Two species of Asian carp (silver and bighead) escaped from southern aquaculture facilities into the Mississippi River in the early 1990s and have become the most abundant species in some portions of the river.
Steadily moving northward, Asian carp have been spotted some 40-50 miles from Lake Michigan. The Chicago Ship and Sanitary Canal connects the Mississippi River to the Great Lakes.
Asian carp can grow to 100 pounds, and natural resource managers fear the large fish could become a dominant species if it invades the Great Lakes.
Eurasian Ruffe Gymnocephalus cernuus
Eurasian ruffe are small members of the European perch family. They were first discovered in Duluth harbor in 1985.
Ruffe have spread to other rivers and bays around Lakes Superior and have established a population in Thunder Bay near Alpena, Michigan.
In some areas, ruffe have shown explosive population growth and have displaced valuable native species such as yellow perch as well as emerald shiners and other forage fish. Their sharp spines make them difficult for larger fish to eat.
Round Goby Neogobius melanostomus
Round gobies are a bottom-dwelling fish that can reach 10 inches in length. They have been known to steal bait from fishing lines and are unintentionally caught by anglers.
Round gobies were first discovered in the St. Clair River in 1990 and have spread rapidly in the Great Lakes and some inland lakes.
Once established, gobies can displace native fish, eat their eggs and young, take over optimal habitat, spawn multiple times per season and survive in poor quality water.
Sea Lamprey Petromyzon marinus
Sea lamprey are predatory eel-like fish that are native to the coastal regions of both sides of the Atlantic Ocean. They entered the Great Lakes through the Welland Canal in the 1920s.
Sea lamprey are found in high concentrations in northern Lake Huron, spawning in the St. Marys River and other northern Michigan tributaries.
Sea lamprey prey upon native fish and have had a devastating impact on lake trout. Part of the mission of the Great Lakes Fishery Commission is to control the invasive sea lamprey.
Aquatic Invasive Species Poster Series
Colorful illustrations, photos and graphics help 4th – 8th grade students understand why invasive species are a problem and what can be done.
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Colorful illustrations, photos and graphics help 4th – 8th grade students understand why invasive species are a problem and what can be done.