Environmental flows are increasingly being used to restore native fish populations in flow degraded rivers. Providing environmental water is a significant investment, therefore it is critical to evaluate its effectiveness in achieving the intended outcomes for native fish. The Victorian Environmental Flows Monitoring and Assessment Program (VEFMAP) was established by the Victorian Government to monitor and assess ecosystem responses to environmental watering in priority rivers across Victoria. VEFMAP includes a strong focus on monitoring key processes that govern fish populations. Here we present preliminary results from an assessment of native fish dispersal (movement) in response to environmental flow delivery in a Northern Victorian River system.

We used two methods to assess fish movement responses to flow throughout the Loddon River and Pyramid Creek. First, we explore the movement of golden perch using acoustic telemetry to assess the role of flows and other factors in governing dispersal. Secondly, we assess how the entire fish community respond to specific environmental watering events by monitoring fishways before, during and after the delivery of environmental freshes. The management implications of this work include the potential use of environmental flows to enhance colonisation of native fish species throughout the Murray Darling Basin.