Millions of fish have died in the Darling River in western New South Wales, triggering a major clean-up effort. Police and volunteers from the conservation charity OzFish have started clearing fish from high-density areas, but they admit that not all carcasses will be removed. The emergency hub in Menindee is coordinating the response and monitoring water quality. The fish deaths are believed to have been caused by a lack of oxygen in the river after a recent heatwave. Contractors will use a netting procedure to remove the fish, but local residents have been warned that not all of the fish can be cleared.

OzFish volunteers have also started a search and rescue operation to save surviving native fish from the river. The majority of the dead fish are native species, including Bony Bream and Golden Perch, with the remaining being non-native species such as carp. Hypoxic blackwater is thought to be the cause of the deaths. State government agencies are working with federal agencies to investigate the underlying cause. The Murray-Darling Basin, which is Australia’s largest river system, is facing increasing pressure due to drought and human activities. NSW Police Commander Brett Greentree described the event as unprecedented in terms of the millions of fish that have died. He assured residents that the water supply remained high-quality and that the contractors with specialized skills would remove as many fish as possible. OzFish’s director of programs, Cassie Price, warned that the remains of the fish would likely sink to the riverbed, causing a nutrient spike and algal blooms. She also explained that this would cause more issues in the future.