Plan to control carp population using herpes virus could ultimately fail, research shows

“Carp orgies” would spread herpes to wipe out the aquatic pest – but after suspected plagues of rotting fish and rivers of blood, the survivors will emerge immune to the virus and simply repopulate the Murray, research warns.

• Carp plague to remain another year as cull is delayed

Herpes would kill off most of the Murray’s carp but the immune fish left behind would restock the river, research shows.

Carp are notoriously fertile and engage in “carp orgies” which would spread the herpes at first, but then would just breed more immune fish.

The Federal Government is hoping to release the herpes virus into the system to get rid of the pest fish, allowing native species and plants to recover.

However, the plan has been plagued by concerns of tonnes of rotting fish and rivers of blood.

Now, Sydney University Associate Professor Joy Becker – who is also a scientific adviser on the project – has found the herpes plan would only work for a short time.

“The release of this herpes virus in our waterways will undoubtedly cause a single epidemic of herpes virus disease resulting in massive deaths among carp,” she said yesterday.

“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.”

Deputy Prime Minister Barnaby Joyce, right, with “Carpinator” Matt Barwick and a carp, left.

As well as the immunity, low water temperatures could stop the virus from spreading.

Assoc Prof Becker is on the National Carp Control Program Scientific Advisory Group and her research, a review of global evidence, has been published in Australian Zoologist.

The article says that herd immunity will mean a critical mass of the remaining carp are resistant to the virus, and their “remarkable fecundity” means the program will likely fail.

She has told the NCCP, which is in charge of the $15 million scheme, the bad news.

Just as the research was being published, former Agriculture Minister Barnaby Joyce reportedly called for the herpes virus to be released straightaway.

The NCCP is working away on a solution to the carp infestation, and trying to find out what the herpes virus would do. That is an ongoing process and the NCCP says the release of the virus is not a foregone solution if it cannot be done effectively and safely.

In July, a range of experts told Parliament the mass culling could turn the water into a sewage-like sludge, and that they would leak blood into the water before they died.

There is work underway at SA Water to determine any effect on water quality.

The “Carpinator”, Matt Barwick, is co-ordinating the NCCP and has consistently said no decisions have been made yet.