(CNN) Millions of dead fish have washed up in a river near a small Australian town, a phenomenon state officials say is linked to “heat wave conditions” sweeping the country.
Video surfaced this week showing masses of dead fish floating in the Menindee Weir pool near Broken Hill, CNN affiliate 9News Australia reported.
According to the Department of Primary Industries (DPI) in New South, “significant quantities” of fish, including carp and bone-in herring, along with nutrients and organic matter from the floodplain were forced back into the river due to the hot weather in Wales.
“These fish kills are related to low levels of oxygen in the water (hypoxia) as flood waters recede,” it said in a statement this week.
“This event is continuing as a heatwave…putting further pressure on a system that has been exposed to extreme conditions from widespread flooding,” the DPI said.
“The current hot weather in the region also exacerbates hypoxia, as warmer water contains less oxygen than cold water and fish have higher oxygen demands in warmer temperatures,” she added.
Heat waves across Australia have become more frequent and intense as climate change worsens and global temperatures continue to rise.
Experts and government agencies have warned Australia will continue to experience spikes in extreme rain and heat, as well as more dangerous fires.
The river in Menindee filled up with dead fish.
Menindee, a rural town in far western New South Wales, has a population of about 500 according to census figures.
Dead fish were also spotted this week in Macquarie Valley, which has both suburbs and a national park.
This was not the first time Menindee residents had witnessed a mass fish kill.
Thousands of dead fish were reported in the region in February, and a similar event happened in the region in 2019.