Microsatellites reveal clear genetic boundaries among Atlantic salmon (Salmo salar) populations from the Barents and White seas, northwest Russia

Fourteen microsatellite loci were employed to study the genetic structure of 34 Atlantic salmon ( Salmo salar ) populations from the White and Barents seas area, the last major European region where the species has remained in its natural state. The populations were separated into four distinct clusters (Atlantic Ocean and western Barents Sea, Kola Peninsula, western White Sea, and eastern Barents Sea) within which genetic divergence varied between 0.02 and 0.10 as estimated with FST. When this structuring was contrasted with previously identified mtDNA-based groupings, a remarkable similarity was observed, implying that these four groups can be considered as a good starting point for defining management units in the region. Indeed, several approaches for assessing every population’s conservation value suggested that conservation of populations from each observed cluster would maximize preservation of the region’s genetic diversity. Furthermore, each unit may require differing management strategies, as distinct patterns of genetic diversity and divergence characteristics were detected. In addition, individual assignment success within a region was high (87%–96%), indicating that the data can be used as a baseline to differentiate individuals caught in offshore fisheries on a regional level with a relatively high degree of accuracy.