Early research indicates the carp herpes virus would have the desired impact and reduce populations of our most damaging pest fish.
That's according to the head of the National Carp Control Plan Jamie Allnut, who leads a $10 million investigation into the safety and feasibility of introducing the fatal virus.
In a situation similar to the release of the rabbit Myxomatosis virus, carp herpes virus could significantly knock down carp numbers in targeted stretches of waterway.
But despite some bombastic rhetoric from Canberra when the scheme was introduced in late 2017, the herpes virus was never going to eradicate carp.
Its value lies in creating a window in time where projects to boost the health of rivers and native fish can be more effective than they would be with unconstrained carp populations.
"The way we will present it to government is as a window of opportunity for us to start on the journey to restore natural values. But it doesn't mean we will eradicate carp," Mr Allnut said.
Carp have decimated native fish since the 1950s and populations have exploded across the Murray Darling Basin to account for more than 80 per cent of aquatic biomass.
The 'rabbits of the waterways' out-breed natives, eatitheir spawn, crowd native fish from their habitat, reduce water quality and disrupt the entire ecosystem.
Estimates place the economic value of damage to environment, social and economic assets at more than $500 million.
"You can never know exactly how effective the virus will be, but we are building confidence it will be effective under certain conditions," Mr Allnut said.
Mr Allnut said his job was to assess the risks of releasing the virus and advise the federal government, which will be responsible for deciding to pull the trigger or not.
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The Carp Control Plan will deliver its report to the federal Agriculture Department, but a number of other departments will share oversight of the assessment.
There are legal requirements under the Biocontrol and Environment Protection Biodiversity Conservation Acts, as well as a requirement for an approval by the Australian Pesticides Veterinary Medicines Agency.
Mr Allnut said the epidemiology, or study of how a virus works, showed it was effective when three factors were in play - the carp were under stress, the water temperature was between 16 to 28 degrees celsius, and the virus was transmitted through skin to skin contact.
That means the virus would be effective from the end of winter through to summer and be most effective during springtime breeding.
The release would most likely be targeted to rivers where carp populations are above the 100kg per hectare density, which is mostly in the Southern Murray Darling Basin, but the virus would likely spread to the Northern Basin over time, Mr Allnut said.
"A lot of areas in the Murray Darling Basin the carp density is between 100 kilograms and 150KG per hectare. We worked out that it's that amount of carp has impacts on waterways, and especially native fish.
"The epidemiology says we will knock carp down when they are over the 100kg/ha density threshold, but we won't necessarily deploy the virus when the density is below that threshold.
"So population density tells us where to target carp control at a national level. It's the first time we've come up with a national map of where and in what density carp are present, but there are a lot more steps to go about predicting where the release spots would be."
The virus release would have a swift effective in the stretch of river it was released into, but would over time spread further afield.
Mr Allnut said the virus would have a "significant knock-down effect" on populations in its first year, but could create up to a 10 year window for environment projects.
The question of what to do with the tonnes of rotting carp carcases that would litter waterways after the virus takes hold has exercise scientists and local communities since the carp control plan was announced in late 2017.
Mr Allnut said target deployment of the virus would mean clean-up efforts could be managed more effectively than if there were a wider-scale deployment.
Dr Luiz Silva from Charles Sturt University led a team of researchers who looked at the clean up task.
"There are two important phases to cleaning up a mass fish kill. The first may seem obvious and easy removing the fish from the water, however in a country as large as Australia with remote regions this could be quite a challenge. Then there is a need to dispose of the carcasses appropriately and safely" Mr Silva said.
"Because the carp virus release is only a concept at this stage (requiring government approval) it represents an opportunity to develop a well thought-out clean-up and disposal plan beforehand."
Researchers recommended clean-up trials to investigate the efficiency of different strategies in different ecosystems
