Modeling Chinook Salmon Returns to the Kuskokwim River, Alaska, 1976-2009

As with many large river systems, the Kuskokwim River of Western Alaska has a diverse array of independent monitoring projects used to assess salmon harvest, escapement, and the impact of fishery management actions. Individual projects with limited spatial and temporal scales fall short of addressing most broad scale management needs such as assessing exploitation rate, changes in productivity, effects of selective harvest practices, and the impacts of incidental harvest from interception fisheries. However, pooling such data for Kuskokwim River Chinook salmon has allowed for development of a retrospective total in-river run reconstruction that effectively addresses these broad scale issues. We combined historical data from harvest, tributary escapements, mark-recapture investigations, and habitat information into a maximum likelihood estimation model to estimate total Kuskokwim River in-river Chinook salmon returns from 1976-2009. The resulting annual abundance estimates will allow for analysis of stock-recruit dynamics, management performance, development and assessment of drainage-wide escapement goals, trends in age-sex-size composition, and climate effects.