Genetic Rescue in Fragmented Populations of Brook Trout - presentation by A. Whiteley
Advanced Topics in Conservation Genetics Webinar Series. Presented by Dr. Andrew Whiteley, Department of Environmental Conservation, University of Massachusetts Amherst. February 10, 2015. Fragmentation effects on natural populations are pervasive and have wide-ranging management implications. I will focus on native populations of the brook trout in eastern North America and discuss fragmentation effects on headwater stream systems from a genetics and evolutionary perspective. Brook trout populations are highly fragmented, particularly in the southern portion of the native range. We have demonstrated that this leads to small, genetically depauperate populations that are likely to have lower resilience to environmental change. We are initiating a genetic monitoring program that will help identify population strongholds and isolated populations that are currently at most jeopardy. The effective number of breeders (Nb) is a genetic metric that appears to be extremely promising in this regard. Once the most threatened populations are identified, a possible management action involves the movement of a small number of individuals form a nearby source population, so-called genetic rescue. We have an ongoing experimental test of genetic rescue underway in a series of four brook trout populations in Virginia. I will summarize these results from this experimental work and discuss genetic rescue in the context of additional management options to maintain population resilience.
