Estimating The Abundance Of Sacramento River Juvenile Winter Chinook Salmon With Comparisons To Adult Escapement PDF Download

Transgenerational genetic mark–recapture (tGMR) methods will be used to estimate the spawning abundance of Chinook salmon Oncorhynchus tshawytscha at the Chilkat and Unuk Rivers in 2020 and 2021, respectively. Tissue samples from adults returning to the Chilkat River were collected in the summer of 2020 and from parr rearing in the Chilkat River in the fall of 2021. Lab work and data analysis will be completed in the winter of 2021–2022. Similarly, tissue samples from adults returning to the Unuk River were collected in the summer of 2021, and samples will be collected from parr in the fall of 2022. Lab work and data analysis will be completed in the winter of 2022–2023. These studies will be used to determine the feasibility of using tGMR to estimate escapement in Southeast Alaska by comparing tGMR abundance estimates to abundance estimates generated through existing field programs. This operational plan covers the lab and project reporting aspects of these projects. Primary data collection activities are described in the project-specific operational plans.