Viability criteria for steelhead within the Puget Sound distinct population segment

Under the U.S. Endangered Species Act (ESA), the National Oceanographic and Atmospheric Administration's National Marine Fisheries Service (NMFS) is required to identify measurable and objective delisting criteria as part of recovery planning. These delisting criteria must describe the conditions under which a listed species or distinct population segment (DPS) is no longer in danger of extinction (endangered) or likely to become so in the foreseeable future (threatened). We define a viable DPS as one that is unlikely to be at risk of extinction in the foreseeable future; for this purpose, we adopted the viable salmonid population (VSP) criterion of a 100-year timeline (McElhany et al. 2000, Viable Salmon Populations and the Recovery of Evolutionarily Significant Units, NOAA Tech. Memo. NMFS-NWFSC-42) to evaluate risk of extinction. Ultimately, the identification of delisting criteria requires the consideration of technical analyses relating to viability, which are contained in this report, and policy decisions such as acceptable levels of risk, which are not. It presents the biological viability criteria recommended by the Puget Sound Steelhead Technical Recovery Team (PSS TRT). The framework and the analyses it supports do not set targets for delisting, nor do they explicitly identify specific populations or groups of populations for recovery priority. Rather, the framework and associated analyses are meant to provide a technical foundation for those charged with recovery of listed steelhead (Oncorhynchus mykiss) in Puget Sound, from which they can develop effective recovery plans at the watershed scale (and higher) that are based on biologically meaningful criteria. [doi:10.7289/V5/TM-NWFSC-129 (http://dx.doi.org/10.7289/V5/TM-NWFSC-129)] Jeffrey J. Hard, James M. Myers, Edward J. Connor, Robert A. Hayman, Robert G. Kope, Gino Lucchetti, Anne R. Marshall, George R. Pess, and Bradley E. Thompson. "May 2015." Available also in electronic format on the Internet. Includes bibliographical references (pages 129-136). 2015 NMFS (National Marine Fisheries Service) NWFSC (Northwest Fisheries Science Center) Library http://doi.org/10.7289/V5/TM-NWFSC-129 Public Domain 1864