Gobies are native to the Black and Caspian Seas. They were transported to the Great Lakes through ballast water, and were first discovered in North America in the St. Claire River (north of Detroit) in 1990. Since then, they have spread to eastern and southern Lake Erie, southern Lake Huron, southern Lake Michigan, and western Lake Superior. (22). |
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D. Jude, NOAA |
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Gobies
have reproduced rapidly in the Great Lakes. The species has several
characteristics that enable them to out-compete native fish species
for both food and habitat, including aggressive behavior, an ability
to withstand
poor water quality conditions (even feed in complete darkness), and
a long spawning season. (22). Their
niche is similar to the native mottled sculpin, but because of their
aggressiveness, the round goby has caused the local extinction of
the sculpin from several
areas of the Great Lakes (1). Scientists are also worried
about the potential for pressure on lake trout, as the gobies have
been seen
to prey upon trout eggs and fry. |
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The
presence of zebra mussels has facilitated the spread of the round
goby, demonstrating “invasional meltdown” as
described by Ricciardi (13). The round
goby is one of very few fish that can eat zebra mussels,
so they have a large food supply and little competition for food. Also,
zebra mussels accumulate on the lake floor, forming a benthic habitat
that is home to small invertebrates, another source of prey for the
goby (1). |
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