Communities within the Barwon-Darling, Murray, Lachlan and other inland catchments are being warned to be on alert for fish deaths in the coming days, poor water quality has driven hundreds of crayfish away from the Murray river. 

The NSW Department of Primary Industries (DPI) is conducting a rescue and relocation operation to save Murray Crayfish impacted by poor water quality along the Murray river. 

DPI Deputy Director General Sean Sloan said Fisheries has received reports of hundreds of Murray Crayfish leaving the water in the south of the state and northern Victoria. 

The species is nationally listed as a threatened species. 



“Extensive rainfall across most of the Murray-Darling Basin has resulted in increased inundation of floodplain areas, causing poor water quality, including low dissolved oxygen levels through decaying grasses, leaves, crops and other organic matter being washed into the river systems,” Mr Sloan said. 

“When dissolved oxygen drops to very low levels, this can cause ‘hypoxic blackwater’ which can be stressful for native species including Murray Crayfish, so they leave the water in high numbers,” he said. 

The Murray-Darling Basin Authority has monitored rivers across the basin, reporting that the Lower Macquarie, Castlereagh, Bogan, Lower Lachlan and Barwon-Darling are likely suffering from low dissolved oxygen, with algal blooms possible in the Lower Lachlan. 

The rescued crayfish will be transported to Narrandera Fisheries Centre for safekeeping until conditions improve and they can be returned to the river.

“We want to remind fishes that while Murray Crayfish may leave the water for a period of time during flooding and blackwater events, all NSW laws relating to taking of Murray Crayfish continue to apply,” Mr Sloan said. 

“Fisheries Officers are actively patrolling the area to deter any illegal activity, so please do not interfere with crayfish or try to collect them, as some may return to the water when water quality improves,” he said. 

While the flooding should be beneficial for native fish communities in the coming years, they must negotiate poor water quality over the coming weeks. 

Fishers and community members are encouraged to report any fish deaths or observations through the Fishers Watch phoneline on 1800 043 536.