Silver Perch (Bidyanus bidyanus) have been detected in good numbers in the Campaspe and Goulburn rivers for the first time in 10 years, and Murray Cod (Maccullochella peelii) numbers are at a 10-year high in the Broken River system.

This is according to monitoring data collected by the Department of Environment Land Water and Planning (DELWP)’s Arthur Rylah Institute during the delivery of environmental flows. Goulburn Broken and North Central Catchment Management Authorities are delivering environmental flows to improve native fish populations and improve waterway health.

Other fish species monitored during the environmental flow delivery at several sites on the Campaspe, Loddon, Goulburn and Broken rivers in northern Victoria, include the Golden Perch (Macquaria ambigua), Silver Perch and Murray River Rainbowfish (Melanotaenia fluviatilis).

ARI Principal Research Scientist Jarod Lyon said: “The most exciting find was that of Silver Perch, mainly juveniles, which have rarely been detected in the Campaspe River during past surveys.”

“We want to use environmental flows to encourage Silver Perch to take up residence in the Victorian tributaries of the Murray River over the coming years, in line with the basin-wide aims for this important species, and this is a great start.”

“We recorded Silver Perch at four out of five sites in reach four, and at more than half the sites in reach three where they have not been recorded since the monitoring program began in 2007.

“Murray Cod numbers appear to be at the highest abundance recorded from the monitored sites since monitoring started in 2007. Juvenile Murray Cod were recorded from a number of sites on the lower Campaspe River, with these fish likely to be from recent stockings. Future monitoring of these fish will provide important information on survival.”

“The native Murray River Rainbowfish continue to increase in abundance, and are the dominant species in the lower Campaspe River.”

“We are only part way through the monitoring, and follow-up monitoring of the Loddon River and Pyramid Creek will be completed next week.

Environmental flows in the Campaspe, Loddon, Goulburn and Broken Rivers have been subject to long-term monitoring since 2007 as part of the Victorian Environmental Flows Monitoring and Assessment Program (VEFMAP).

The data from all these rivers will be used by scientists to assess how fish populations respond - in terms of their survival, reproduction and dispersal - to environmental water delivery across northern Victorian rivers to demonstrate outcomes as well as guide future water delivery.  

The Victorian Government established VEFMAP to monitor and evaluate the ecological benefit of environmental water use in Victoria. This project is part of a $222 million investment by the Victorian Government to improve the health of waterways and catchments. For more information go to http://delwp.vic.gov.au/water/water-for-victoria