• Zebra mussels have been confirmed in 29 lakes and nine rivers in Minnesota, and are suspected in 30 additional connected lakes.

• The mussels accumulate on boats and clog motors, litter beaches with razor-sharp shells, and change the ecology of fisheries by consuming food that small fish need to survive.

• They can spread easily, carried in bait buckets or on boats.

• Some people are urging mandatory inspections and boat washing to keep the mussels from being transported carelessly or inadvertently by boaters who move from lake to lake.