Millions of Lake Burley Griffin carp face swift death from cyprinid herpesvirus release
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Millions of Lake Burley Griffin carp face swift death from cyprinid herpesvirus release

Picture masses of mud-sucking carp, dead, bloated and rising in greeny-yellow heaps, bobbing along the edges of Lake Burley Griffin, Lake Ginninderra and Lake Tuggeranong.

Scientists are confident cyprinid herpesvirus, commonly known as carp herpesvirus, will kill 70 to 80 per cent of Canberra's infamous carp.

Charlie Diedo has caught and released hundreds of carp in Lake Burley Griffin.

Charlie Diedo has caught and released hundreds of carp in Lake Burley Griffin. Credit:Jay Cronan

Last month federal Science Minister Christopher Pyne said hundreds of thousands, if not millions of tonnes of carp would die suddenly in the River Murray when the virus was released in 2018.

Scientists say the virus will spread swiftly. A divisive step within the fishing community, critics have warned a sudden deluge of dead fish will draw all the oxygen from the water while decomposing, killing native fish.

Senior fisheries manager Matt Barwick is confident scientists will have the means by 2018 to save Canberra from stinking to high heaven during one of the largest ecological clean-ups in generations.

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From the NSW Department of Primary Industries, Mr Barwick says it is essential to manage the millions of carp that succumb to the virus. He says scientists must first estimate the total weight of the dead carp.

"The most important thing is to understand the scale of it and resource the job appropriately," he said.

Anglers have an idea of Lake Burley Griffin's carp population. In 2012 during a weekend coarseangling tournament more than 3500 kilograms of carp were caught and released in Canberra. Previous carp competitions have filled skip bins with rotting fish.

Mr Barwick says the virus is found in 33 countries around the world, and some countries have dealt with large fish kills, including Lake Biwa, Japan, 14 times the size of Sydney Harbour.

"They lost 70 per cent of their carp population in two weeks. It took a fairly modest workforce and a few weeks to clean up the biomass using low-tech approaches," he said.

Another example was Lake Chautauqua, New York, many times bigger than Sydney Harbour, where teams of four people worked from flat-bottomed punts around the clock for a fortnight to have the water cleared of a huge kill, in readiness for the holiday season.

Canberra ecologist and a long-time fishing commentator, Dr Bryan Pratt, says two schools of thought prevail in the ACT on the issue.

One is that a dead carp is a good carp. The other is what happens to the food supply – baby carp – for Murray cod and golden perch. Researchers say the carp grow so quickly native fish rely on other food sources.

Dr Pratt supports the virus release.

"If and when the carp are removed, we will get to see whether it is the carp that are responsible for all the maladies in the rivers, or general land management is at fault as well," he said.