Emu

Hot weather could cause fish deaths

Tuesday 3 February, 2009
The current string of very hot days has resulted in extremely high water temperatures in our streams which may cause water quality issues, including the possibility of some fish deaths.

The current string of very hot days has resulted in extremely high water temperatures in our streams which may cause water quality issues, including the possibility of some fish deaths.

GB CMA Environmental Water Flow Coordinator Geoff Earl said the average water temperature in Broken Creek (at Rices Weir) has jumped from 250C to 300C, the Broken River temperature (at Benalla Weir) has gone from 230C to 300C and the Goulburn River (at Goulburn Weir) has escalated from 220C to 260C.

"High water temperatures cause severe stress in fish and other stream fauna."

Mr Earl said that introduced fish are at risk, and while our native fish are more resilient, they are still at risk.

"High water temperature reduces the oxygen available in the water adding to the stress on fish."

Mr Earl said that dissolved oxygen levels in the Broken Creek at Rices Weir have reduced from a daily range of 2 mg/l to 5 mg/l, to a daily range of 0.1 mg/l to 3 mg/l over the last week.

"The high temperatures and sometimes low dissolved oxygen levels have the potential to further impact on the environmental health of our streams, which are already stressed from low or no stream flows from the ongoing drought," said Mr Earl.

"These impacts could be catastrophic, resulting in fish deaths, or contribute to the ongoing decline of stream health."

Mr Earl said that the situation is being closely monitored and the GB CMA is working closely with Goulburn-Murray Water to manage flows in regulated streams to minimise the impacts on the environment.

"In unregulated streams, it is only a change in weather (lower temperatures and/or rainfall) that will improve the current situation," said Mr Earl.

Release Ends

For more information or a photo opportunity please contact:

Geoff Earl at GB CMA on 5820 1100
Stacey Brauman at Impress Publicity on 0400 644 637