Seascape genetics of saithe (Pollachius virens) across the North Atlantic using single nucleotide polymorphisms

The identification of isolated populations in widely distributed marine species is often impeded by low levels of genetic differentiation. However, modern genetic approaches now allow for the efficient detection of potentially large numbers of novel genetic variations, thereby improving the
power to identify biologically meaningful management units. To investigate the genetic structuring of saithe (Pollachius virens L.), we applied seascape genetic approaches to 131 single nucleotide polymorphism loci genotyped in 584 fish collected from 11 locations across the North Atlantic. Wombling analysis and the Monmonier algorithm revealed four genetic clusters (Barents Sea, Central Northeast Atlantic, Rockall, and Canada) across the species distribution range. These results imply that genetic structuring in saithe maybe influenced by abiotic factors such as geographical distance, and bathymetry aswell as biotic factors such as sex-biased migration, and natal homing. The results suggest a potential mismatch between management and biological units across the Northeast Atlantic, which may have implications for sustainable exploitation of the species.