Politicians are calling for the urgent removal of the millions of dead fish that are clogging the waterways of the lower Darling-Baaka River near Menindee, in the far west of New South Wales (NSW).
The NSW Department of Planning and Environment said in a statement on Saturday it will continue to monitor the situation closely and keep the community informed.
The Department said the die-off of the fish, mostly bony herring, was caused by recent floods and hot weather leading to extremely low dissolved oxygen levels being recorded in the river earlier this week.
The statement added this weekend’s extreme temperatures worsened the deaths, and will likely lead to further fish die-offs in coming days.
Locals say the smell of the rotting fish is terrible, with video on social media showing a thick layer of fish floating on the water, which has turned a shade of bright green in some sections of the river.
The federal opposition spokeswoman for Water, Perin Davey, said the national and NSW governments should be looking at ways to dispose of the rotting fish as soon as possible.
Senator Davey suggested adapting aspects from the National Carp Control Program, which was created after six years of research into Carp biocontrol strategies.
“We know one of the biggest concerns for carp biocontrol was what to do with the dead fish,” Davey said.
“The current natural event that we are seeing, with hundreds of thousands of dead fish floating along the Darling, provides an opportunity to test the clean-up options that scientists have considered under the carp control program.
“The current event is too urgent to go back to the drawing board, we need urgent action,” she said.
The NSW Green’s water spokeswoman Cate Faehrmann said the fish need to be removed as soon as is feasible, before they decompose and cause an ecological disaster.
“This is categorically a catastrophe, regardless of whether this is a consequence of receding floods or water mismanagement, the NSW and federal governments should be acting now to clean up the millions of rotting fish which are spanning kilometres of the river,” she said.
“Right now, every natural aspect of the river and the communities that rely on it for water are threatened with cascading collapse and these millions of fish that are rotting away are a harmful tragedy and will further degrade the system and quality of the water.”
Faehrmann said the NSW and federal governments should be acting together to clean up the fish to prevent the water quality degrading further.
The Bureau of Meteorology has predicted temperatures in the far west of NSW to reach up to 40 degrees C this weekend, with much of the east coast of Australia baking in unseasonal autumn heat.
A 40 kilogram algal bloom in the same part of the river was blamed for the death of one million fish in 2019.
The 2019 event coincided with a period of high temperatures in the state’s far south, and drought along the river system.
This week’s fish die-off is expected to exceed the 2019 event.
