Forcing oxygen into sick rivers, adding water to “fish refuges” and potentially even relocating critical species are the main options being considered by stakeholders to try and prevent further fish deaths in Australia’s biggest river system.
Aerators are to be placed in the Darling River as part of a suite of new strategies to try and prevent future mass death events in the Murray-Darling basin.
Four of the solar-charged machines will be installed in the Lower Darling region after an estimated one million fish died at Menindee last week.
“They are a bandaid solution – we admit that – (but) nothing will stop this fish kill unless we get proper river flows and levels in our dams back to normal,” NSW Primary Industries Minister Niall Blair said on Tuesday.
“We are looking at doing everything we can to try and limit the damage.”
The minister has said the Menindee event was a “perfect storm” caused by severely low water flow, algal blooms and a sudden drop in temperature.
NSW will also install aerators sourced from Western Australia at Lake Keepit near Tamworth and Lake Burrendong near Dubbo.
The machines and increasing water flows were among the potential solutions discussed at an urgent meeting of Murray-Darling basin officials in Canberra on Tuesday.
Murray-Darling Basin Authority chief executive Phillip Glyde said in some circumstances adding water may help protect key refuges for native fish.
“This includes the use of available environmental water allocations and the use of consumptive water on route,” he said in a statement.
River managers, environmental water holders and fisheries scientists also discussed relocating critical species of fish to healthier habitats and an “exploring new technologies”.
But Mr Glyde conceded the relocation option was challenging due to biosecurity issues and fish stress.
People living along the Darling River were urged to remember 20 per cent extra water will come down the river in future years under the basin plan.
“It’s a hard ask to get people to just accept that help is on its way, because it is so slow in coming, but it is on its way, and I urge everybody to stay the course,” the chief executive told ABC TV on Tuesday.
Senior government officials will return to Canberra on January 22 for a follow-up meeting.
Federal Water Minister David Littleproud wants $5 million of Murray-Darling basin funds for a strategy to look after native fish.
Labor leader Bill Shorten wants an emergency task force to investigate the ecological disaster and has called for a more bipartisanship approach.
The NSW government on Tuesday was forced to drastically revise down the number of fish thought to have died in another event near the NSW-Victorian border.
After initially suggesting some 1800 fish had died in Lake Hume, the government said an investigation had found approximately 60 dead carp in the Murray River lake.
“Fishing mortality is one potential cause,” the primary industries department said.