Year Established: 2012 Start Date: 2012-03-01 End Date: 2014-02-28
Total Federal Funds: $19,243 Total Non-Federal Funds: $52,164
Principal Investigators: Jay Stauffer, Jeanette Schnars
Abstract: The round goby is a small benthic fish native to the Sea of Azov, the Caspian Sea, the Black Sea and the Sea of Marmara (Charlebois et al. 1997). Round gobies were first discovered by anglers in the Laurentian Great Lakes in 1990 in the St. Clair River at Saran, Ontario where they are assumed to have been introduced by ballast waters of freighters (Jude et al. 1992, Charlebois et al. 1997). Introduction via transatlantic ballast water is hypothesized to be the vector for many of the recent Pontio-Caspian invaders (Mills et al. 1993). Round gobies were thought to be confined to the St. Clair River until 1993 at which time they were found in the Calumet River near Lake Michigan and in Grand River Harbor Ohio (Charlebois et al. 1997). In 1995, round gobies were found in Western Lake Michigan and Eastern Lake Erie. Since this time, round gobies have spread rapidly to all of the Great Lakes, presumably by interbasin ballast transfer (Clapp et. al 2001). The first round goby found in the Pennsylvania waters of Lake Erie was during a trawl by the Pennsylvania Fish and Boat Commission in 1996 (Chuck Murray PFBC per. com.). Round gobies are now the dominant benthic fish in many of the tributary streams in the Pennsylvania waters of Lake Erie. Round gobies have been found to have detrimental effects on native fish populations in the Great Lakes Region. Preliminary research has implicated them in the extirpation of the mottled sculpin (Cottus bairdi) and the eastern sand darter (Ammocrypta pellucida), and the decline of the Johnny (Etheostoma nigrum) and Iowa darters (Etheostoma exile) (Jansen and Jude 2001, Dubs and Corkum 1996, per. obs.). Round gobies have been found to prey on the eggs of log perch (Percina caprodes) and several other native species (Chotkowski and Marsden 1999). Under experimental conditions, they will prey on rainbow (Etheostoma caeruleum) and greenside darters (Etheostoma blenniodes) (Jude et al. 1995). It is suspected that they compete with native species for food and habitat (Jansen and Jude 2001, French and Jude 2001). Habitat partitioning studies are natural snapshot experiments (Diamond 1986, van Snik Gray and Stauffer 1999). They provide information on habitat requirements of fishes as well as demonstrating habitat shifts in the presence of introduced fishes (van Snik and Stauffer 2001). Although preliminary studies suggest that round gobies are having negative effects on native fishes, no direct evidence has been documented. Habitat partitioning could give direct evidence of this effect. The purpose of this study is to examine partitioning between non-game native benthic Lake Erie stream fishes (darters, madtoms, and sculpins) and to determine if there was a shift in habitat usage of the native fishes when round gobies were present in Twenty-mile Creek. The first year of the study showed that there was a significant shift in habitat use by the native species when Round Gobies were present. We are now proposing to collect native fishes above upstream barriers in the tributaries that to date have prevented colonization of Round Gobies to populations where Round Gobies are present. By sampling the macroinvertebrate fauna, and the stomach contents of native species and Round Gobies we will be able to determine diet shifts associated with the presence of this exotic species.