Copper river chinook salmon inriver abundance.long-term monitoring of adult chinook salmon (oncorhynchus tshawytscha) abundance on the copper river, AK, has been conducted using fishwheels and…

This Cooperative Agreement award, provided by the U.S. Department of the Interior's Office of Subsistence Management under the Alaska Subsistence Management program (CFDA 15.636), will fund long-term monitoring of adult Chinook salmon abundance in the Copper River, Alaska from 2022-2025. The objective is to estimate the inriver abundance of Copper River Chinook salmon such that the estimate is within 25% of the true abundance 95% of the time. The $215,000 award to the Native Village of Eyak will support the operation of fishwheels and two-sample mark-recapture methods to annually estimate the number of Chinook salmon over 500 mm migrating upstream of Baird Canyon. The resulting abundance estimates will be used by federal and state fisheries managers to calculate system-wide escapement and total run size for the Copper River Chinook salmon population.

Copper river chinook salmon inriver abundance.long-term monitoring of adult chinook salmon (oncorhynchus tshawytscha) abundance on the copper river, AK, has been conducted using fishwheels and two-sample mark-recapture methods since 2003. The objective of this study to estimate the inriver abundance of copper river chinook salmon (2022-2025) such that the estimate is within 25% of the true abundance 95% of the time. For the first sample event two live capture fishwheels are operated at baird canyon where all captured chinook salmon will be marked, for the second sample event two live-capture fishwheels are operated below wood canyon near canyon creek and all captured chinook salmon will be examined for marks. Fishwheels are operated for the duration of the chinook salmon run. The number of chinook salmon with a total length greater than 500 MM migrating upstream of baird canyon will be estimated annually using one of two models to generate the abundance estimate: the pooled petersen estimator (PPE) with chapmans correction (ricker 1975 seber 1982) or the darroch maximum likelihood estimator (MLE darroch 1961), in which capture probabilities vary over time. The direct product of the proposed project is the annual inriver abundance estimate of copper river chinook salmon, the usefulness of this data is amplified when combined with harvest data collected by federal and state managers, which allows for a calculation of system wide-escapement and total returningrun size on an annual basis.