Gene flow among pacific harbor seals in northern California

A fragment of the mitochondrial DNA control region was sequenced in 96 harbor seals (Phoca vitulina richardii) from Northern California. This sequence was combined with previously published sequence data from Oregon for analysis in order to investigate female gene flow and detect the presence of genetic population substructure in harbor seal populations throughout this region. Geographic partitioning was not detected; however, phylogenetic structure was revealed in the form of two lineages. Twenty-nine variable sites among 27 haplotypes were identified, nine of which were unique to Oregon. The greatest frequency haplotypes were all weakly detected in Oregon, with the single most highly represented haplotype from Northern California (48%) absent from Oregon. Genetic distances between California and Oregon were significantly different, lending support to the current stock delimitation between Oregon and California. Genetic structure within California indicates more than one California stock designation may be necessary.