Population genetic structure of Alaskan Pacific ocean perch (Sebastes alutus)

Abstract

Knowledge of the population structure of a species is essential for its effective management and sustained production. Although Pacific ocean perch (Sebastes alutus, POP) is an important species both economically and ecologically, little is known about its population structure and life history in Alaskan waters. The objectives of this study were to describe the population structure of POP in terms of the numbers and geographic scale oflocal populations, their connectivity, and the compatibility of that structure with current management. Fourteen micro satellite loci were used to characterize the population structure genetically in eleven geographically distinct collections from sites along the continental shelf from the Queen Charlotte Islands to the Bering Sea. In spite of the many opportunities for most life stages to disperse, there was strong geographically related genetic structure (Fst =0.0123, p <10⁻⁵). Adults appear to belong to neighborhoods that exchange genetic information at relatively small spatial scales (14 to 90 km). Although this suggests limited movement, connectivity is evidenced by the isolation-by-distance relationship, the apparent northwestward movement of gene flow in the Gulf of Alaska (GOA), and the break in geneflow in the central GOA. The observed population structure has a finer geographic scale than management areas, which suggests that current fisheries management should be revisited.