DOZENS of Murray cod, some possibly more than 80 years old, have died at Menindee in NSW’s Far West after sudden temperature changes disrupted algal blooms and reduced oxygen levels in a 40-kilometre stretch of the Darling River.
They are among an estimated million fish, which also included silver and golden perch and bony herring, that have died in the region because of two similar incidents, one in mid-December and one at the weekend.
The region is a major breeding ground for some of the country’s native fish and SA is being warned these events and ongoing dry conditions could have major ramifications for water users downstream.
Menindee local and keen fisherman Graeme McCrabb said they found more than 120 dead cod along the affected stretch of the river.
“One was 1.27 metres – 80 to 100 years old,” he said.
“That cod has been through many droughts and floods in its lifetime, and it’s dead on the back of $13.5 billion spent on improving environmental outcomes as part of the Murray-Darling Basin Plan – it defies logic.”
He stressed these were not just local fish, but stocks for the entire basin.
“About 80pc of the golden perch in the basin is bred at the Menindee Lakes,” he said. “If you want to catch a golden perch at Loxton, there is a high chance it came from Menindee.
“Menindee and the Lower Darling are also a key part of the cod breeding process and those breeders are gone.
“This fish kill has done massive damage to the fish ecology of the whole basin.
“We need people to see how important this area is and how important the lakes system along the Darling River is to the rest of the system.”
NSW Regional Water Minister Niall Blair has blamed the ongoing drought in NSW for the fish deaths.
“Without significant rain to generate replenishment flows, these impacts will persist and possibly increase as summer proceeds,” he said.
Mr Blair visited Menindee yesterday (Wednesday) to see the impacts first-hand, and was confronted by many angry locals.
Many Menindee residents refute the water problems are solely because of drought.
Mr McCrabb said the bigger issue was the mismanagement of the Menindee Lakes by the NSW government and MDB Authority.
The Menindee Lakes, fed by the Darling River, are the town water supply for Broken Hill, NSW, and surrounding towns, such as Menindee.
On Tuesday, WaterNSW figures showed that only 205 megalitres a day was flowing past Weir 32 at Menindee, while the Menindee Lakes were only 3.4 per cent full.
“The lakes were more than 80pc full less than two years ago,” Mr McCrabb said.
"The bulk of that water was released downstream to SA in less than 12 months, leaving us with no reserve to protect our local habitats.
“Mr Blair is blaming ‘the worst drought in 100 years’ for the lack of inflows, which is true, but if they had managed the lakes better, we wouldn’t be in this situation.”
Menindee Tourism Association president Rob Gregory said the thousands of dead, rotting fish had since sunk to the bottom of the Menindee Weir pool.
“It’s the height of summer and people can't run their air-conditioners because the water is foul,” he said.
Tolarno Station owner Rob McBride, Menindee, was concerned the toxins from the algal blooms and dead fish would end up in the Australian food supply.
“Our livestock drink this water so we are putting toxins into our food supply,” he said. “We are putting lives at risk and it has nothing to do with drought.
“It has everything to do with the actions of the MDBA and the NSW government to drain the Menindee Lakes twice in four years.
“Tens of millions of fish will die along the Darling River in the next few months because algal bloom events are expected to increase.
“That’s why the lakes are so important, to dilute and flush these algal blooms down the river system but we can’t because they are dry.”
Mr McBride said the country was facing an “ecological disaster”.
“Once the Darling dies, over-extraction on the River Murray will take place, salinity will increase, the availability of water will decrease and water prices will be pushed up,” he said.
“SA needs to understand that the River Murray is going to pay the full price of the destruction of the Darling River system.”
But SA Department for Environment and Water River Murray operations manager Jarrod Eaton said the situation posed no risk to SA as there was presently no flow from the Lower Darling River into the River Murray.
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