Loading 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. Mr 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 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, Mr Blair said.

Minister Blair said his department would look at adding enclosures to prevent poaching by anglers drawn to the remaining healthy fish stocks. An example of solar-powered aerator that the NSW government is planning to deploy. Credit:Solair Group Hume Dam The Hume dam has also had a fishkill, Mr Blair said on Tuesday, with 60 carp so far identified as perishing near the Bowna Arm boat ramp. Initial reports had estimated as many as 1800 fish had died, the Department of Primary Industries said in a statement. The department said the cause had not been identified, "however there are no algal or dissolved oxygen issues noticeable. Fishing mortality is one potential cause".

Paul Humphries, a fish and river ecologist with Charles Sturt University in nearby Albury, said algal blooms in the Murray are "usually sourced from Lake Hume". Given the period of very high temperatures in the region, an algal bloom in the Hume storage "is certainly a major concern," Dr Humphries said. WaterNSW earlier posted on social media an extended "red alert" for blue-green algae in the lower Murray River. "With drought conditions expected to continue over the coming months it is likely more fish kills will occur without significant rainfall to generate replenishment flows," DPI said.

Loading 'All news to us' Mr Blair, meanwhile, repeated his concern that Tuesday'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," Mr 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. Much of inland Australia is forecast to exceed 45 degrees on Tuesday. For places such as Hay on the Murrumbidgee, the coming four days are predicted to hit 47, 47, 46 and 46 before cooling off to a maximum of 31 degrees by Saturday, according to the Bureau of Meteorology. Menindee is also expecting similarly hot temperatures during this period. Loading Replay Replay video Play video Play video

'Band aid' 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," Professor Kingsford said. "They'll do a little bit for a little while. It still leaves a lot of river that's been affected." Tim Beshara, federal policy director for the Wilderness Society, said that all governments needed to be looking at everything possible to help creatures survive the next few weeks and give the ecosystems to best chance to recover when it does rain. "That might mean aerators, it might mean capturing populations of endangered fish and bringing them temporarily into captivity," he said. "This is the scary new world we now live in where we humans must play god to keep nature going."