Australian authorities hired contractors to remove millions of rotting fish from the Darling River, police said on Monday.
The fish started dying in the river near the New South Wales town of Menindee on Friday.
Environmental authorities believe the drop in oxygen levels in the water after the recent floods receded likely caused the incident. This is because fish need more oxygen in hot weather, and climate change has let to unseasonably warm temperatures of up to 40 C (104 F).
Local water supply threatened
Police Assistant Commissioner Brett Greentree said the main concern currently was keeping the town's water supply clean.
"I understand and acknowledge the smell and sights on the river — nobody wants to see that," he added.
Authorities were supplying potable water to residents who rely on river water, which was continually being monitored for quality, Greentree said.
Addressing the scope of the removal process, another pressing issue, Greentree said that he cannot promise that "all the millions of fish" will be removed because it is a "logistical nightmare."
Meanwhile, locals expressed displeasure at perceived lack of urgency towards the clean-up.
"Other than rainwater ...we 100 percent rely on that river for our household domestic use," Karen Page, a Menindee resident, told state broadcaster ABC. "As soon as they've seen what was happening, they should've had that equipment here. They should've already been cleaning this out."
Mass fish deaths reoccurring
There have been more reports of mass fish deaths on the Darling River recently.
Tens of thousands of fish were discovered at the same location in late February, and there have been several reports of dead fish downstream into Pooncarie, near the borders of South Australia and Victoria.
The latest incident comes after up to a million fish perished in the same location in 2018 and 2019 due to inadequate water flow, poor water quality, and rapid temperature fluctuations.
Greentree said that the current death toll appears to be significantly higher than in 2018 and 2019.
