How Did They Get Here?

The zebra mussel escaped from its homeland in the Black and Caspian seas in the 1700s and emigrated to western Europe. From there, it hitched a ride in the ballast tanks of ships across the Atlantic and through the St. Lawrence Seaway to the Great Lakes. Then adults and larvae spread to the Illinois and Misssippi rivers by barge and boat traffic.

Zebra mussels are now present in El Dorado Reservoir and possibly in the river below the lake.

Unlike other freshwater mussel larvae, zebra mussels don’t attach to fish or other hosts prior to adulthood. Consequently, they can easily spread anywhere that water currents, wildlife, or human activities take them. One of the zebra mussel’s most effective means of dispersion is travelling in bilge water of boats.