Zebra Mussels have been found in our lakes and Minnehaha Creek. Without action, they will cover beaches with sharp shells and jeopardize fishing, boating and barefoot walks on the beach.

Zebra mussels are an invasive species. They are small, fingernail-sized mussels that attach to any solid surfaces in water. Adults are 1/4 to 1 1/2 inches long and have D-shaped shells with alternating yellow and brownish colored stripes. They are now found in parts of Lake Minnetonka. Zebra mussels can reproduce rapidly, limit recreational activities and alter aquatic ecosystems.

It is illegal to transport a watercraft or trailer with zebra mussels or aquatic vegetation attached to it on public roads, launch a watercraft or trailer with zebra mussels or aquatic vegetation attached into un-infested waters in the state, possess live zebra mussels or leave zebra mussel-infested waters without draining water from bilges, live wells and bait buckets.

Prevention: Clean, Drain, Dry

Because there are no environmentally safe methods to get rid of zebra mussels, MCWD and the Minnesota Department of Natural Resources are focusing efforts on helping boaters prevent their spread.

Clean: Clean plants, mud, animals and fish from all equipment (boats, trailers, water skis, etc.) that touches the water. Rinse equipment with high-pressure, hot water.

Drain: Drain water from your boat, motor, live well, bait bucket and swimming equipment before transporting it. Do not dump the excess water into storm drains or other bodies of water.

Dry: Dry everything that came in contact with water for at least five days to be sure you have destroyed eggs or young zebra mussels. Store your boat on land if possible.

What should lakeshore and boat owners do?

Zebra mussels will encrust hard surfaces – boat hulls, mooring buoys, inside mechanisms, water toys, docks and lifts. There are precautions boat owners can take to reduce impacts and prevent their spread:

• Run boats long enough to reach operating temperatures. Immature zebra mussels are very sensitive to heat, so a hot engine will kill them as they are flushed through the cooling system. Drain all water reservoirs after each use.
• If possible, store your boat so motors and irrigation intakes are out of the water to prevent encrustation of zebra mussels.
• If it is not possible to store a boat out of the water, contact a marina about protective paints and annual maintenance.
• When taking a boat out of Lake Minnetonka to visit another lake or river, thoroughly clean the boat and trailer inside and out and let it dry for at least five days. Scrape off any encrustations, wash with hot water at high pressure, drain and dry all water reservoirs.
• Clean and decontaminate used docks, structures or water toys before selling them.
• Join the DNR zebra mussel citizen monitoring program. Learn more on the DNR website.
• When swimming or wading, wear protective footwear to minimize cutting feet on zebra mussels’ sharp shells.

MCWD Strategy Prior to Discovery

Prior to the discovery of adult zebra mussels in Lake Minnetonka, MCWD took steps to understand zebra mussels and possible prevention strategies:      

• Research the cost of providing inspectors at public access points to Lake Minnetonka around the clock.
• Provide funding to enhance the Lake Minnetonka Conservation District's public access inspector program. 
• Initiate a zebra mussel habitat suitability assessment of Lake Minnetonka to predict which areas of the lake may be most prone to infestation. 
• Monitor for the presence of Zebra mussels.

What’s Next?

Since the discovery of zebra mussels in Lake Minnetonka, MCWD will continue to work and collaborate with DNR, other agencies and communities.
    
MCWD plans to:  

• Remain vigilant by continuing to monitor Lake Minnetonka and expand our assessment of the extent of zebra mussel presence in the lake.
• Consider expanding our monitoring program to Minnehaha Creek and other District lakes.
• Release the results of our habitat suitability study.
• Support research for zebra mussel control through legislative allocations and possible funding.
• Look for opportunities to reduce zebra mussel habitat (e.g., rip rap and other hard armoring).
• Expand upon existing education efforts to ensure people know that zebra mussels are present in Lake Minnetonka, and what can be done to minimize their spread within the lake and to other lakes.

More Information

• DNR's zebra mussel page
• MCWD's zebra mussel fact sheet
• Save Our Summers brochure
• Lake Minnetonka Habitat Suitability Assessment for Invasive Zebra Mussels (prepared for MCWD)

Zebra mussel expert Dan Molloy's presentation on AIS and his Zequanox treatment: