5-Year Review: Summary and Evaluation of Central Valley Spring-run Chinook Salmon ESU

Many West Coast salmon and steelhead (Oncorhynchus sp.) stocks have declined substantially from their historic numbers and now are at a fraction of their historical abundance. There are several factors that contribute to these declines, including: overfishing, loss of freshwater and estuarine habitat, hydropower development, poor ocean conditions, and hatchery practices. These factors collectively led to the National Marine Fisheries Service (NMFS) listing of 28 salmon and steelhead stocks in California, Idaho, Oregon, and Washington under the Federal Endangered Species Act (ESA). The ESA, under Section 4(c)(2), directs the Secretary of Commerce to review the listing classification of threatened and endangered species at least once every five years. After completing this review, the Secretary must determine if any species should be: (1) removed from the list; (2) have its status changed from threatened to endangered; or (3) have its status changed from endangered to threatened. The most recent listing determinations for west coast salmon and steelhead occurred in 2005 and 2006. This document summarizes NMFS’s 5-year review of the ESA-listed Central Valley (CV) spring-run Chinook Salmon Evolutionarily Significant Unit (ESU). 2011 NMFS (National Marine Fisheries Service) SWR (Southwest Region) Submitted Public Domain 1862