Dobosenski, Jamie2018-11-282018-11-282018-08https://hdl.handle.net/11299/201013University of Minnesota M.S. thesis. August 2018. Major: Integrated Biosciences. Advisors: Thomas Hrabik, Jared Strasburg. 1 computer file (PDF); v, 39 pages.Increasing our understanding of aquatic invasive species is important because of the negative influence they can have on the economies and ecosystems of invaded regions by negatively affecting ecotourism as well as commercial and recreational fisheries. There is growing interest in how environmental variability (e.g. temperature) and stochastic invasion events (e.g. founder effect) affect the genetic composition of populations of invasive species. Rainbow smelt (Osmerus mordax) are a cold-water, planktivorous fish that spread into the Great Lakes basin in the early 1900s. We performed genetic analyses using microsatellites to determine if a temperature induced mortality event affected the genetic structure of a population of invasive rainbow smelt and to also investigate the influence stochastic invasion events have had on the genetic composition of invasive rainbow smelt populations across broad geographic ranges. Overall, there was no genetic difference in rainbow smelt collected before, during, or after the temperature induced mortality event. To investigate the influence stochastic invasion events have on populations of invasive rainbow smelt, we conducted population genetics analyses on rainbow smelt specimens from Lake Ontario, Lake Michigan, Lake Superior, and four inland lakes in Northern Wisconsin. Most population pairs had pairwise Fst values significantly different than zero except two comparisons. Based on clustering analysis and PCoA analysis, four distinct population clusters were identified. Overall, this study provides evidence that founder effects have more of an impact on invasive rainbow smelt population diversity than extreme population reductions.enFisheriesGeneticsInvasivesLaurentianPopulationsSmeltThesis or Dissertation