A multi-Agency fish monitoring program in the River Murray has uncovered a major breeding response from native fish, recording the largest numbers of golden perch (callop) larvae in the past eight years.
Manager of Environmental Water at the Department for Environment and Water (DEW), Tony Herbert said the program was a collaboration between DEW, the Department of Primary Industries and Regions’ (PIRSA), the Commonwealth Environmental Water Office and the Murray-Darling Basin Authority.
Mr Herbert said recent high flows in the system as well as the delivery of water for the environment had benefited native fish breeding.
“Improved flows in the system have likely contributed to the breeding success, creating conditions conducive to the spawning of callop and silver perch, and the survival of their eggs and larvae,” Mr Herbert said.
“Widespread rain in the catchment has resulted in good spring flows to South Australia this year and these have been enhanced by adding environmental water to the natural events, boosting the outcomes for native fish.”
Inland Waters Principal Scientist at PIRSA and Associate Professor at the South Australian Research and Development Institute (SARDI), Qifeng Ye said species like callop and silver perch were cued to spawn by elevated spring flows and then eggs and larvae drifted downstream with the flow.
“For long-lived fish like callop, these breeding events are really important as they do not occur every year,” Dr Ye said.
“The monitoring is undertaken by scientists from SARDI inland waters research team, who found increased numbers of eggs and larvae across multiple sites in the lower River Murray,” she said.
“Future monitoring will confirm whether larvae survive and recruit into the lower Murray population,” Dr Ye said.
