WATCH: Hundreds of thousands of fish die in Australia
Authorities are blaming the mass death on a toxic algae bloom due to changing weather conditions.
It's the second incident of mass fish death along the Darling River since 10 000 fish died in December.
Officials said that a sudden cooling of the temperature over the weekend killed a pre-existing algae bloom in the area.
It resulted in the decomposing algae draining oxygen from the river.
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