Fish deaths in Menindee

Responding to mass fish deaths at Menindee

NSW Government agencies, along with the Australian Government and local partners have been undertaking water quality monitoring since early Spring 2022 to review dissolved oxygen conditions across NSW, identify potential risks to ecological communities, implement mitigating measures to evolving blackwater occurrences and respond to the mass fish death event in the Darling-Baaka River that occurred in March 2023.

The immediate causes of the fish deaths are believed to be attributed to hypoxia, caused by a combination of hypoxic blackwater, a high biovolume of algae, and a significant biomass of fish, as a result breeding following three wet years. Hypoxic blackwater is a naturally occurring phenomenon which causes extremely low dissolved oxygen levels. The Office of the Chief Scientist and Engineer also found that mass fish deaths are symptomatic of degradation of the broader river ecosystem over many years.

Taking action to address the Office of the Chief Scientist and Engineer report

The NSW Government has released its first formal response PDF, 5698.64 KB to the Office of the Chief Scientist and Engineer report into mass fish deaths on the Darling-Baaka River near Menindee in March 2023. In the first half of 2024 we will release our phase 2 response to the report.

We are taking immediate action to address the findings and recommendations  with all levels of government and partner agencies are working closely together to rollout critical work that will improve water quality and native fish health across the Murray-Darling Basin. Actions being taken in the next 12 months include:

• Continuing to adjust water releases from Lake Pamamaroo to keep an oxygenated flow through the Weir 32 weir pool to support native fish.
• Establishing an independent expert panel on Barwon-Darling River connectivity which will deliver its first draft report by early 2024 on improving flows before, during and after drought.
• Boosting water quality monitoring.
• Carrying out temporary fish passage investigations and progressing planning for permanent fish passages with a $2 million contribution from the Australian Government.
• Trialling cutting edge technology to put oxygen into the water, similar to what is occurring in Western Australia.
• Creating a role to employ staff based in the Far West to better connect with the community on water quality and water management issues and incorporate local knowledge.

Read the detail of our response PDF, 5698.64 KB