The Corangamite Catchment Management Authority (CMA) and Barwon Water are supporting an environmental monitoring program which will assess the health of the Upper Barwon River to guide its future management.
The organisations have engaged the Department of Energy, Environment and Climate Action’s Arthur Rylah Institute to conduct electrofishing surveys over the next two years to understand the health of fish populations in the waterway.
Arthur Rylah Institute scientist Lauren Johnson said that electrofishing involves passing an electrical pulsed current through the water, momentarily stunning fish so that they can be netted, identified and weighed.
The process, which is used throughout the world, is considered harmless for both fish and the environment.
“Fish recover quickly and are released back into their environment unharmed,” Ms Johnson said.
“The Arthur Rylah Institute uses this fish survey method to monitor fish species across Victoria as part of a number of monitoring projects including the Victorian Environmental Flows Monitoring and Assessment Program (VEFMAP) and the Native Fish Report Card Program.”
The surveys will enable baseline understanding of fish populations and river health that can be used as a reference point for any future work and decision making.
More than 20 community members attended an electrofishing demonstration event at the end of February, when sampling was undertaken at several sites along the Barwon River from Forrest to Winchelsea.
On the day, sampling found mainly native species and included Short-finned Eel, Obscure Galaxias, and Southern Pygmy Perch.
Barwon Water Managing Director, Shaun Cumming, said that Barwon Water was supporting the survey with $80,000 in funding, aligned to the commitment in its 2030 strategy to deliver a healthier environment for all.
“We know how much our customers and the local community value the environment and healthy local rivers, which is one of the reasons we’re pleased to support this work,” Mr Cumming said.
“The data gathered over the next two years will help get the best outcome for the upper Barwon River into the future.”
Corangamite CMA CEO, Amber Clarke, said that the fish sampling information would help inform future management decisions and provide a baseline for comparisons to any future sampling work.
“This data is an important snapshot in time of the status of fish populations in the Barwon River,” Ms Clarke said.
“When these surveys are repeated, we’ll be able to track if populations are improving in response to the collective efforts made by landholders, government agencies, citizen scientists, Traditional Owners and Landcare groups to improve the health of the Barwon River.”
Ms Johnson said that highlights from the surveys taken along the Upper Barwon River were evidence of successful River Blackfish recruitment and finding a good population of Obscure Galaxias at one sampling site despite the presence of small barriers.
In part, information gathered in the surveys will help inform the Corangamite CMA’s decision-making on environmental flows for the Barwon River.
Corangamite CMA decides the timing of environmental releases down East and West branches of the Barwon River from West Barwon Reservoir based on water available via the Upper Barwon River Environmental Entitlement 2018.
The entitlement provides an average of 1,000ML per year and up to 2,000ML of the total storage capacity at full supply to help preserve vulnerable aquatic species and support the health of the flow-stressed waterway.
