The silver perch (Bidyanus bidyanus) is a nationally threatened native fish species found in lowland rivers of the Murray Darling Basin. Populations have declined in abundance and range, due to factors such as altered flow regimes and fragmentation. In this project, we use acoustic telemetry to investigate immigration of silver perch into tributary streams of the Murray River, and the role of streamflow, including multi-river coordinated environmental flows, in facilitating movement. This information is needed to improve our understanding of movement ecology, particularly the effects of flows on movement, and to ensure environmental water entitlements are used to achieve the best environmental outcome with the water that is available. Preliminary results suggest that immigration may be an important driver of population dynamics, with this process linked to patterns of hydrology. Based on the findings, appropriately designed and coordinated environmental flows, across river networks and large spatial-scales could be represent an important targeted management action to promote tributary fish population recovery for the species.