Millions of dead fish choke Australian Outback river

Millions of dead and rotting fish have clogged a vast stretch of the river near a remote town in the Australian Outback as a searing heat wave sweeps through the region.

Videos posted on social media showed boats ploughing through a blanket of dead fish smothering the water, with the surface barely visible beneath.

The New South Wales government said on March 17 that millions of fish had died in the Darling River near the small town of Menindee, in the third mass kill to date in the area since 2018.

There is dead fish, as far as you can see, said Menindee local Graeme McCrabb.

He said it was surreal to comprehend that this year's fish kill appeared to be worse than previous ones.

According to the state government, populations of fish such as bony herring and carp had surged in the river after recent floods, but were dying off in huge numbers as floodwaters receded.

The government said these fish deaths are related to low oxygen levels in the water hypoxia as flood waters recede.

The current hot weather in the region is also exacerbating hypoxia, as warmer water holds less oxygen than cold water, and fish have higher oxygen needs at warmer temperatures. Previous fish kills in Menindee -- about 12 hours drive west of Sydney - have been blamed for a lack of water in the river due to prolonged drought and a toxic algal bloom that stretched more than 40 km.

The New South Wales government warned in 2019 that this won't be the last.

Cameron Lay, a state government fisheries spokesman, said it was confronting to see the river choked by dead fish.

He told ABC that we are seeing tens of kilometres where there is fish really as far as the eye can see.

Menindee has a population of around 500 people and has been ravaged by drought and flooding in recent years.