Virus May Control Carp The Australian River Rabbit

Geelong, Australia (SPX) Sep 11, 2006
Researchers at CSIRO Livestock Industries' Australian Animal Health Laboratory (AAHL) in Geelong - with the Department of Primary Industries Victoria - are investigating Koi herpesvirus as a means of controlling the introduced fish.
Project leader Dr Mark Crane says the virus, which first emerged in Israel in 1998, caused mass mortalities in carp in the US, the UK, Israel, the Netherlands, Japan and Indonesia. So far the virus does not appear to have reached Australia.

Supported with $355,000 from the newly formed Invasive Animals Cooperative Research Centre and the Murray-Darling Basin Commission, the two-year project will investigate the effectiveness of Koi herpesvirus in controlling strains of carp present in Australia and will examine whether the virus will have any impact on certain native fauna.

Dr Crane says while carp are a valuable resource in Asian countries, in Australia the fish is generally viewed as a major pest.

"Given their reproductive capacity and their hardiness, carp have been termed the 'rabbit of the river'."

Carp were introduced into Australia in the early 1900s as a food and sporting fish. During extensive flooding in the 1970s the fish escaped from farm dams and took over the waterways. They can tolerate a wide range of water temperatures, salinity and pH levels. Carp can also survive and breed in polluted, poorly oxygenated water.

"The fish grow to up to 20 kilograms or more in weight and each female can lay up to three million eggs in a single season," Dr Crane says. "In some areas of south-eastern Australia carp make up more than 85 per cent of the fish in the rivers and creeks.

"The virus works by attacking the carp's gills as well as other vital organs and eventually killing its host. Koi herpesvirus is attractive as a biological control agent as overseas studies suggest that it has a very limited host range, infecting only carp.

"If the laboratory studies show promise, the next step will be extensive government, public and industry consultation to determine the best course of action to control carp, while protecting and restoring Australia's valuable waterways," Dr Crane says.

The project is part of a larger pest fish control program under the Invasive Animals CRC and 50-year Native Fish Strategy at the Murray-Darling Basin Commission. Other technologies being developed in the pest fish program include 'daughterless' technology, carp-specific biocides, pheromone and sensory attractants.

"It is anticipated that if these technologies are proven to be effective and safe, they will be applied on-ground in an integrated pest fish control program for the Murray-Darling Basin," Dr Crane says.

Why do I hear alarm bells?

Why don't they just hold worl championships there and all the fish caught can be humanly dispacted instead of returned. They would then slowly empty the rivers etc.

Introducing a virus is a very dangeous game. These are the same experts that said it would be safe to farm the carp in the first place.

I think its a good idea! I sort of like the idea of introducing a virus to help control the number of introduced fish.

No doubt they will take some time to research the disease to ensure that it cant affect other species.

As for removing them by rod and line...get real! they breed faster than they can be caught! Even if they had a "World Carp championships" every week.

No I reckon good luck to them and whatever they decide to do in THEIR country.

It was said a bit tongur in cheek Budgie. Obviously you could never empty the water by rod and line.

A virus though may not effect the native species to start but we all now how they can mutate. then there fighting a all new problem.

The world is growing short of fishmeal ect. Surley there is a good source there.

This attempt shows a short sightedness that borders on madness. No virus or disease ever eradicates a species (or at least unlikely to). Those that are resistant to it survive and repopulate, and you're back to square one as was the case with rabbits; 100 million in 1950 down to one million after myxamatosis now back to 35 million and climbing (excuse spelling on mxy?). Will they never learn? Similarly those whose ancestors survived black death retain resistance to AIDS through their inherited genes.

So whats the answer then? How can the Aussies redress the damage done so long ago by introducing this non indigenous species?

I do agree that maybe they could be opening yet another can of worms though!Trouble is though that once man has interfered with nature often the only way to return things is for him to intervene again.

Sad thing is we dont seem to learn do we?

so the solution to their carp problem is to introduce a virus which has never been there.

therefore it has never encountered any of the other factors which could cause it to mutate and become fatal to all other fish species in australia.
oh well

no worries mate.

And I dont suppose theyve thought about that then...................

probably, but they cant test it without sticking the virus out in the wild, you can simulate it in a laboratory, but there will be some thing they miss.

how for example would they account for indigenous fish with genetic immunities to various local viral factors or even a typhoid mary type scenario for every indigenous viral factor.

it only needs one combination to potentially wipe out every fish in oz.

The only way to completely kill them of is to wipe-out everything in the watercourse then repopulate the indigenous species.

As no other method is 100% but i am sure this to would be unacceptable to local environmentalist.

Good points raised.It will certainly be interesting to observe the out come if they do go ahead.