Eurasian Ruffe (Gymnocephalus cernuus)
Eurasian Ruffe
The Eurasian ruffe (rhymes with tough) may pose a serious ecological threat to water environments and to sport and commercial fishing. This invader may compete with native fish for food and habitat. First reported in western Lake Superior in 1986, the ruffe population has rapidly increased in the St. Louis River at Duluth-Superior and spread to other rivers and bays along the south shore of western Lake Superior.
There is a great concern over the potential for the ruffe to expand its range in North American waters. Early detection of isolated populations may help slow or restrict the spread of the Eurasian ruffe. Your help is vital to prevent the spread of ruffe and to report new sightings.
Identify Eurasian Ruffe
General Characteristics
- Very slimy when handled
- Usually less than 6 inches (15 cm long
- Perch-like body shape
What You Can Do
- Always drain your livewells, bilge water, and transom wells before leaving the water access.
- Never empty your bait bucket into the water, always empty it on land.
- Never dip your bait bucket into a lake or river if it has water in it from another
- Never dump live fish from one body of water into another
- If you catch a ruffe outside the Duluth area of Lake Superior or the St. Louis estuary, kill it, freeze it, and call the MN Department of Natural Resources Invasive Species Program in St. Paul, 1-888-MINNDNR, or Doug Jensen of Minnesota Sea Grant. Do not throw it back alive!
Warning:
Never transport a live Ruffe. States have differing regulation and penalties regarding possession and/or transportation of live or dead ruffe. Know your state statutes.
Doug Jensen
