Oral Presentation Australian Freshwater Sciences Society Conference 2022

Exploring the disconnect: Flow, barriers, and basin-scale fish connectivity across regulated river systems (#27)

Danial Stratford 1 , Steve Marvanek 2 , Rocio Ponce Reyes 3 , Brenton Zampatti 2 , Sam Nicol 3
  1. CSIRO, Black Mtn, ACT, Australia
  2. CSIRO, Urrbrae
  3. CSIRO, Brisbane

River regulation can result in a broad range of negative outcomes for ecological systems, and amongst these are changes in flow regimes and loss of connectivity. For fish, impacts can include a loss of movement triggers, a miss-match in timing of flows and movement behaviour, as well as constraints to movement from physical barriers. Here we explore the interaction of the flow regime, barriers and the movement characteristics of Murray cod and silver perch using the integration of an extensive barrier dataset and large-scale hydraulic model. The basin-scale model considers the limitations to longitudinal connectivity at large-spatial scales, including timing and magnitude of flows and barrier drown-out. We use species movement kernels to explore, identify and map locations where movement ability is reduced, and where improving fish movement can be supported through flow management to remediate impacts and improve ecosystem function at large spatial scales.