CSIRO scientists are considering the possibility that Australia's worst freshwater pest, the carp, could be programmed to self-destruct, as part of a long-term control program.

Though researchers caution that it will take more than a decade to develop satisfactory solutions to the carp plague, a recent scientific workshop pointed to several exciting scientific prospects.

One of these is to breed into the carp population a "self-destruct" gene which could be triggered by feeding the fish a special dietary ingredient, Dr Jane Roberts of CSIRO's Division of Water Resources says. This has the advantage of being totally safe for all other forms of aquatic life.

Another option is to immunise the carp against their own reproductive processes. This is a spinoff of leading-edge research now being carried out to curb the fertility of rabbits, foxes and mice, says Dr Lyn Hinds of the Cooperative Research Centre for Biological Control of Vertebrate Pest Populations, at the CSIRO Division of Wildlife and Ecology.

Researchers have virtually ruled out the idea of using a carp virus to control the pest because of doubtful efficacy and the massive testing needed to ensure it did not affect other aquatic species.

The management of Australian rivers must be improved, said Dr Roberts, which could also adversely affect carp, though this might be costly. "Finding a solution to the carp is not going to be swift," she said. "No-one has ever successfully controlled a fish pest before, and if we manage it, it will be a world first.

"At present we think it will take about 20 years -- to identify a technology, test it, get it right, and then for it to take effect. We certainly can't promise a carp-free Australia by 2000."

The CSIRO carp research program is being carried out with strong support from the Murray-Darling Basin Commission, the Federal Department of Primary Industries and Energy and state authorities.

More information from: Dr Jane Roberts 069 601 571 Dr Lyn Hinds 06 242 1729