Photo/Minnesota Sea Grant

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About the Great Lakes

Notre Dame's Department of Biological Sciences

Notre Dame aquatic ecologists led by Gary Lamberti, associate professor of biological sciences, have determined that enough worms, midges and mayflies exist in the eastern Great Lakes to sustain an incursion from Lake Superior by the Eurasian ruffe (pronounced "rough"), a small, perch-related fish that reproduces quickly and has few predators.

Ever since the appearance of the ruffe in Lake Superior almost a decade ago, after being carried in the ballast water of a European ship, researchers have worried that the species will outcompete yellow perch, a popular sport fish whose populations are already in decline in Lake Michigan. The researchers now predict that within the decade the ruffe will move down into Lake Michigan, as well as into lakes Erie, Huron and Ontario. One study suggests that the ensuing competition between the perch and ruffe will likely eat into both species' populations.

"Exotic species, such as ruffe, now represent one of the greatest global threats to natural ecosystems," Lamberti says.