Genetic stock identification of overwintering chum salmon in the North Pacific Ocean

Abstract

Understanding stock and age-specific seasonal migrations of Pacific salmon during ocean residence is essential to both the conservation and management of this important resource. Based upon 11 microsatellites assayed on 265 individuals collected aboard international research surveys during winter 2009, we found substantial differences in the agespecific origin of chum salmon (Oncorhynchus keta) in the North Pacific Ocean. Overall, Asian stocks dominated the collections, however, ocean age 1 fish were primarily of Japanese origin and ocean age 2-3+ fish were predominantly of Russian origin. These results suggest that cohorts of chum salmon stocks migrate nonrandomly in the North Pacific Ocean and adjacent seas.

Early Marine Migration of Juvenile Chum Salmon Along the Pacific Coast of Eastern Hokkaido

“…Asian and North American chum salmon stocks mix frequently in offshore waters especially after the first year of ocean life. Pacific Rim genetic baselines have been used to estimate the stock composition of chum salmon caught in the Bering Sea and North Pacific during summer and fall (Kondzela et al , 2016aSato et al 2009a;, and in subarctic waters and the Gulf of Alaska during winter McCraney et al 2012;Urawa et al 2016). These genetic analyses have contributed to estimating the stock-specific distribution and abundance of chum salmon in the ocean and to developing ocean migration models.…”

Bayesian inference from the conditional genetic stock identification model

“…And yet, little or no work has focused on how the structure of reporting groups may lead to bias. Currently, reporting unit proportion estimates are obtained as the sum of their constituent population proportions (McCraney et al 2012;Hasselman et al 2015). This is a reasonable approach, but it does lead to reporting-unit proportion estimates that are demonstrably biased when the number of populations differs between poorly-resolved reporting units (Hasselman et al 2015).…”

Temporal and Spatial Variation in Growth Condition of Pacific Salmon

“…Asian and North American chum salmon stocks mix frequently in offshore waters especially after the first year of ocean life. Pacific Rim genetic baselines have been used to estimate the stock composition of chum salmon caught in the Bering Sea and North Pacific during summer and fall (Kondzela et al 2009(Kondzela et al , 2016aSato et al 2009a;, and in subarctic waters and the Gulf of Alaska during winter McCraney et al 2012;Urawa et al 2016). These genetic analyses have contributed to estimating the stock-specific distribution and abundance of chum salmon in the ocean and to developing ocean migration models.…”