Using Riverscape Genetics to Inform Conservation of Eastern Brook Trout Populations

Brook Trout (Salvelinus fontinalis) in headwater stream networks are largely sedentary with many individuals remaining in the same stream reach for months at a time.  Fine scale genetic structuring is commonly observed in Brook Trout populations due to infrequent movements, and headwater populations are often assumed to function independently when separated by unsuitable mainstem habitat.  Although dispersal among headwaters may be rare, such movements are important for maintaining genetic diversity and increasing long term viability of otherwise isolated populations.  Identifying features on the landscape that limit connectivity, therefore, will allow for more biologically relevant restoration prioritization strategies beyond those that attempt to maximize ‘miles upstream’.  Genetic techniques can be used as a tool for evaluating these relationships by relating genetic patterns to landscape scale variables. In this study genetic data were collected from over 30 headwater streams in Connecticut and used to delineate genetic structuring and dispersal rates among headwater populations.  A suite of riverscape genetic analyses were then used to evaluate which anthropogenic and natural landscape features best described genetic relatedness. We will use the results of this study to construct decision support tools to prioritize restoration projects based on the likelihood of reestablishing upstream and downstream landscape-scale connectivity.