WaterNSW is pumping oxygen into the Darling River to combat large-scale fish deaths.

The trial - a first for NSW - involves releasing highly oxygenated water from a submerged outlet to increase dissolved oxygen levels in the river, addressing one of the leading causes of large-scale fish deaths.

The project is part of the NSW Government’s action plan in response to the NSW Chief Scientist’s report into the fish deaths that occurred in the vicinity of the Menindee Lakes in March 2023.

If successful, the technique could potentially be used to increase and stabilise levels of dissolved oxygen levels at locations prone to fish deaths.

WaterNSW is conducting the trial in conjunction with the NSW Government, with NSW Minister for Water, Rose Jackson saying the strategy will hopefully offer scope to intervene more effectively when conditions increase the risk of fish deaths.

WaterNSW fish specialist, Joe Pera, said trials of the oxygenation technology in Western Australia had exceeded expectations.

“Where it was used in Western Australia the improved levels of dissolved oxygen spread beyond the immediate area of the oxygenation point,” he said.

“Obviously in bodies of water the size of Menindee lakes there is a limit to how wide the benefit would be felt, but in critical points, especially where fish concentrate or become trapped, it could be very useful in defusing the type of distressing incidents we have seen in the recent past.”

Theo Martin, from BOC, the company providing the oxygenation technology, said the firm is proud to be helping WaterNSW run the trial, which currently aims to improve dissolved oxygen levels in one section of the Darling River.

“This, and other similar BOC technology, is successfully oxygenating river systems in the Swan and Canning Rivers in Western Australia and the Murray River in South Australia to improve water quality and biodiversity,” he said.