CANBERRA, Australia -- Hundreds of thousands of fish died on Monday in the third mass death in recent weeks on a stretch of a major Australian river that local officials blamed on drought but critics said at least partly stemmed from water mismanagement.
The latest deaths began overnight in the Darling River near the township of Menindee in western New South Wales state. That's the same area where hundreds of thousands of fish were found floating dead in early January and shortly before Christmas.
Hot weather is suspected of causing algae to bloom, then cooler overnight temperatures caused the algae to die, which starved the water of oxygen.
New South Wales Premier Gladys Berejiklian blamed the poor water quality on an extended drought that is gripping most of the state.
Minister for Regional Water Niall Blair said his department knew weather conditions were "terrible" and had deployed two solar-powered aerators in the Menindee region. The government bought 16 aerators to deploy in waterways around the state after the last mass fish death on Jan. 6-7.
"Unfortunately, there's nothing that anyone has been able to point to — no scientist, no locals, no one has been able to point to anything else that could prevent something like this other than freshwater coming into the system and we just don't have that," Blair told reporters.
Menindee Regional Tourist Association president Rob Gregory, who operates river cruises, said governments had allowed farmers to take too much water from the river to irrigate over the last four years.
"Now we've got no reserve to flush the system and we've seen depleted oxygen due to blue-green algal bloom and this is the end result," Gregory said.
"This is probably the last fish kill we'll have because there's nothing left to kill," he added.
The Murray-Darling Basin is Australia's main river system. It winds across four states and produces a third of the nation's food.
Menindee resident Graeme McCrabb said the fish deaths highlighted how the water basin's water management plan "is failing the whole system."
"There's been 13 billion (Australian) dollars ($9.3 billion) of taxpayers' money being spent here to end up with ... an absolute mess," McCrabb told Australian Broadcasting Corp.
With a federal election to be called before the end of May, opposition environment spokesman Tony Burke called for a scientific explanation for the latest fish deaths.
"The last river I was at was the Darling, where you can just see the ecological disaster that's occurring," Burke told reporters.