A Review Of Stock Assessment Data And Procedures For Us Chinook Salmon Stocks PDF Download

Recent Alaska-wide downturns in productivity and abundance of Chinook salmon stocks have created social and economic hardships across many communities in rural and urban Alaska. There is a fundamental need to more precisely characterize productivity and abundance trends of Chinook salmon stocks across Alaska, gather essential information necessary to understand root causes of these widespread declines, and track population trends into the future. This document outlines a foundation of stock assessment and research programs among a suite of indicator stocks across Alaska designed as a long-term commitment to address fundamental knowledge gaps, elucidate causal mechanisms behind observed trends, and improve management capabilities. A team of nine Alaska Department of Fish and Game biologists and scientists worked collaboratively with federal agencies and academic partners to develop this plan to guide efforts towards better understanding productivity and abundance trends of Chinook salmon. In this plan we describe the general life history of Chinook salmon in Alaska; document stock-specific declines in productivity, abundance, and harvest that have occurred; and, described gaps in knowledge that limit management options when responding to downturns in productivity. The core of this proposed plan is a stock-specific, life history-based approach to research focused on twelve indicator stocks from around Alaska, representing diverse life history and migratory characteristics across a broad geographic range. Stock assessment programs on indicator stocks target specific objectives so that gaps in our knowledge of Chinook salmon can be addressed in a practical, cost-effective, and structured approach. The twelve indicator stocks, from Southeast Alaska to the Arctic-Yukon-Kuskokwim are: Unuk, Stikine, Taku, Chilkat, Copper, Susitna, Kenai, Karluk, Chignik, Nushagak, Kuskokwim, and Yukon rivers. Recommended stock assessments include enumeration of adult escapement and stock-specific harvests in all relevant fisheries, as well as estimates of juvenile Chinook salmon abundance during the smolt stage (Table 1 and Table 2). As a companion to these stock-specific and fishery-based projects, we also recommend a suite of local and traditional knowledge studies (Table 2), nearshore marine surveys, and life history process studies (Table 3). Approximate annual costs by type of activity are shown in Table 4. This plan represents a long-term effort where implementation of stock assessment programs on indicator stocks addresses critical knowledge gaps that limit management capabilities. Implementation to the fullest extent possible provides most opportunity for improved information to assist managers, particularly during times of low abundance.