Northwest Fisheries Science Center

Technical Recovery Team: Willamette/Lower Columbia

WLC-TRT Viability Report

Welcome to the home page for the WLC-TRT's Interim Report on Viability Criteria For Willamette and Lower Columbia Basin Pacific Salmonids (March 2003). This page provides links to the Viability document itself, programs used in the report and reference material used in the report.

The report was prepared by the Willamette/Lower Columbia Technical Recovery Team (WLC-TRT) as a technical foundation for the development of delisting criteria in the WLC. This report is a complete synthesis of the WLC-TRT's work on the topic to date, but is titled "Interim" to indicate that the report does not reflect final delisting criteria. Development of final delisting criteria will require additional policy-technical interaction, and this report is one step in that process. Additional technical analysis and policy interaction may result in modified WLC-TRT recommendations as recovery planning progresses. Work is currently underway through the Willamette/Lower Columbia ESA Executive Committee (the recovery planning policy group for the domain) to develop interim recovery goals using TRT viability criteria and comanager recovery goals. When draft recovery plans are completed, they will undergo formal public review and comment before being finalized.

Link Descriptiona
Viability Report Cover Letter Cover letter transmitting the viability document from Usha Varanasi, Director NWFSC to Bob Lohn, Director of NOAA Fisheries Northwest Region. The cover letter describes the context and purpose for the viability report.
Viability Report Download viability report, or sections of the report, as PDF files.
SimSalmon SimSalmon is a computer program with a number of modules that can be used to estimate salmon population summary statistics and population risk analyses. The program was used to estimate population variance estimates for Appendix E of the viability report.
PCC Calculator PCC Calculator is a computer program for generating population change criteria (PCC) viability targets (see appendix D of viability report for description of PCC).
Abundance data for WLC populations Time series of abundance, hatchery fraction, harvest, and age structure for WLC populations. Data were used to estimated recent abundances in Appendix D and variance in Appendix E.
Stratum Average Tables Tables showing all possible combinations of population status within a stratum and the stratum average associated with each combination. These tables are referenced on page 14 of the viability document.