In a video that has been viewed almost 4 million times, Menindee resident Dick Arnold, right, and rancher Rob McBride say the fish kills are "a manmade disaster".
The management plan which was meant to save the Murray-Darling basin has been labelled a failure by a leading environmental professor, as the blame game over a mass fish death event in western NSW intensifies.
"What this issue highlights is how hard the management of the Menindee Lakes is".
MDBA said the incident was a "terrible reminder" of drought.
"It's a national disgrace, this once magnificent Murray cod is dead, and it absolutely stinks".
Up to a million fish are believed to have been killed in the Darling River at Menindee near Broken Hill as a result of a devastating algal bloom event.
For his part, NSW Water Minister Niall Blair visited Menindee on Wednesday to survey the carnage first hand, but snubbed the 160 concerned community members who had gathered to speak to him.More news: President Trump Is Already Anticipating the Retirement of Ruth Bader Ginsburg
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The Menindee Lakes, which are about four times the size of Sydney Harbour, were drained twice in four years and are sitting at between 2.6 per cent and 4 per cent capacity, he said. The latest fish die-off, along with other signs of wildlife and human populations hard hit by drought and heat, add to the likelihood that water will feature in this year's coming federal and NSW state elections. The dying algae worsened already low levels of dissolved oxygen in the water, pushing many fish beyond their tolerance levels.
The state's independent MP, Jeremy Buckingham, travelled to the area after the farmers' video went viral, and said he vomited when he saw the scale of the deaths.
Prof Williams admits it's hard to manage but warns there'll be more fish deaths if there isn't a 30 to 40 per cent reduction in the amount of water extracted.
Its water allocation is of "high quality" and its fish stocks are grown in "purpose built ponds with high quality aeration systems".
Michael Murray, general manager of Cotton Australia, sought to counter criticism of irrigators and his industry for the plight at Menindee, say the state's cotton output would halve this year.
"About 18 months ago, 2,000 gigalitres of water was in the Menindee Lakes before the Murray-Darling Basin Authority took the deliberate decision to accelerate releases from Menindee to meet downstream requirements and reduce overall evaporation losses from the Lakes". But, as an industry, we are growing very exhausted of being "the whipping boy" for all the problems that are being brought on by this crippling drought.