Fish monitoring undertaken throughout November and December has shown a major breeding response from native fish in the River Murray with the largest numbers of golden perch (callop) larvae recorded in the last eight years.
The Department for Environment and Water’s (DEW) Manager Environmental Water, Tony Herbert said recent high flows in the system as well as the delivery of water for the environment has 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,” Tony 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.”
Associate Professor Qifeng Ye, Inland Waters Principal Scientist with the Department of Primary Industries and Regions’ (PIRSA) South Australian Research and Development Institute (SARDI), said species like callop and silver perch are cued to spawn by elevated spring flows and then eggs and larvae drift 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.
“They really thrive in these higher flow conditions so these results are a great example of why flows at the right time of year are so important to support spawning and survival of a new generation of fish.
“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.
“Future monitoring will confirm whether larvae survive and recruit into the lower Murray population.”
Monitoring in the South Australian Murray is collaboratively supported by DEW, PIRSA, the Commonwealth Environmental Water Office (CEWH) and the Murray-Darling Basin Authority.
Water for the environment has been delivered to the river courtesy of CEWH and The Living Murray Program.