Evaluating Re-Colonization of Coho Salmon and Steelhead Following Landscape-Level Removal of Barriers in Coastal Northern California

Restoration practitioners and natural resource agencies strive to predict the benefits of fish passage barrier removal projects, and the potential for barrier removals to improve fish populations by restoring access to blocked habitat. The NOAA Restoration Center is working through its Open Rivers Initiative to develop a nationwide monitoring program that will evaluate physical project implementation  and landscape scale fish response to barrier removal projects.  In Northern Coastal California, the NOAA Restoration Center is participating in several fish passage barrier removal projects that are expected to result in immediate recolonization by anadromous salmonids.   The barriers have completely blocked anadromous salmonid access for many years.  The projects are being monitored before and after barrier removal to assess the rate and extent of coho salmon and steelhead recolonization in these newly opened watersheds.  Pre- and post- project Adult spawner and juvenile electrofishing surveys are being conducted to quantify changes in anadromous fish numbers, use and distribution.  The surveys are helping to improve the NOAA Restoration Centers understanding of salmonid response to barrier removal in Northern Coastal California.   Lessons learned from these efforts will provide valuable information to guide future project prioritization and restoration expectations as well as inform the larger nationwide Open Rivers monitoring effort.