The Effects of Culverts On Brook Trout Genetic Diversity

Recent developments utilizing genetic tools have recognized habitat fragmentation as a potential stressor to the long term viability of fish populations.  Culverts are believed to be a source of habitat fragmentation and are currently classified in terms of passability for fish passage based on physical attributes; however little known genetic data supports these passage classifications. Culverts in the Upper Shavers Fork, West Virginia were identified, surveyed and classified using select fish passage criterion.  Currently, five streams have been identified:  two streams with culverts classified as impassable, two streams with culverts classified as passable, and a stream with no culvert.  Tissue samples from brook trout (Salvelinus fontinalis) were taken above culverted stream sections as well as the control stream in June 2012.  Genetics results to date, utilizing six out of 13 microsatellite loci, indicate significant genetic differentiation (F_ST = .039,  p < .02) between brook trout populations inhabiting a stream with a culvert and no genetic differences between populations on either side of the passable culvert (F_ST = .014, p = .17).   Expected results from this study will assist managers in prioritizing culvert restoration sites based on genetic data rather than expected movements based on physical characteristics of the culvert.