by Scott Brown
Introduced to the North American Laurentian Great Lakes region in the late 1980s or early 1990s via the ballast water of a trans-oceanic freighter that had entered our freshwater inundated region via the St. Lawrence Seaway, round goby (scientific name: Neogobius melanostomus) are a highly adaptive, rapidly reproducing bottom dwelling fish that is native to the Black and Caspian Sea region. Capable of thriving in a wide range of salinity levels as well as in freshwater ecosystems, the highly invasive round goby often grows to lengths of over seven inches, and are capable of achieving body weights of up to three ounces.
Since their inadvertent introduction to the Great Lakes region nearly forty years ago, exotic invasive round goby have successfully invaded each of the Great Lakes as well as many of their major tributary rivers and streams. Round goby were also recently discovered in at least one of upstate New York’s Finger Lakes in addition to eastern New York state’s Hudson River. Moreover, several of Michigan’s well known large inland lakes have also undergone successful invasions by the pesky aquatic invader from Eurasia.
Characterized by voracious appetites, round goby aggressively feed upon aquatic insects, snails, and it is most important to note, large volumes of the developing eggs of native fish. Species such as largemouth and smallmouth bass, bluegill (photo), redear sunfish, and pumpkinseed, keystone species in most of the moderately productive inland lakes of Michigan, that create gravel and stone layered spawning nests with their fins in mid-to-late spring are particularly vulnerable to having their eggs eaten by the hyper-aggressive exotic invader.