Genomic insights into local adaptation and migration success in reintroduced Coho Salmon of the Wenatchee River basin

Journal Article · 20 May 2025 · Transactions of the American Fisheries Society

DOI: https://doi.org/10.1093/tafafs/vnaf019 · OSTI ID:2568176

Horn, Rebekah L.; Caisman, Jeff; Kamphaus, Cory; Narum, Shawn R.

ABSTRACT Objective Reintroduction of salmonids into regions where they have been extirpated is a common conservation strategy that is often implemented through natural recolonization, translocation of natural populations, or hatchery-based programs. Locally adapting to specific environmental conditions is critical for long-term population viability, particularly for species like Coho Salmon Oncorhynchus kisutch, which face diverse selective pressures during their migration. This study focused on the mid-Columbia River Coho Salmon reintroduction program managed by Yakama Nation Fisheries, which has successfully reintroduced Coho Salmon into the Wenatchee and Methow River basins, Washington. Notably, these populations have adapted to the longer migration route than those in the founding stock, with selection favoring individuals with an earlier arrival time and that can navigate a 15-km, high-gradient canyon to reach optimal spawning grounds. The objectives of this study were to investigate whether specific genomic regions are under selection for traits associated with return location and timing in Coho Salmon. Methods Low-coverage whole-genome resequencing data were used to screen for genomic regions associated with the phenotypes of interest. Results A weak polygenic signal in female Coho Salmon was found to be associated with return group, with a subset of candidate adaptive regions occurring across eight chromosomes. Conclusions These findings provide insights into the genomic mechanisms underlying local adaptation in reintroduced salmon populations and inform broodstock selection strategies aimed at promoting natural production and long-term population sustainability.

• Sponsoring Organization: USDOE
• OSTI ID: 2568176
• Journal Information: Transactions of the American Fisheries Society, Journal Name: Transactions of the American Fisheries Society; ISSN 0002-8487
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United States
• Language: English