Politicians are calling for the urgent removal of 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.
The NSW Department of Planning and Environment saidon Saturday it would continue to monitor the situation closely and keep the community informed.
The department said the die-off of the fish, mostly bony herring, had been caused by floods and hot weather leading to extremely low dissolved oxygen levels being recorded in the river.
The statement added that this weekend’s extreme temperatures had worsened the problem and was likely to lead to further fish die-offs in coming days.
Locals say the smell is terrible, with videos on social media showing a thick layer of fish floating on the water, which has turned a shade of bright green in places.
The federal opposition spokesperson 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.
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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.”
The NSW Green’s spokesperson on water Cate Faehrmann said the fish needed to be removed as soon as was feasible, before they 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.
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“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 water quality degrading further.
The Bureau of Meteorology has predicted temperatures in the far west of NSW to reach up to 40C this weekend, with much of Australia’s east coast baking in unseasonal autumn heat.
A 40km-long algal bloom in the same part of the river was blamed for the death of 1 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.
