29-04-2025
Aussie MP says it's 'time to release the virus' as invasive species takes over
An Aussie MP believes it's "time to release the virus" that could kill up to 80 per cent of the total population of one fish species found in waterways throughout the country.
Carp is an invasive species found in every state and territory except the Northern Territory, with populations skyrocketing thanks to flooding events and their lack of natural predators in Australian waterways. The problem has gotten so out of hand that experts now fear a lack of intervention could threaten native fish and public health — and even the Aussie way of life in some badly affected regions.
MP Helen Dalton, an independent representing the regional NSW district of Murray, is in favour of authorities releasing the carp virus (Cyprinid herpesvirus 3) which is proven to cause a fatal disease in the fish. Dalton believes the biological control method is the only way to reduce carp "dominance" in our waterways.
"Carp are having a huge impact on their environment and ecosystems," Dalton told Yahoo News. "Ninety per cent of biomass in an infected river is carp... the water is very murky and you can't see the bottom of it."
As waterways are inundated with more and more carp, river beds are being "dug up" by the fish as they search for food. This in turn completely alters the ecosystems that inhabit the river system.
"They're bottom feeders and they eat aquatic weeds," Dalton explained. "These weeds usually filter the water and do a good job of that, but if they're taken out, the water isn't filtered and we're seeing the proliferation of blue-green algae blooms."
Blue-green algae blooms already naturally exist in Aussie waterways but an increase in the bacteria subsequently results in a heightened production of its toxins. These toxins are harmful to humans and animals and can cause skin irritation and gastrointestinal issues. In severe cases, liver or nerve damage can occur.
"I'm a farmer and if I allow my stock to drink from a waterway that's got a blue-green algae bloom in it, it'll kill them," Dalton said, adding that Aussies would be warned to stop swimming and fishing in waterways contaminated by the algae blooms. "We need the virus to combat the rise of carp that is setting off this damage."
The primary concern against releasing the carp virus into waterways is the impact it will have on other wildlife, with the control plan not yet approved by authorities.
The National Carp Control Plan (NCCP), led by the Fisheries Research and Development Corporation, has undergone research and analysis into the virus but some within the industry are still very hesitant to deploy it.
Gerry Morsman, a fishing tackle rep across New South Wales and Victoria, said he's recently noticed "heaps" of the fish in rivers and, despite understanding they're a problem to deal with, he's not sure the virus is the solution.
"I am not for it at all," Gerry told Yahoo News earlier this month. "They say it'll only kill the carp but it's a big risk."
However Dalton claims the federal government is preparing for the virus to be a feasible control method, and told Yahoo News that "many scientists say it'll only impact carp".
"It won't spread into other species. I think there's been enough research [to prove that]," she said.
The Invasive Species Council (ISC) also spoke to Yahoo News this week about the virus being used to reduce carp species, expressing support for its use in population control. Dr Carol Booth, ISC's Policy Director, explained the virus is naturally occurring and it is not known to harm other fish species.
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