Cockburn Sound fish deaths cause could remain unknown for 10 days

THE Department of Fisheries is continuing to co-ordinate laboratory investigations on samples of dead fish collected from Cockburn Sound, but until the results are available from the fish pathology and chemical analysis of water samples, the cause and potential impact could remain unknown for up to 10 days.

More than 700 dead fish have washed up at various locations in Cockburn Sound, and more samples have been obtained to support Fisheries Officers’ ongoing investigations.

All new samples are being checked by the department’s Fish Health branch, but results of the comprehensive tests may take between five and 10 days to assess.

Biosecurity research scientist Dr Michael Snow said a pollution event could not be ruled out, however preliminary laboratory findings suggested no evidence of algal blooms or disease being a contributing factor.

“This fish kill event has affected multiple species of fish and, while disease also can’t be ruled out at this stage, the fact that multiple species have been involved suggests disease is less likely,” Dr Snow said.

The Department of Health has advised people not to swim in areas of water with large numbers of dead and decomposing fish because they may contain high levels of bacteria and bad odours, and not to fish in water with large numbers of dead fish.

They have also advised people to temporarily not to collect or consume fish from Cockburn Sound and not to collect and use dead fish for bait or consumption because of the risk of high levels of bacteria.

Due to fishing closures, fishers should not be fishing for crabs in Cockburn Sound, and both Cockburn and Warnbro Sounds have spawning closures on pink snapper fishing in place.

Pink snapper are currently spawning in Cockburn Sound and until results from the fish pathology group and the chemical analysis of the water samples are available, the potential impact on spawning would be unknown.