Integrating Fish Movement Data and Hydraulics for Habitat Analysis

Understanding the impacts of levee repair on fish is challenging because of the range of physical variability and diverse fish species and life stages that are potentially present.  The biological response to different levee repair options was evaluated in the Sacramento River, CA using field data collection and the Eulerian Lagrangian Agent Method (ELAM).  This method simulated fish movements by combining computational fluid dynamics model outputs and computer generated fish movement.  Fish movement was calibrated using 2D fish tracks collected in the same area.   The ELAM created an environment where virtual fish were allowed to swim in response to the fine-scale hydrodynamics and choose their destination.  After calibration, several scenarios were evaluated that included varying amounts of instream woody material.   The fish movement model provides managers and stakeholders with a means to examine fine scale behavior and develop alternative management scenarios.  The model results were valuable in understanding how the use of instream woody materials alters behavior of fish in the Sacramento River.  Future work will focus on utilizing ELAM modeling techniques in planning activities at other locations in the Sacramento River and developing behavior models for different species. This will allow refinement of other levee repair designs, maximizing effectiveness while reducing costs.