Carp herpes virus might end in anti-climax

By Country News

Carp culling plans continue to make a splash, as experts warn infecting the species with a herpes virus will only provide a short-term solution.

University of Sydney’s Associate Professor Joy Becker from the School of Life Environmental Sciences, along with Professor Michael Ward and Dr Paul Hick from the School of Veterinary Science, say the likelihood of carp populations being controlled by releasing the virus is significantly reduced because of herd immunity and the carp’s ‘‘remarkable fecundity’’.

On May 1, 2016, the Federal Government announced a $15 million investment over two-and-a-half years to develop the National Carp Control Plan.

The purpose of this initiative was to undertake further research, approvals, and consultation to develop a comprehensive plan for a potential release of Cyprinid herpesvirus (carp herpesvirus) by the end of this year.

Dr Becker — who is a member of the NCCP Scientific Advisory Group — says this initiative could be a one-hit wonder.

‘‘The release of this herpes virus in our waterways will undoubtedly cause a single epidemic of herpesvirus disease resulting in massive deaths among carp,’’ Dr Becker said.

‘‘However, there’s little evidence to suggest that we will see repeated outbreaks of a magnitude to counter the reproductive potential of the surviving carp.’’

This conclusion is based on a review of evidence from around the world examining the impact of the koi herpesvirus (CyHV3) on common carp in natural and farmed environments.

The research team’s concern is how quickly the CyHV3 virus reaches balance in host populations, which occurred within two years in a study in Japan.

Carp have a major negative impact on water quality and the value of our freshwater rivers and lakes.

This affects all water users, including irrigators and regional communities, as well as having a devastating impact on biodiversity.

Carp dominate the Murray-Darling Basin, making up 80 to 90 per cent of the fish biomass and have an estimated national economic impact of up to $500 million per year.

The NCCP is leading a $10.2 million planning process to inform decision-making on whether additional work is required and to inform on future options for carp control in Australia.

Recommendations are set to be delivered by the end of next year.