Population genetics of Atlantic salmon and brown trout and its relevance for management of genetic resources

Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) are genetically highly structured species. The structuring on a broad distribu-tional scale is the result of the glacial and postglacial history, therefore in Europe several main population groups of Atlantic salmon and anadro-mous form of brown trout, sea trout, have been identified and divergent sources of origin of these groups have been proposed. The pattern of sub-stantial microgeographical differentiation results from the joint action of gene flow, genetic drift, mutation, and natural selection. It is important to understand the effects that the last glaciations have had on the distribution and genetic diversity of these species as well as how selection, genetic drift and gene flow can affect genetic variation within populations and genetic differences between populations in order to fully comprehend the genetic structure of populations and to implement the knowledge for conserva-tion. Genetic management is an important component of strategies that ensure the conservation and recovery of salmon and trout populations.