible, and would usually
be prohibitively expensive to attempt (Bomford
and O’Brien 1995). Therefore investment is
needed in education to improve community
awareness of the consequences of releasing
exotic fish. It may also be desirable to introduce
major penalties for the illegal trade, keeping
and particularly release of exotic fish if evidence
shows this will help reduce risk of new
high risk species being introduced into the
Murray-Darling Basin.
The Australian Government Department of the
Environment and Water Resources now conducts
reasonably robust risk assessments to prevent
the introduction of new exotic fish species that
could become future pests in Australia. But
there are still over 1000 species already in
Australia for which no risk assessments have
yet been conducted. Risk assessments are
needed on all the species that are kept and
traded so that an alert list of high-risk species
can be developed (Kailola 2000). All the data
needed to use Bomford and Glover’s (2004)
risk assessment model is available in http://
www.fishbase.org. The model does not require
expert knowledge and it usually takes less than
an hour to assess a fish’s Establishment Risk
Score. Although the results generated by the
model will have a degree of uncertainty, more
detailed assessments could be conducted on
the species that get high Establishment Risk
Scores, including more accurate determinations
of their overseas ranges and history of
establishment success overseas. CLIMEX, a
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
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67
a species’ biology but would be worth doing
for species of key concern to Murray-Darling
Basin managers. The pest potential of species
that get a high Establishment Risk Score could
also be assessed by appropriately qualified
fish biologists. Species found to have both high
Establishment Risk Scores and attributes that
make them likely to be pests could be placed
on the alert list and community education
about exotic fish could focus on these species.
Regulations restricting their trade and keeping
might also be desirable.
For the 33 exotic fish species already
established in the wild in Australia, those that
pose a high to extreme risk to the MurrayDarling Basin could have some more in-depth
risk assessments conducted. But even if the
future spread and pest potential of these
established species is accurately predicted, it
is unlikely that containment efforts will prevent
their spread if conditions are suitable.
Conclusions
Although several species of exotic fish are
already considered to be pests in the
Murray-Darling Basin, many more potential
pest species are being kept in Australia. Some
of these species are likely to establish wild
populations in the Murray-Darling Basin if
appropriate preventative action is not taken
to prevent accidental or illegal releases. Most
fish species can probably establish if they are
released enough times. Therefore educating the
community about the risks of releasing exotic
fish is essential.
Risk assessments are needed to develop an
alert list for the most significant potential pest
species. It is desirable for risk assessments
to be conducted for all the exotic fish species
currently kept in Australia. Priority should be
given to those species which are widely kept and
those which have established exotic populations
elsewhere. Species which get a high score for
establishment risk and/or have attributes that
make them likely to be pests if they were to
establish in the wild could be placed on an alert
list. Community education could focus on the
risks posed by these species.
References
Allen, G.R., Midgley, S.H. & Allen. M. 2002. Field
guide to the freshwater fishes of Australia. Western
Australian Museum and CSIRO Publishing,
Collingwood, Victoria.
Arthington, A.H., Kailola, P.J. Woodland, D.J.
& Zalucki, J.M. 1999. Baseline environmental
data relevant to an evaluation of quarantine risk
potentially associated with the importation to
Australia of ornamental finfish. Report to the
Australian Quarantine and Inspection Service,
Department of Agriculture, Fisheries and Forestry,
Canberra.
Bomford, M. & Glover, J. 2004. Risk assessment
model for the import and keeping of exotic
freshwater and estuarine finfish. Bureau of Rural
Sciences, Canberra.
Bomford, M. & O’Brien, P. 1995. Eradication or
control for vertebrate pests? Wildlife Society Bulletin
23: 249–255.
FishBase http://www.fishbase.org
Kailola, P.J. 2000. Development of an alert list for
non-native freshwater fishes. Unpublished final
report to Environment Australia, Canberra.
Knapp, S., Brown, L. & Barry, S. (2006 in prep.)
Climate Software Manual. Bureau of Rural
Sciences, Canberra.
Kolar, C.S. & Lodge, D.M. 2002. Ecological
predictions and risk assessment for alien fishes in
North America. Science 298: 1233–1236.
McNee, A. 2002. A national approach to the
management of exotic fish species in the aquarium
trade: An inventory of exotic freshwater species.
Bureau of Rural Sciences, Canberra.
Ricciardi, A. & Rasmussen , J.B. 1998. Predicting
the identity and impact of future biological
invaders: a priority for aquatic resource
management. Canadian Journal of Fisheries and
Aquatic Sciences 55: 1759–1765.
Ruesink, J.L. 2005. Global analysis of factors
affecting the outcome of freshwater fish
introductions. Conservation Biology 19: 1883–1893.
Sutherst, R.W. & Maywald, G.F. 1999. CLIMEX:
predicting the effects of climate. CSIRO Publishing.
http://www.weedinfo.com.au/bk_climx.html.
Welcomme, R.L. 1988. International Introductions
of Inland Aquatic Species. Food and Agriculture
Organisation Fisheries Technical Paper 294. FAO
United Nations, Rome.
Williamson, M. 1999. Invasions. Ecography 22: 5–12.
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.
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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
across the Murray-Darling Basin. Their range
and impacts vary. Some are present in pest
proportions and further introductions are
inevitable over time. Regardless of how good
the science is, how well the technology is tested
and how thorough the awareness strategies
are, history tells us again and again that if the
community has different attitudes to pest and
alien animals or plants or does not feel engaged
or involved in the management of those aliens, it
will be difficult to implement control measures.
The most important and initial part of any
community engagement on managing alien fish
must recognise that it is people who spread
alien fish, sometimes accidentally, sometimes
out of ignorance or fear, sometimes deliberately
through callous acts, or because of poor
understanding of the impacts of these fish on
river systems.
The introduction of myxomatosis was strongly
opposed in New Zealand because of the low level
of community understanding and awareness
about the disease and the lack of clear and
accurate information to help the public develop
an informed opinion. A report concluded that the
release of this type of biological control of pests
‘will ultimately depend on an assessment done by
governments of community attitudes’.
Plans by the Pest Animal Control Cooperative
Research Centre to shoot destructive wild horses
by helicopter several years ago in the Northern
Territory had to be stopped at the last minute
because of poor community consultation.
Developing strategies to manage alien fish in the
Murray-Darling Basin by identifying community
attitudes and implementing good community
engagement about the fish and their control
methods is no different. A small but important
example was demonstrated recently. As CSIRO
investigates the potential of the Koi Herpes virus
to manage Carp, the organisation will have to
engage the animal welfare lobby to ensure it is
happy with the way the virus may actually
kill the fish.
Even though it is illegal, some people use live
alien fish for bait. This was demonstrated in
Queensland where primary school children
along the Balonne River delighted in explaining
how they used ‘native Carp’ (goldfish) as live
bait. Furthermore, unwanted aquarium fish
are unfortunately still being thoughtlessly and
illegally disposed of in our waterways.
Attitudes
Our current attitudes to alien fish have been
determined very much by our predominantly
European heritage although this may be changing
with attitudes from other cultures and countries.
I am not sure we know or understand very much
about the attitude of more recent migrants
to Australia towards fish and fishing in the
Murray-Darling Basin. However, it is encouraging
to note that some fisheries agencies are
developing brochures on Tilapia in languages
other than English.
There was a determined push by the community
in the 1990’s to rid the Basin’s waterways of
Carp. And since then, there has been significant
investment by governments and industry in
managing Carp. But while our knowledge and
information about Carp has greatly improved,
community attitudes do not seem to have
changed as dramatically as anticipated.
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69
Anecdotally, from a series of community
meetings over the past three years, reduced
rainfall, continuing drought, low water levels,
declining Carp populations and environmental
flows have now placed Carp way down on the list
of priorities of many river communities.
Carp continue to be the most widely known of
our alien fish and I suspect that community
attitudes to the other alien fish are likely to be
coloured by the Carp experience, even though
the nature of these other alien fish differ.
It is my view that the community is generally
unaware of the other alien fish in the Basin or
the threats they pose. Some are even regarded
as native as demonstrated by the mayor of a
community in southern NSW who some time
ago, proudly and publicly at a naturalisation
ceremony, hailed trout in the local stream as a
native fish.
Some of us will recall the battle several years ago
to stop the World Coarse Fishing Championships
being held in Lake Burley Griffin, only to be
told by the ACT Government that the economic
and tourism benefits far outweighed other
considerations, a decision that sends the wrong
message to the community about Carp.
We can be very amused at these anecdotes but
it indicates the challenges ahead when wanting
to control alien fish, some of whom have the
potential to make Carp look like ‘a Sunday
school picnic!’ On what evidence I can find, and
much is anecdotal, community attitudes to alien
fish certainly vary but will play a key role in
their management.
There is evidence in Queensland that Tilapia are
being actively dispersed by the community in the
same way as Carp. Tilapia is seen as a good
fish for both angling and eating. I was in a
restaurant in Adelaide recently which offered
‘Tilapia’ as a main dish. To me, this is sending
the wrong message to the community and
underlines the importance of engaging with
people, including in languages other than
English, to discuss the problem.
The community has started to notice the
alarming spread of Oriental weatherloach
along the Murray River and yet there is little
community information about this fish. There
seems to be even less focus or coordination
amongst scientists and fisheries agencies to
start to develop control strategies.
and local levels but all have approached the table
with differing attitudes and values. For example,
in the Glenelg catchment in western Victoria, the
community wanted to get rid of Carp but some
sectors wanted slightly different outcomes.
Scientists wanted to look at using native fish
as predators; the community and recreational
anglers supported that decision but saw an
opportunity to introduce Murray cod and Golden
perch in a large reservoir to create recreational
and tourism opportunities.
Agency attitudes
I believe that it is not just community attitudes
that need to be addressed. When the
Murray Darling Association was preparing a
brochure on alien fish two years ago, NSW and
Victorian fisheries agencies were worried about
our intention to clearly state that trout and Redfin
perch were alien fish. Agency staff claimed that
recreational anglers would be upset by this
but when I spoke to a couple of peak bodies on
this issue, they seemed less nervous than the
government agencies. In fact, some agreed that
trout have certainly contributed to the decline
of galaxiids, eat young native fish and compete
with some native species for food and space.
Interestingly, some representatives of the peak
fishing groups also agreed with the Native Fish
Strategy that trout need to be better managed.
Developing this brochure also identified an
ongoing debate on how to even define fish that
are not native to the Murray-Darling Basin. There
was some reluctance to identify trout and Redfin
perch as alien species even though they have
impacted significantly on some native fish and
their habitats. The aim is not to eradicate these
fish but rather manage them more effectively
and restrict their impacts where possible, a view
supported by communities that rely on trout
fishing for their economic and social benefits.
I also understand that when the MurrayDarling Basin Commission’s Native Fish
Strategy document was being prepared, some
State agencies wanted Redfin perch given less
prominence as an alien fish.
Over the last 10 years, managing Carp has
involved a lot of players and multiple stakeholder
input into management plans at national, state
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Aboriginal community
attitudes
As we look at the alien fish issue, we must also
consider and engage Indigenous communities
and acknowledge that they may also have
differing and varying attitudes.
During several discussions with the Yorta Yorta
Nation in northern Victoria, the Yorta Yorta people
made it clear that they see Carp as a problem
but they are of no commercial interest. Also, they
will not eat Carp, only bury them. Yet, in other
parts of the Murray-Darling Basin, Aboriginal
communities have made some attempts to exploit
Carp for commercial gain but with little success.
At the launch of the Invasive Animals Cooperative
Research Centre in Canberra in August 2005,
Indigenous people drew attention to the fact
that some Aboriginal communities might resist
wholesale slaughter of aliens as this type of
control is contrary to their culture. In a book on
the impacts of Carp in Australia (Koehn et al.
2000), the authors note that Indigenous people
also fear the use of biological control for alien
fish, particularly viruses. This is not only because
of their potential impact on iconic native fish
important to Aboriginal culture but because of
the deadly impact of introduced viruses and
diseases on Indigenous populations over the
past 200 years.
One thing that has become apparent is that
Aboriginal communities in the Murray-Darling
Basin see the huge numbers of Carp as denying
them the opportunity and right to catch native
fish to supplement their diet, an activity that is
firmly embedded in their culture. I suspect that
they would hold similar views on other alien fish.
And it is worth stating again that when Aboriginal
communities participate in controlling alien fish,
they need to be involved as mainstream partners,
not singular or separate entities.
Researching attitudes
I mentioned that much of what I can tell you is
anecdotal – and that is part of the problem.
We are good at raising awareness and passing
on information about alien fish. We are good at
developing control strategies. We are reasonably
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
Carp project made an attempt when it engaged a
consultant to research what was the first attempt
to quantify community attitudes to using gene
technology to manage Carp.
A key issue in researching attitudes is to first of
all identify what attitudes we are looking for. Do
we have any idea what the drivers of community
attitudes to alien fish or even native fish are?
What are the attitudes amongst governments and
researchers that may need to be challenged to
implement management programs?
Discussions at community forums about native
fish and carp indicate to me that the community
may be further ahead in its thinking about alien
fish than government agencies
It is clear to me however, that we need a review or
research project on social attitudes and reasons
as to why people continue to want to introduce
potential pest fish into Australia and why people
continue to distribute alien fish in our waterways.
The Invasive Animals Cooperative Research
Centre recently engaged a social researcher to
undertake a related study.
Do we even know what questions to ask when
seeking information about community attitudes
to alien fish, because only the right questions
will provide the right and useful answers? I am
reminded of questions put by the media to people
of NSW when the debate about using treated
effluent to help overcome water shortages. How
many times did I hear in the media the question,
“Would you drink sewage water?” Certainly a vital
and current issue, but the wrong question!
There are also changing attitudes to alien fish
that need to be kept in mind. From a number
of youth forums that the Murray Darling
Association have run over the past five years,
young people are increasingly confusing Carp
as a native species. We sometimes forget that
new generations have never seen rivers in the
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
most eaten freshwater fish in the world. A South
Australian Carp fishermen told me recently that
rising prices and shortages of more traditional
fish in Australia are making people look at Carp
as a cheap source of fish. Millions around the
globe seems to know about the nutritional and
price value of Carp as a fish - except Australians.
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Community willingness
to be involved
The responsibility for controlling alien fish rests
with the entire community of the Murray-Darling
Basin, not just researchers or governments.
Experience with Carp has shown the willingness
of the community to contribute to managing
these pests and improve opportunities for native
fish. A key to this has been the provision of good,
accurate and correct information.
As we have found with Carp, trying to manage
alien fish in isolation will not have a significant
impact on rehabilitating native fish populations.
However, an integrated approach will make a
difference managing these fish and contribute to
the success of the Native Fish Strategy.
Even referring to some alien fish as ‘pests’ can
be a problem as it may focus attention on just
getting rid of the fish and not addressing the key
issues of degraded habitats and changes to river
environments that encouraged the alien fish in
the first place.
Community engagement
It is also worth pointing out something about
community involvement. There are a number
of terms that get flung around on this topic –
community education, community awareness,
communication, community participation,
community engagement. To me, they all mean
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.
In summary
•
The community wants to be involved in
managing alien fish
•
Involvement can lead to ownership
•
Community understanding and attitudes will
affect strategies to manage alien fish
•
People are the principle means of these fish
being spread
•
There is little community knowledge on alien
fish and their impacts apart from Carp
•
Attitudes of agencies towards alien fish need
to be addressed
•
Indigenous knowledge and attitudes must be
considered
•
Information and education is not the same as
engagement
•
The key to community engagement is good,
accurate and up-to-date information
•
Engagement may need to be in languages
other than English
•
Remote communities should not be ignored
because of isolation
•
There is an urgent need to research
community attitudes to alien fish.
References
Koehn, J.D., Brumley, A.R. & Gehrke, P.C. 2000.
Managing the impacts of carp. Bureau of Rural
Sciences, Canberra.
Also, even though people will want to be involved,
they will want to participate at various levels and
capacities.
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List of participants
Dean Ansell
Murray-Darling Basin Commission
Adrian Harvey
Rural Solutions SA
Natalie Baker
Queensland Department of Primary
Industries and Fisheries
Sarah Hatch
Department of the Environment
and Heritage
Bill Bardsley
New South Wales Department
of Primary Industries
Jason Higham
Rural Solutions SA
Plaxy Barratt
Queensland Murray Darling Committee - Border
Rivers Catchment Management
and Landcare
Jim Barrett
Murray-Darling Basin Commission
Keith Bell
K&C Fisheries Global Pty Ltd
Mary Bomford
Bureau of Rural Sciences
Ben Bowman
Department of Primary Industries Fisheries Victoria
Michael Hutchison
Queensland Department of Primary
Industries and Fisheries
Peter Jackson
Queensland Department of Primary
Industries and Fisheries
Frank Keenan
Department of Natural Resources
and Mines
Peter Kind
Queensland Department of Primary
Industries and Fisheries
John Koehn
Arthur Rylah Institute
Craig Boys
Murray-Darling Basin Commission
Brian Kuhn
Nobby & District Fishing Club
Mike Braysher
University of Canberra
Chris Kuhn
Nobby & District Fishing Club
Lindsay Chadderton
New Zealand Department of Conservation
Ron Lewis
Native Fish Australia
Wayne Fulton
Primary Industries Research Victoria
Mark Lintermans
Environment ACT
Alice Fistr
Primary Industires and Resources
South Australia
Adam Logan
Queensland Murray Darling Committee Inc
Dean Gilligan
New South Wales Department
of Primary Industries
Natasha Grainger
Department of Conservation
Ivor Growns
New South Wales Department
of Natural Resources
Michael Hammer
Aquasave Consulting
John Harris
Harris Research
Alex McNee
Bureau of Rural Sciences
Damian McRae
Australian Government Department
of Environment and Heritage
Andrew Norris
Invasive Animals CRC
Malcolm Pearce
Queensland Department of Primary
Industries and Fisheries
Tarmo Raadik
Arthur Rylah Institute
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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
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Emerging Issues in Alien Fish Management in the Murray-Darling Basin Statement, recommendations and supporting papers
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