Darling River aerators 'not working properly'

Fish kills: Solar-powered aerators placed in shade on Darling

Graeme McCrabb checks dissolved oxygen levels in the Darling River nearly daily.

Graeme McCrabb checks dissolved oxygen levels in the Darling River nearly daily.


Locals advocate for diesel-powered river aerators to stop fish kills, say solar units not working well.


A series of mass fish deaths in far west NSW have left locals on edge with some regularly checking the Darling River's water quality for signs of another mass kill.

Algal blooms, rapid temperature changes and low water flows have all contributed to three mass fish deaths at Menindee this summer with the NSW government installing aerators in an attempt to reduce further deaths after the second event.

Four of the solar-charged machines were installed in the Lower Darling region to boost oxygen levels but Menindee resident Graeme McCrabb claims they aren't working as well as they should.

"They're solar powered and have been placed under trees where they can't get enough charge throughout the day to work in the evening when they're needed," he told said in Menindee.

Mr McCrabb, who moved to the area a few years ago because of his love of fishing and the Darling River, checks the dissolved oxygen levels in the river nearly daily.

Dissolved oxygen is a key indicator of water quality and is essential for the survival of fish and other aquatic animals.

Levels between four and seven milligrams per litre mean the water quality is good but near Weir 32 on the river, the levels are falling below two which is deadly for fish, Mr McCrabb says.

"Everyday I check where there could be another kill," he said.

"The fish are just super stressed. Thirty-odd cod died lately, and there's fish dying 150kms down the river. They all start to add up."

A diesel-run aerator which was donated to the area by not-for-profit group OzFish Unlimited has boosted dissolved oxygen levels but only within some 100 metres of the machine.

Poor quality water further upstream where the fish deaths occurred is also trickling down to lower pools of the river and is decreasing the water quality downstream, Mr McCrabb said.

"There's absolutely a good chance there will be more deaths downstream," he said.

NSW Regional Water Minister Niall Blair said he was happy to consider different types of aerators to help stressed fish in the river.

"We never said it would be a number one fix," he said on Thursday.

"We're happy to take onboard the feedback and look at different types."

Australian Associated Press


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