COMPETITION AMONG RIVERINE SPORT FISH INFERRED FROM GUT CONTENT ANALYSIS
Rising stream temperatures associated with climate change are predicted to affect the distribution of fish species, potentially leading to novel competitive interactions. The purpose of this study was to examine dietary interactions between a warm water fish species, smallmouth bass (Micropterus dolomieu), that is likely to increasingly come into contact with cold water species such as brown trout (Salmo trutta). A secondary objective was to assess interactions between wild and stocked brown trout, as stocking also potentially affects resident cold water fish species. We predicted that diets would be similar between bass and trout and between stocked trout and wild trout. Diet items were obtained from 41 fish using gastric lavage, enumerated and categorized to the lowest taxonomic resolution possible (usually family or order), then analyzed statistically using non-metric multidimensional scaling (NMDS). Results showed little diet overlap between bass and trout, but nearly complete overlap between stocked and wild trout. We infer that smallmouth bass likely have minimal impact on food availability for brown trout in this stream, while stocked trout appear likely to directly compete with wild trout.
Eli Beal (Primary Presenter/Author), Indiana University of Pennsylvania, email@example.com;
David Janetski ( Co-Presenter/Co-Author), Indiana University of Pennsylvania, firstname.lastname@example.org;