Common or European carp (Cyprinus carpio) is an invasive freshwater species that has been established across Australia’s inland waters for several decades. Their large mouths and feeding style contribute to their environmental damage.
Carp populations can also increase quickly with their numbers fluctuating in response to changing breeding conditions associated with seasonal rainfall.
In some river systems, carp can make up as much as 90% of total biomass, outcompeting native fish. Their high abundance increases water turbidity, damages aquatic plants, and degrades freshwater ecosystems.
Carp are now in every state and territory in Australia except the Northern Territory.
A virus that kills carp may help
The day-to-day management of carp is the responsibility of the state and territory governments. Management programs include carp removal, native fish re-stocking, installing barriers, electrofishing, and trapping.
These methods are currently not enough to reduce carp numbers. More methods are needed to help reduce carp numbers.
A virus affecting carp, Cyprinid herpesvirus 3, is present in overseas carp populations and causes a fatal disease.
Australian researchers are now looking at using this virus to assist managing carp populations. This type of solution is "biological control" or "biocontrol". Before we can use the virus in Australia, we must be sure that it will not harm native fish or Australia’s ecosystems.
Previous research to understand the virus
In Australia, viruses must undergo testing before they are used as biological control agents.
A program of carp virus research called the National Carp Control Plan (NCCP) was completed in 2022. The NCCP final report, published in November 2022, is a huge volume of high-quality research and analysis.
The NCCP was led by Fisheries Research and Development Corporation. It included specialised virus research, consultation and investigations.
The NCCP report suggests the carp virus could reduce Australian carp populations by up to 60%. It also identified questions about the impact of the virus on the environment. More research was recommended before a decision to use the virus could be made.
The current program of carp virus research
In 2023, Australian Agriculture Ministers agreed to do more research into controlling carp. This work is part of the Carp Biological Control Program (CBCP) and follows the National Carp Control Plan.
The new program includes seven Priority Research Actions (PRAs) being delivered in two batches.
Batch 1 research looks at whether releasing a carp virus could be done safely and effectively. This work is underway and is expected to finish in mid 2027.
Batch 1 research includes:
- PRA 1 - Non-target species infection susceptibility: Further testing of four additional fish species to confirm that the carp virus only affects carp and does not pose a risk to native or non target species.
- PRA 2 - Environmental impacts: Assessing potential impacts on vulnerable species, aquatic communities and river systems, including ecosystem level effects.
- PRA 3 - Virus transmissibility: Investigating ecological factors that influence virus transmissibility in carp.
- PRA 4 - Virus effectiveness: Investigating ecological factors that influence virus effectiveness in carp in the river systems.
- PRA 6 - Epidemiological modelling: Verifying and refining epidemiological modelling to better predict how the virus may spread and perform in Australian waterways.
Batch 1 research is being delivered by leading Australian research institutions, including the Elizabeth Macarthur Agricultural Institute, the Goyder Institute for Water Research (University of Adelaide) and CSIRO, under the coordination of the Department of Agriculture, Fisheries and Forestry.
Batch 2 research will explore operational feasibility of carp virus release against the following PRAs:
• PRA 5 - Cost-benefit analysis: Undertake a cost-benefit analysis to determine the feasibility of the carp virus biological control program. Develop cost-benefit scenarios for virus biological control and re-evaluate costings for virus biological control (implementation) regional NCCP case-studies incorporating more recent learnings from fish kills.
• PRA 7 - Integrated carp management methods: will inform management strategies that combine carp virus release with other control measures to support virus release and to manage risks to an acceptable level. PRA 7 will turn these findings into practical approaches and provide insights for long-term carp control and river health. This research will consider using conventional carp control methods together with the carp virus.
Batch 2 research is partially dependent on the outcomes of Batch 1 and is planned to begin in late 2026 parallel to implementation planning. Batch 2 research will strengthen implementation feasibility and decision making.
When completed, PRAs 1-7 will improve knowledge and understanding of the carp virus for use as a biological control agent and will support regulatory assessments.
The research will be guided by the Carp Scientific Advisory Group (Carp SAG) - a committee of Australian and international subject matter experts. The committee meets regularly to guide research requirements and to interpret research results.
Updates will be provided as each PRA activity is finished.
To find out more visit the Carp Biological Control Program Updates page.
Regulatory assessment and ministerial decision-making
The environmental release of the virus cannot proceed without legally required assessments and approvals from Commonwealth regulators. Regulatory assessments consider the risks, benefits, safety, and effectiveness of releasing the virus. These assessments make sure that the virus is safe to use and will deliver valued benefit. It also ensures that planning is in place to minimise and manage any potential risks.
Regulatory officials will conduct assessments in compliance with the following legislation:
- Agricultural and Veterinary Chemicals Code Act 1994
- Biosecurity Act 2015
- Biological Control Act 1984
- Environment Protection and Biodiversity Conservation Act 1999
Factors concerning carp impacts and the use of the carp virus that will be assessed by the Commonwealth regulators include:
- Human health and safety
- Protected species, ecological communities, and ecosystems
- Specificity of the virus to only infect carp
- Production of the virus
- Environmental impacts from large numbers of carp carcasses
- Magnitude of damage caused by carp
- Effectiveness of virus to kill carp
- Expected environmental benefit
Arrangements are in place to coordinate and support regulatory approval applications across the relevant Commonwealth agencies, with the aim of streamlining and expediting the regulatory assessment process.
The final decision on whether the carp virus may be used as a biological control agent will be made collectively by the Commonwealth and state and territory agriculture ministers. In addition, individual states and territories will be required to obtain any necessary local approvals prior to any release of the virus within their jurisdictions.
Carp Biological Control Program management
The Environmental Biosecurity Office will manage the program of research and submissions to the regulators.
The Carp Scientific Advisory Group (Carp SAG),the Environment and Invasives Committee (EIC) and the Carp Virus Implementation Planning Advisory Group (Carp Virus IPAG) will provide technical advice.
The Agriculture Ministers’ Meeting will oversee the CBCP.
Releasing and using the virus in Australia to control carp in our rivers is dependent on several crucial steps including:
- Satisfactory completion of scientific research
- Commonwealth regulatory agency approvals
- State and territory regulatory approvals
- Implementation planning
- Community consultation
- Agreement from state, territory and Commonwealth Agriculture Ministers.
Cost and timeline of the Carp Biological Control Program
In 2016, the Commonwealth allocated $15.2 million to investigate the feasibility of using the carp virus in Australia. The funds paid for:
- The National Carp Control Plan (2016-2022) program.
- Publishing the National Carp Control Plan (NCCP) report (2022).
- Support a smaller program of additional research Carp Biological Control Program (CBCP) to answer questions identified in the NCCP.
The AMM is expected to decide in 2028 whether the virus can be used in Australian rivers, after research is completed and regulatory approvals are in place.
Field trial
Field trials using live carp virus have been proposed in the past but are not required for regulatory assessment or approval. A field trial would also necessitate separate approval processes, with considerable time and cost implications. Nevertheless, field trials are supported as the first stage before broadscale release, subject to all required approvals.
Stakeholder consultation
Stakeholder consultation will continue, with regular updates and ongoing opportunities for stakeholders to provide feedback. This information will be shared through a range of stakeholder networks.
You can register for updates through the Environmental Biosecurity Office.
Find out more
- Get Carp Biological Control Program Updates.
- Read The National Carp Control Plan.
- Watch the 2025 webinar Update on the Carp Biological Control Program
- Watch the 2024 webinar The next phase for carp biocontrol.
Contact
Email: carp@aff.gov.au