Local Adaptation of Coho Salmon Following Reintroduction to the Interior Columbia River

Coho salmon were extirpated from the inland reaches of the Columbia River system by the construction of hydro-power dams inhibiting migration, habitat destruction, and overharvest.  Efforts have been ongoing to re-establish naturally spawning coho salmon in the Yakima and Wenatchee rivers using lower Columbia River broodstock.  Over the course of several years the reintroduction program has progressed from being completely dependent on lower river broodstock fish to utilizing a combination of natural origin and hatchery returns as broodstock.  Currently, the Wenatchee population of coho salmon is reproducing naturally without input from downstream source stocks.  In this study, we utilize RAD (Restriction-site Associated DNA) sequencing data to examine genetic variation within and among year classes of coho salmon from the Wenatchee River (2000 – 2011) to test for adaptation of this stock to local environments.  Thousands of SNPs will be used to test for both neutral and adaptive divergence over time between source stocks and newly established fish in this system.