Skeena River Steelhead as a Model for Characterizing Intra-Specific Diversity in Anadromous Salmonids

Defining reference points for the protection of intra-specific diversity in harvested salmonids is a problem that continues to challenge fisheries managers.  Selection of any biological unit above the population is a compromise between traditional optimized management and the full representation of within-species variation.  Current fisheries management needs to consider this trade-off explicitly to ensure that the breadth of adaptive potential is preserved, particularly in a time of rapidly changing environments. We used a variety of methods to create steelhead ‘Conservation Units’ (population aggregates) for the Skeena River of northern British Columbia.  Specifically, we combined an assessment of genetic differentiation with habitat and life history analyses to develop units that represent a range of genetic and ecological diversity, but that remain practical for managers.  Our approach enables identification of Conservation Units within major ecological drainage units independent of other areas, and is readily transferrable to other regions or broader jurisdictions. The approach is consistent with the Canadian federal Wild Salmon Policy in its effort to recognize key elements of intra-species diversity.