High heat and floods newly kill millions of fish

Today, numerous video clips have revealed that millions of decaying fish are being removed from a stream in the Australian Outback due to an unexpected mass death caused by flooding and scorching hot temperatures. [i]

The fish mortality began in the Darling River water source near Menindee, New South Wales, on Friday and continues to spread to other areas along the river. [i]

Local authorities have been working around the clock to collect the dead fish, believed to have been killed by the sudden influx of water and the rapid rise in temperatures. [i]

This is the second mass fish death in the Darling River this year, and conservationists are worried that more deaths could happen if the conditions are not improved. [i]

With the help of local volunteers and environmental agencies, authorities are doing everything possible to prevent further damage to the river’s ecosystem. [i]

The authorities suspect that the scorching temperatures and low oxygen levels in the water caused the mass mortality of fish. The recent floods worsened this situation, further reducing the amount of oxygen available to the fish. [i]

The heat waves caused the water to become warmer and less able to hold oxygen. At the same time, the flood, further reducing that further reduced the amount of oxygen by blocking the sunlight needed to produce it. [i]

The high water temperature and the lack of oxygen caused a drastic shift in the lake’s environment. This shift was so severe that the fish could not survive and quickly died off in large numbers. [i]

The high water temperature and lack of oxygen caused the lake to become uninhabitable for the fish. As a result, fish die due in part to low oxygen saturation levels that require medical attention or supplemental oxygen. [i]

Watch a short clip of the dying fish below

Read the full Investigation Report from a similar 2018/2019 fish death event in the lower darling river here or below.

Police have opened up an emergency center in Menindee to help manage the cleanup process. Assistant Commissioner Brett Greentree mentioned that keeping the town’s water safe was a high priority, with removing the dead fish being the next most important task. [ii]

Trained professionals have been contacted about taking away the fish, but a specific date for the job has yet to be determined. Mr. Greentree noted that it would be difficult to remove all the fish due to logistical issues. [ii]

He was aware of the smell and sight of the river and wanted to help restore it. Authorities supply potable water to people who rely on the river and regularly monitor the water quality. [ii]

Recent weeks have seen multiple accounts of large-scale fish fatalities on the Darling River. [iii]

A large and shocking number of fish were discovered dead near Pooncarie, a small town near the border between South Australia and Victoria. [vi]

This happened during the extreme drought that struck the area in 2018 and 2019, with the most devastating fish kill occurring in the Menindee stretch of the river. Reports estimate that millions of fish perished during this period, with several species particularly affected. [vi]

The cause of the fish kills was blamed on a combination of factors, including low water levels in the rivers, high temperatures, and increased salinity levels due to the over-extraction of water for irrigation. The devastating event led to a call for better environmental management and stricter regulations for water usage. [iii]

Mr. Greentree noted that the death toll is much higher than in the past two years. Peter Thurtell, the State Emergency Operations Controller, then declared that the immediate goal was to provide clean water to the residents. [iv]

He further explained that there were multiple viable solutions to maintain the water supply in the Menindee area. A local nature photographer, Geoff Looney said it was an overwhelming stench, making him worry about his health. He also reported that numerous fish were floating down the river. [iv]

Jan Dening, a Menindee local, commented on the aftermath of the recent environmental disaster, saying that the area was filled with a putrid smell and the sight of all the dead fish was terrible. She said they had just started the cleanup process when the tragedy occurred. [v]

References

[i] Marina Alikantes, In one of the rivers of Australia, found about a million dead fish (Mar. 18, 2023)

[ii] Paulina Vidal and Bill Ormonde, ‘Significant planning’ underway to clean up massive fish kill in NSW’s far west (Mar 19, 2023)

[iii] Department of Primary Industries, Fish Death Investigation Report Lower Darling River Fish Death Event, Menindee 2018/19 (2019)

[iv] Kalkine Media, Emergency operation to deal with millions of dead fish (Mar. 19, 2023)

[v] Bill Ormonde, Greta Stonehouse Millions of fish dead in the worst mass kill ever to hit Menindee region, in NSW’s far west (Mar. 17, 2023)

[vi] Department of Primary Industries, Fish Death Investigation Report Lower Darling River Fish Death Event, Menindee 2018/19 (2019)