By Dr Ken McColl, CSIRO and Matt Barwick, National Carp Control Plan – 5th March 2018
A small collective of scientists have recently published a letter in the journal Science. The lead author Jonathan Marshall and his colleagues questioned if the carp virus would work on carp in Australia, and called for further assessments to provide convincing evidence that biocontrol can achieve sustainable reductions in carp populations, without harming native ecosystems.
The main points made by the authors of this correspondence are:
- the presence of different strains of carp in Australian waters may confer resistance;
- carp infected with the carp virus have been observed to change behaviour, seeking out water temperatures that are sub-optimal for CyHV-3 infection, which may reduce overall virus effectiveness;
- it is possible that the carp virus may already be present in Australia. If so, this is likely to reduce efficacy of the virus.
Those working on the National Carp Control Plan are collectively aware of these concerns. In fact, these questions are among those that have shaped the research now underway and proposed under the National Carp Control Plan. CSIRO researchers are currently conducting epidemiological modelling that considers how various factors – including temperature and carp behaviour – are likely to influence effectiveness. Those results will be central to developing an overall strategy on if and how a potential release of the carp virus might work.
CSIRO researchers have also proposed to expand work conducted to date to double-check if the carp virus is already in Australian carp populations, and whether it could cross-react with other viruses. In addition, they will examine genetic variation of carp in Australian waterways, to better understand risks of resistance to the virus emerging in treated carp populations. Additional studies will examine the potential impacts on aquatic ecology, water management, social science and human health.
We welcome robust discussion on Australia’s efforts to explore options for the control of carp impacts in Australia, and the prominence of the journal that this letter appears in will help to elevate this discussion appropriately. Fortunately, this correspondence appears to re-affirm that we are on the right track, and asking the right questions.
Learn more about the National Carp Control Plan at www.carp.gov.au
(featured image supplied by Danswell Starrs)