Govt’s last-gasp scheme to save native fish
The state of many of NSW’s rivers is so dire that the Berejiklian government will start installing aerators to increase oxygen levels and keep vital stocks of native fish alive.
Primary Industries Minister Niall Blair said on Tuesday that nine of these machines will be installed ‘‘as a temporary measure’’ to help fish populations survive the brutal combination of low river flows, algal blooms and severe heatwaves.
‘‘We’re not going to die wondering – we’re trying to find a solution,’’ Blair said.
Each solar-powered aerator should be able to boost oxygen levels over an area about the size of a basketball court. ‘‘It’s not a silver bullet,’’ but it could keep some pockets of fish alive, he said. Blair was visiting the Keepit Dam in northern NSW, which is all but empty. Two of the aerators, trucked across the country from Western Australia, will be installed in remaining pools at that reservoir.
Four others will be installed on the Darling River, including near Menindee, site of the last week’s massive die-off that killed as many as a million fish. These included endangered silver perch, as well as golden perch and giant Murray cod, some of which were decades old. The other three machines will go to Burrendong Dam on the Macquarie River, where the Macquarie perch are also at risk, Blair said.
Minister Blair said his department would look at adding enclosures to prevent poaching by anglers drawn to the remaining healthy fish stocks.
Blair repeated his concern that yesterday’s meeting of water officials in Canberra would fail to produce any clear outcomes.
Ministers weren’t invited to the event, to be held at the Murray Darling Basin Authority from 2pm, and even federal Water Minister David Littleproud – who is in Berlin, Germany – won’t attend. ‘‘It was all news to us,’’ Blair said. ‘‘I’m at a bit of a loss – what is it going to do?’’
Areas of immediate worry for more fish kills include the Murrumbidgee River and even the Murray River, although the extent of the problems mean ‘‘we’re concerned pretty much everywhere’’, he said. The Menindee fish kill was triggered by a sudden drop of temperatures after a severe heatwave nudged the mercury to 46 degrees. Dying blue-green algae resulted in further drops of already low dissolved oxygen levels, pushing many thousands of fish beyond their tolerance levels.
Richard Kingsford, director of Centre for Ecosystem Science at University of NSW, said that aerators are routinely used on dams supplying water to communities. ‘‘It’s a band aid,’’ Kingsford said. ‘‘They’ll do a little bit for a little while. It still leaves a lot of river that’s been affected."