By Candice Boyle
AUTOPSIES on fish caught in Hobsons and Port Phillip bays have been unable to find the cause of mystery lesions found on a range of species.
Fishing enthusiasts across the West have been warned to pay attention to their catch following reports of the affected fish.
Environmental Protection Agency (EPA) Victoria and the Department of Primary Industries (DPI) are investigating reports of several species of fish, including flathead, blowfish, whiting and trevally bearing the lesions caught across a large area.
EPA executive director regional services Bruce Dawson said flathead samples had been gathered for autopsy and analysis.
As a precautionary measure the Department of Human Services has advised people to avoid touching or eating any fish that have lesions, are lethargic or look unwell.
Mr Dawson said reports indicated the affected fish were being caught in a large area from Port Melbourne through to Werribee South.
“Initial pathology results on the first samples have proven inconclusive, however, further results are expected later this week,” he said.
Mr Dawson said water samples had shown no indication of algal bloom conditions and there was no evidence to suggest that was a contributing factor.
DPI spokesman Peter Appleford said results from the analysis might prove inconclusive, but it was possible it was a naturally occurring event.
“We have seen events like this in the past. In 1984 an extensive investigation was conducted into a fish showing similar lesions, but did not identify a cause,” he said.
Mr Appleford said previously these events had passed and stocks had recovered.
He said Port Phillip Bay acted “like a large estuary” and its waters changed to reflect many variables, including rainfall and air temperature.
“These changes can cause fish to become stressed,” he said.
“It is possible that the fish are being stressed by natural environmental variations, and normally benign ‘bugs’ are causing problems.”
