THE most impressive Murray cod breeding in 20 years is under way in the Lower Darling River as a result of environmental watering according to the Murray–Darling Basin Authority (MDBA).
MDBA head of environmental management Carl Binning said the news affirmed the need to use environmental water strategically at the time and volume that provided the greatest benefit.
“48 gigalitres of The Living Murray (TLM) water allocations began to be released from the Menindee Lakes into the Lower Darling about six weeks ago,” Binning said.
“What we’re now witnessing is a large ecological response that would help to re-establish healthy fish populations throughout the southern basin, including the Murray and its tributaries, beyond the next decade.
“Murray cod can live for an amazing 70 years, so the breeding event we are supporting now would continue to benefit the system for many years to come. It is likely to also support recovery from the losses caused by the blackwater event that has followed the flooding in some southern basin rivers.”
Mr Binning said that until recently this part of the Darling had been without flow for many months, due to record low inflows to the Menindee Lakes from the north.
“Since Darling River flood waters have been steadily replenishing the Menindee Lakes, we have carefully timed the use of environmental water allocations to extend those benefits downstream into the Lower Darling.
“The releases are low, averaging 500 megalitres per day, and neither affect the security of water in the lakes’ top two storages, which are important reserves for Broken Hill, Menindee and Lower Darling communities, nor exacerbate flooding in the Murray.
“Local landholders have welcomed the boost to water quality and river health provided by the extra flows. It is a good demonstration of the Basin Plan in action,” Mr Binning said.
To make the most of the major spawning event, a larger pulse using Commonwealth environmental water is being considered to provide essential food and shelter to help the maturing cod larvae to survive. The additional flow would be carefully timed to coincide with the recession of the flood in the River Murray.
The environmental watering event has been a collaborative effort between several government agencies, with water supplied by TLM and delivery coordinated by the NSW Office of Environment and Heritage.
The Living Murray is a joint initiative funded by the NSW, Victorian, South Australian, ACT and Commonwealth governments, and coordinated by the MDBA.