Hazelwood barra population thinned to ensure survival
THE Victorian Fishing Authority has culled some of the smaller and weaker barramundi in Hazelwood Pondage in an effort to make sure there is enough food remaining for the healthy majority.
According to a report on the ABC website, between 400 and 500 fish were culled, after a drop in water temperature killed off some of their food sources. This report discredits an earlier report from the Northern Territory that several thousand of the Hazelwood barra had perished.
The Victorian Government introduced 7,000 of the warm-water game fish into the pondage last year for recreational fishing, just months before Hazelwood's owner Engie announced the plant would close.
Concern for the fish had been growing after warm water from the power station was turned off, and the water temperature dropped from 22 degrees Celsius to below 15 degrees.
As the water temperature dropped the majority of the fish found their way into a warm-water channel, fed by hot artesian water pumped from the base of the mine.
In May, Fisheries officers stunned and moved about 100 of the game fish into the warmer section.
But the cold water temperature killed some of the barramundi's key food sources, and investigations by the Victorian Fisheries Authority showed some of the weaker fish were not eating.
Authority chief executive Travis Dowling said some barramundi showing signs of ill health had been removed.
The fish were culled by electrofishing, which involved sending an electric current through the water to shock the fish.
The sick, underfed or small fish were then pulled out, leaving the healthy fish to recover.
"The Victorian Fisheries Authority is working to remove any barramundi in the pondage that are showing signs of ill health," he said.
"We've taken out probably up to half a tonne of barramundi and we estimate that there is approximately two tonne of barramundi remaining in the pondage."
Mr Dowling said the fish would have been unlikely to survive the winter.
"They would have died under the cold conditions so we're making sure that those fish are being removed and basically we're disposing of those fish," he said.
"We've done that because we want to make sure there's food available for the remaining fish in there.
"We're taking steps, as we do with other fisheries, to make sure we have a really good barramundi fishery for the valley going forward."