South Australian officials are monitoring a major fish kill in the Darling River in NSW amid concerns the event could spread across the border.
Millions of native fish, mostly Bony Herring, have washed up dead at Menindee and downstream towards Pooncarie, in the far west of NSW since late last month, as floodwaters receded and the region was hit by repeated heatwaves.
The mass fish kills were likely caused by low levels of dissolved oxygen in the water, known as hypoxic blackwater, which has been exacerbated by the extreme conditions.
Environment and Water Minister Susan Close said so far no such blackwater events had occurred in SA despite the recent flooding down the Murray.
The minister said environment and primary industries officials were keeping a close eye on what was happening upstream to ensure South Australia was prepared.
Water from the Darling River will start to reach SA in the coming week but will mix with water from the Murray which has higher oxygen levels.
Ms Close said that should reduce the risk of a major incident in SA.
"Whilst it is unlikely that this event will result in fish kills occurring in South Australia, they are common throughout the Murray Darling Basin," the minister said.
"We will continue to keep river communities informed of any updates to ensure they are prepared for any potential blackwater events."
Given the severity of the fish kill in NSW, police moved to reassure local residents that their drinking water was safe.
Emergency services and state government water authorities held a community meeting in Menindee on Tuesday morning to provide a possible timeline to remove and dispose of the dead fish and address concerns about water quality.
The SA government said the need for any clean-up works would be assessed on a case-by-case basis and would consider factors such as the number of dead fish, and their proximity to towns and tourist attractions.
