Salmonid and Steelhead Population Summary (SPS) and Viable Salmonid Population (VSP) in the Pacific Northwest

The data contained in the SPS database are primarily summary data, compiled at the population level. The database also includes a limited number of series representing the aggregate returns to groups of populations (e.g., Lower Granite Dam counts) or counts of spawners within a subsection of a population where expansions to the population level were not feasible. The information used to develop the population level estimates comes from a variety of sources, but mostly originates from the monitoring programs conducted by state and tribal fishery agencies. The Technical Recovery Teams and NWFSC staff have processed this information to provide an estimate of spawning abundance at the population level. A variety of different types of information (e.g., redd counts, dam counts, carcass surveys, tag recoveries, scale analysis) forms the basis of the information in the database, and where possible the database provides references to these information sources. It is important to recognize that spawning abundance values and other information in the SPS database are not 'facts' that are 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, and the database reports only the best estimates of the values. In all cases there is some degree of uncertainty surrounding these estimates. The NWFSC intends to work with our state and tribal partners to keep the SPS database as up-to-date as possible, and new annual estimates will be added as they become available.

Disclaimer: Due to the wide variety of data sources that go into the SPS database, the NWFSC does not guarantee the accuracy of any of the data in the SPS database. In particular, neither the U.S. Government, nor any agency or employee thereof, makes any warranties, expressed or implied, with respect to the accuracy of the data, including but not limited to the implied warranties or merchantability and fitness for any particular purpose. In no event shall the U.S. Government, nor any agency or employee thereof, be liable for any direct, indirect, or consequential damage flowing from the use of the data in the SPS database.

Demographic data compiled for ESA-listed salmonid populations as part of the NWFSC's technical recovery planning efforts. This project 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. For some populations, additional data fields are also available. The 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.