23/5/06
Fisheries officers are working around the clock to identify and contain what may be a mutated feral fish found in one of Perth's urban waterways.
Fisheries Minister Jon Ford said the exotic fish, thought to be from the Cichlid family, had been found at Bennett Brook near Guildford and if allowed to spread, could devastate Perth's river systems, including the Swan and Canning Rivers.
"This species of fish has been described as the cane toad of the waterways and has the potential to wreak havoc on our native fish populations and rivers," Mr Ford said.
"In other States, species from the Cichlid family like the tilapia, as well as introduced carp in the Murray-Darling river system, have devastated waterways to the point that native species may never recover.
"There is one case where a few of these ruthless predators were released into a golf course pond in the Eastern States and within months, authorities were forced to poison the water and remove 16 tonnes of these killers.
"The Cichlid family is known to produce hybrid species and if this infestation is not contained and eradicated, we may lose whole populations of native species in and around our waterways."
Scientists at the Department of Fisheries will use electrofishing techniques this week to try to identify the species, although it will be several days before the results of a taxonomic assessment will be known.
Electrofishing is a capture-and-release method used to obtain population estimates, length-weight relationships and age and growth, to determine the extent of the incursion and obtain samples for study.
Cichlids are popular aquarium fish in Western Australia, but like all feral or exotic species, should never be released into waterways, as they may compete with native species and destroy delicate aquatic ecosystems.
"We may never establish how these fish entered our waterways but I urge the public to take extreme care when disposing of any exotic fish," the Minister said.
"This should serve as a serious wake-up call to all of us that we must never, ever flush fish down the toilet or release them into our waterways and rivers."
Mr Ford said a firm identification of the species would assist in the development of a response plan.
"Once the identity of the fish is known, we will be in a better position to predict the potential impacts and threats to native species," he said.
"Department of Fisheries scientists specialising in freshwater fish and fish health are now analysing frozen samples to obtain more information about presence of parasites, reproduction, diet, age and growth and are also conducting water temperature survival tests to determine if this suspected tropical species can survive a Perth winter.
"The Carpenter Government is committed to protecting our unique environment and I urge the public to be ever-vigilant in protecting our waterways from the threat of introduced feral species."
The Department of Fisheries is operating a telephone hotline for callers to report sightings of the Cichlid or any other suspected exotic species in waterways. The number to call is: (08) 9432 8029.
Further information about feral fish and a photograph of the suspected Cichlid found at Bennett Brook can be obtained from the Department of Fisheries website at http://www.fish.wa.gov.au
The Department of Fisheries is the lead agency and is partnered by the City of Swan, Swan River Trust, Department of Water, Recfishwest and the North Metro Catchment Group.
Minister's office: 9213 7200
