AWRI Thum

Student Summer Scholars Project: Round gobies

Population genetic structure of the invasive round goby in Lake Michigan: implications for natural versus anthropogenic dispersal after introduction



The following is an abstract from a paper in review (as of April, 2010) that resulted from independent undergraduate student research (Michael Ben Stacey and Elizabeth LaRue).



Understanding the subsequent dispersal of non-native species following their original introduction is important for predicting the extent and speed of range expansion and is critical for effective management planning and risk assessment. Post-introduction dispersal may occur naturally or via human transport, but assessing the relative contribution of each is difficult for many organisms. In summer 2009 as a Student Summer Scholars project, I collected data using seven microsatellite markers to study patterns of dispersal and gene flow among 12 pierhead populations of the round goby (Neogobius melanostomus) in Lake Michigan. Working with Dr. Thum and Dr. Ruetz, we found a surprising degree of population structure among sampling sites within this single Great Lake.  Patterns of genetic differentiation are related to geographic distance along stretches of both the eastern and western shorelines, but are interrupted over the whole lake.  We found average genetic differentiation among populations to exhibit a strong negative correlation with amount of shipping traffic.
We suggest that the observed genetic patterns result from limited natural dispersal and frequent long distance dispersal through anthropogenic dispersal mechanisms such as shipping. Our study suggests that though gobies can disperse and found new populations through natural dispersal mechanisms, its rapid spread within and among the Great Lakes has most likely been aided heavily by massive transport via ships.  

 


Page last modified April 5, 2010