The year 1993 was also a bad year for influenza, which may also have caused the jump in deaths. The agency will not know whether this is a blip or the beginning of a new trend until the data for the next few years are in. In July 1995, the round goby was found in Duluth-Superior Harbor in Lake Superior. Like the zebra mussel and ruffe, the round goby is native to the Black and Caspian seas. Round gobies were first introduced to the Great Lakes basin in 1990 in the St. Clair River.
Gobies eat aquatic insects, mussels and snails.
They can grow up to a foot long, but specimens found in the Great Lakes so far have not exceeded seven inches. Gobies are considered undesirable because they compete with native fishes for habitat and change the balance of the ecosystem. In August, three ruffe were discovered in Thunder Bay on Lake Huron near Alpena, Michigan, more than 300 miles east of their previously known range. In June, the Ruffe Control Committee of the U.S. Aquatic Nuisance Species Task Force completed a ruffe control program to prevent or delay the spread of the ruffe. The program takes an integrated approach through range reduction, ballast water management, population investigation, surveillance, predator evaluation and education.