2010: 5-Year Status Review of Salmon ESUs

Between 1989 and 2007, the National Marine Fisheries Service (NMFS) listed 28 distinct population segments (DPS) of Pacific salmon as threatened or endangered under the Endangered Species Act (ESA).  In 2011, the Northwest and Southwest Fisheries Science Centers conducted a status review update of the listed DPS as part of a 5 year ESA status review of listed salmon, with a particular focus on 1) updated information on ESU/DPS boundaries, and 2) trends and status in abundance, productivity, spatial structure and diversity. One of the notable differences between the current review and the last status review in 2005 was the development of viability criteria for all listed salmon ESUs. In addition to summarizing ESU/DPS status, we also provide some information that will be useful for evaluating trends in threats.  The original listings identified a range of factors that threatened the viability of listed salmon.  Some of these threats, such as harvest, are well monitored and relatively easy to quantify.  Others, such as habitat degradation, are not monitored in a coordinated way across multiple jurisdictions making trend evaluation difficult.  Natural origin abundance of many ESUs/DPSs has increased since the original status reviews in the mid-1990s, but declined since the time of the last status review in 2005. Harvest rates and hatchery production have declined considerably for many ESUs since the early-1990s, and have remained largely stable since 2005.