Hydrography and population genetic structure in brook charr (Salvelinus fontinalis, Mitchill) from eastern Canada

Despite the abundance of studies of genetic diversity in freshwater fishes, few have specifically addressed the role of habitat structure in partition ing genetic variance within and among populations. In this study, we analys ed the variability of six microsatellite loci among 24 brook charr populati on samples in order to correlate hydrographic structure with genetic organi zation. These populations originated from three Canadian National parks (Ko uchibouguac, Fundy and Forillon) that showed distinct hydrographic structur e. Considering the general characteristics of these habitats, we formulated specific hypotheses in regard to genetic structure, which were principally based on the potential for gene flow and population size associated with e ach habitat. The hierarchical analysis of molecular variance and the geneti c distances computed among populations revealed that habitat structure anal yses constitute an important, but insufficient predictor of genetic structu re. We discuss the importance of habitat complexity on genetic structure in the context of management and conservation.