For years, Lake Vermilion and Lake Kabetogama seemed special.
As Minnesota’s other large and heavily fished lakes fell one-by-one to zebra mussel infestations, the two sprawling wooded giants in northern St. Louis County remained clean. Many hoped that the unusually low amount of calcium in the two waters made it impossible for the devastating invasive mussels to grow their shells.
Those hopes were dashed recently when the Minnesota Department of Natural Resources said it found zebra mussel larvae in the two lakes, as well as in nearby Crane and Namakan lakes.
The discovery could upend ecosystems and change the way people fish, boat and swim in some of the largest and most widely used lakes in northern Minnesota. Local residents and guides are hopeful, though, that the lakes’ nutrient makeup will stave off devastation.
“It’s very sad,” said Jeff Forester, executive director of Minnesota Lakes and Rivers Advocates. “And it’s preventable.”
Zebra mussels are about fingernail-sized and typically spread when boaters unknowingly pick them up in infested waters and carry them to new lakes. They choke out other aquatic life and damage fish habitat.
With the addition of Vermilion and Kabetogama, the mussels have now spread to all 10 of Minnesota’s largest and most popular fishing destinations, including Lake of the Woods, Mille Lacs, Upper Red, Leech, Winnebigoshish, Cass, Pepin and Rainy lakes.
The “Big 10″ produce nearly half the walleye caught in the state by anglers each year. The lakes account for the majority of the about $2.4 billion spent annually on fishing in Minnesota.