We have completed 6 years of research across a diversity of water year types in the butte sink sutter bypass and sacramento rivers

This Cooperative Agreement award, funded by the U.S. Department of the Interior's Fish and Wildlife Service under the Central Valley Project Improvement Act (CFDA 15.648) program, provides $400,241.00 to the University of California, Davis (UC Davis) to monitor fish populations and food webs in the Sutter National Wildlife Refuge and Sacramento River region of California.

The primary objectives of this one-year award (March 2025 - February 2026) are to: 1) Continue monitoring the regional fish assemblage and food webs to better understand how juvenile salmon utilize the Sutter National Wildlife Refuge; 2) Develop an environmental factor-based decision tree to help manage the refuge for both fish and wildlife; and 3) Coordinate with refuge staff to understand water operations and fish passage, including monitoring PIT-tagged fish using a network of detectors. This research builds on 6 years of prior work studying water conditions and fish habitat across the Butte Sink, Sutter Bypass, and Sacramento River region.

In 2024 we continued to monitor the regional fish assemblage and food webs to better understand how juvenile salmon utilize the sutter national wildlife refuge. The primary focus of the 2025 wateryear will be focused at the snwr to develop an environmental factor based decision tree to help manage the refuge for both fish and wildlife. We will continue to monitor water conditions and food web structure on the snwr. We will coordinate with refuge staff to better understand water operations and fish passage. We will have PIT tagged fish that will be monitored using a network of detectors that will allow US to better understand the interplay between water operations and infrastructure primarily between rice board with and without holes for fish passage.