Zebra mussel (Dreissena polymorpha) is a mollusk pest. It is a native of Caspian Sea region of Asia and was first detected in Lake St. Clair, Michigan in 1988.
Zebra mussels (Dreissena polymorpha) are small, fingernail-sized mussels. They are believed to have been transported to the Great Lakes via ballast water from a transoceanic vessel. Since that time, they have spread rapidly to all of the Great Lakes and waterways in many states, as well as Ontario and Quebec. This pest poses a large risk to U.S. plant health. International commerce provides recognized avenues of introduction.