This member of the perch family was first discovered in Minnesotas Duluth Harbor, on western Lake Superior, in 1986. Since then, its numbers in the harbor have exploded to several million, and its range has expanded to Wisconsin, Michigan, and Ontario waters of Lake Superior. A native of Europe and Asia, the ruffe has no sport or commercial value because of its small size. It is expected to affect native fish species through competition for food.
Project Leader Tom Busiahn, Ashland, Wisconsin, Fishery Resource Office, explained, "Ruffe are highly-efficient consumers of insects and other bottom dwelling invertebrates, which are also important high-energy food sources for other species, including yellow perch -- the most popular sport fish in the Great Lakes."
U.S. Fish and Wildlife Service (Service) crews from Ashland, Wisconsin surveyed 26 Lake Superior tributaries and coastal locations, one shipping port in Lake Michigan, and seven sites in Lake Huron, including tributaries, shipping ports and coastal locations. A crew from the Service in Amherst, New York, surveyed seven sites in Lake Erie and one in Lake Ontario. The Wisconsin Department of Natural Resources, Ontario Ministry of Natural Resources, and U.S. National Biological Survey also searched Lake Superior for ruffe. Surveys were done at various times, from May through October, in locations deemed likely to be colonized by ruffe. Most surveys were done with trawls, large bag-like nets pulled behind a boat. Other survey methods included electroshocking, seining and gillnetting.
Busiahn noted that, in 1994, ruffe expanded their range more quickly than ever. "Lake Superior warmed up considerably in the mild summer weather this year. This probably helped the ruffe move farther and faster than we have seen before. Also, the Keweenaw Current, which flows from west to east along that shore, may be helping them to move."
Ruffe were found in four new locations in Lake Superior: Chequamegon Bay and Saxon Harbor, Wisconsin, and Black River Harbor and the Ontonagon River, Michigan. These are the first findings of ruffe in Michigan. Ontonagon River, the site of the most easterly capture of ruffe to date, is 180 miles east of Duluth. In addition, two ruffe were collected in Thunder Bay, Ontario, the first capture of ruffe in Thunder Bay since 1991.
Under authority of the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990, a Ruffe control program has been developed and currently awaits approval for full implementation. The goal of the program is to prevent or delay the spread of ruffe through the Great Lakes and inland waters by containing the species to its current range in western Lake Superior. The group overseeing program development and coordination includes scientists and managers from a variety of government agencies, the maritime industry and sport fishing groups. The program is expected to be listed in the Federal Register for public review and comment within the next month.
Ruffe reached North America in the ballast water of an ocean going freighter in the early 1980s. Since 1993, the Great Lakes maritime industry has conducted a voluntary ballast water management plan to prevent ruffe from being spread in the ballast water of Great Lakes ships. Ruffe are believed to have reached Thunder Bay, 180 miles northeast of Duluth, by ballast water around 1990, prior to the industry action.
According to Busiahn, anglers can help prevent further spread of ruffe. "Anglers who catch a ruffe outside of its known range should kill it and report it to their state fish and wildlife agency or the Service. Inadvertent bait bucket transfers of ruffe by anglers also potentially threaten to spread the species to inland waters, and must be prevented through educating the public about the species and the laws concerning it."
To find out about the laws concerning possession of ruffe, consult your states fishing regulations or call your state fish and wildlife agency.
The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 93-million-acre National Wildlife Refuge System which encompasses more than 530 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 66 national fish hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies. For further information about the programs and activities of the U.S. Fish and Wildlife Service in the Great Lakes-Big Rivers Region, please visit our home page at: http://midwest.fws.gov
