Zebra Mussels (Discovered in Gull Lake in 2010)

(Dreissena polymorpha) 

From the Minnesota DNR website:

Species and Origin: Zebra mussels are small, fingernail-sized animals that attach to solid surfaces in water. Adults are 1/4 to 1-1/2 inches long and have D-shaped shells, often with alternating yellow and brownish colored stripes. Female zebra mussels can produce 100,000 to 500,000 eggs per year. These develop into microscopic, free-living larvae (called "veligers") that begin to form shells. After two to three weeks, the microscopic veligers settle and attach to any firm surface using tiny fibers called "byssal threads." Zebra mussels are native to Eastern Europe and Western Russia and were brought over to the Great Lakes in the ballast water of ships. Populations of zebra mussels were first discovered in the Great Lakes in 1988.

Impacts: Zebra mussels can be a costly problem for cities and power plants when they clog water intakes. Zebra mussels also cause problems for lake shore residents and recreationists; for example, they can:

Attach to boat motors and boat hulls, reducing performance and efficiency.

Attach to rocks, swim rafts and ladders where swimmers can cut their feet on the mussel shells.

Clog irrigation intakes and other pipes.

More Information:

Fact sheet about zebra mussels

Questions and answers about pilot projects to control zebra mussels in public waters

Minnesota Sea Grant (U of M)


A reminder that Gull Lake has zebra mussels and boat owners need to take extra precautions with their boat motors. All boat owners who park their boats and pontoons on the Gull Lake Chain should be sure that all motor lower units are stored OUT OF THE WATER. Zebra mussel veligers (larvae of zebra mussels) may get into motor cooling systems and burn out water pumps and/or ruin the motors. On a recent trip around Gull Lake a number of boats already in the water were noted sitting on lifts with their motors in the lake. To protect your boat motors, all boats should be parked with the lower units out of the water.