The NSW Government said they would fast track the installation of up to four water aerators at Lake Burrendong to assist with oxygen levels.

However, Mr Hansen is concerned all the political arguing over recent fish kills will impede any real action to stop it happening again.

“The scary thing is that if this drought is only just warming up, fish kills like we’ve seen at Menindee and now at Lake Burrendong could look small,” he said.

“There is no doubt that we would’ve had fish kills like this happen across the Murray Darling basin in years gone by, but the difference between then and now is our native fish stocks have crashed by 70 to 90 per cent in parts of the basin, we’re talking about playing with the last remnants of broodstock.

“What would’ve happened in the past was stronghold areas would then come back and re-populate the areas where we had a fish kill. But because we now have so many barriers to fish passage, so many dams, so many weirs, so many culverts that fish can’t get past right across the Murray Darling basin, the chance of areas that have had fish kills to recover is minimal because fish simply can’t move around the basin like they once did.

“We have now seen the biggest kick in the guts for native fish, and the chance of recovery is minimalised because there’s just not the stocks there to re-populate.” 

Minister for Regional Water Niall Blair said the State government believes the primary driver for the kills was a sudden reduction in oxygen levels when organic debris started to decompose.

“While water aeration won’t stop potential kills, it does provide localised areas, about the size of a basketball court, a place where fish can get more oxygen,” he said.

Healthy River Ambassador Mel Gray said she believes the NSW government prioritises irrigation over the environment.

“I completely support Mr Hansen’s call for removing of barriers to fish passage and screens on pumps to stop fish getting extracted,” she said.  “Water aerators are a necessary short term solution, but I think our rivers are over-allocated, water is life in the basin, the basin plan as it stands is not the best for the rivers and wetlands, it is flawed.

“We need to improve it, far too much is done for irrigators and the environment is not a priority.  You can see it when you look at some of the water sharing plans, our systems are intolerably stressed, our marshes are shrinking and our groundwater sources are receding, and our surface water supplies are ever decreasing.”