Vegetation blamed for fish deaths
Thursday, 9th June, 2011
The large amount of rotting vegetation and other organic matter being washed down the Darling River is now believed to have been the cause of the deaths of thousands of fish at Menindee.
The NSW Office of Water and the State Water Corporation said yesterday that they would "immediately" double the flows from the Lake Wetherell outlet to flush out the river.
The flows will be increased from 500 megalitres a day to 1,000 megalitres.
It will raise the gauge height at Weir 32 by about seven centimetres, the authorities said.
The action was being taken to improve the water quality by raising the levels of dissolved oxygen in the Menindee town weir pool, they said.
Late last week the BDT received reports from Menindee that thousands of fish were dead and dying.
A State Water spokesman was quoted in the BDT on Monday as saying that the carnage might have been caused by a sudden drop in the water temperature and that is was nothing to worry about, especially since most of the dead fish were the pestilent carp.
Breeding conditions at the moment were also ideal, he said, and with the fish stocks being so high it might have been a case of young fish "succuming to the elements".
But yesterday the NSW Office of Water said that the majority of the fish killed were small Bony Brim and that there had been reports of Perch and Murray Cod suffering as well.
"It is believed that with the lack of water movement recently in the weir pool, and despite cooler temperatures, high organic loads from recent flooding have depleted the water of oxygen," said a spokesman for the Office.
Staff from the NSW Office of Water and the State Water Corporation were "continuing to monitor and manage the situation."
On Tuesday the BDT received a phone call from a man who said he was sitting by the river and could see a mass of fish, either dead or dying, and stretching from bank to bank.
"If I was three stone lighter I could walk across it," said thee elderly gent, who did not want his name published.