Salmonid and Steelhead Population Abundance Summary from 1949 to 2010 for Washington, Oregon, and Idaho

The Northwest Fisheries Science Center's (NWFSC) Salmon Population Summary (SPS) database provides public access to demographic data compiled for ESA-listed salmonid populations as part of the NWFSC's technical recovery planning efforts. The database contains data collected by co-managers (WDFW, ODFW, IDFG, and Tribes) and compiled in cooperation with NWFSC staff for: spawning abundance, age structure of wild spawners, fraction of natural spawners that are of wild origin, and the reduction in spawning abundance due to harvest. For some populations, additional data fields are also available.

Abundance of ESA-listed salmonids.

These data correspond to the populations identified by the NMFS Technical Recovery Teams, and are used in part to assess population and ESU-level recovery criteria for many listed ESUs. Most importantly, this data is critical for informing 5 year ESA salmon reviews, and makes 5 year status review data available to the public and addresses the legal mandate to complete status review for listed salmonids.

The table contains data on spawning abundance, age structure of wild spawners, fraction of natural spawners that are of wild origin, and the reduction in spawning abundance due to harvest.

None. The data is available to the public.

The raw information on which the spawning abundance estimates were developed consist of numerous types of data including redd counts, dam counts, carcass surveys, information on prespawning mortality, and spawning distributions within populations that the TRTs used to develop estimates of natural-origin spawning abundance.

All of the Pacific Northwest TRTs spent considerable time and effort developing spawning abundance data for the populations they identified within ESUs. In almost all cases these estimates are derived from state, tribal, or federal monitoring programs. The raw information on which the spawning abundance estimates were developed consist of numerous types of data including redd counts, dam counts, carcass surveys, information on prespawning mortality, and spawning distributions within populations that the TRTs used to develop estimates of natural-origin spawning abundance. It is important to recognize that spawning abundance estimates and related information such as the fraction of spawners that are of natural origin are not known with certainty. Rather, they are estimates based on a variety of sources of information, some known with greater precision or accuracy than others. Ideally these estimates would be characterized by a known level of statistical uncertainty; however, for the most part such a statistical characterization is either not possible or has not been attempted.

The data were compiled by NMFS West Coast Region staff from various data sources.