Dead fish scattered through Lower Darling, but Murray ok for now, say authorities

Horrifying pictures of thousands of dead fish in the Lower Darling have emerged, raising concerns about the effect of the upstream drought on the Murray in South Australia.

Horrifying pictures of mass fish deaths in the Lower Darling have emerged, raising concerns about the effect of the upstream drought on the Murray in South Australia.

Water authorities say the mass fish deaths from blue-green algae are specific to NSW, which has been hit hard by the drought, and will not affect SA.

Before Christmas about 10,000 native fish died.

They are mostly Murray cod and perch species. In hot weather the algae saps the oxygen from the water in stagnant sections of the river. The blooms can also release toxins.

Centre Alliance Senator Rex Patrick was sent pictures and a startling video of the dead fish and said fish spawned in the Darling system comprise a proportion of South Australian populations.

Video from Menindee resident this morning with more fish having died overnight. Numbers could move into six figures 3/3 pic.twitter.com/sjcXw5IRQx

— Rex Patrick (@Senator_Patrick) January 6, 2019

“There must be no water flowing from the Darling River into the Murray,” he said.

“The Darling River, a river that is crucial for river flow through the Murray Mouth and into the Coorong, is dying and the Government is simply not acting.”

But the Department for Environment and Water says the algae and deaths will not impact SA because they are a localised reaction to hot weather, low flows and algal outbreaks.

“Presently in SA we are experiencing reasonable flows in the River Murray, and also the delivery of environmental water,” River Murray operations manager Jarrod Eaton said.

“There is always a risk of algal outbreaks along the River Murray during summer and autumn when temperatures are higher and flows may be lower,” he said.

“It is important to note that not all algae are toxic species and that algae is always present in the River Murray.”

Disturbing images of dead Murray Cod along the Darling River near Menindee. Tweet from Senator Rex Patrick @Senator_Patrick/Twitter.

The Murray-Darling Basin Authority said the Lower Darling had been under prolonged stress from the drought, which left fish populations vulnerable.

“Due to the ongoing drought, levels at Menindee Lakes are currently very low, at 5 per cent, and there is no water entering the lakes from the Darling River upstream,” a spokesman said.

“NSW is managing what little water there is in the lakes.”

The Coorong has already been found to be in a vulnerable state despite the delivery of water under the Murray-Darling Basin Plan. However, the State Government has said it is starting to recover.