In 1988, a ship discharged its ballast water into Lake St. Clair, Michigan, releasing billions of organisms that it had taken on at a freshwater port in Europe. In the ballast were the larvae of a freshwater mollusc, the zebra mussel (Dreissena polymorpha). This small mussel is usually no more than 5 cm long with characteristic zebra-like stripes (Figure 1). The zebra mussel is native to the Caspian Sea and Ural River in Asia. In the nineteenth century, it spread west and now is found in most of Europe, the western portion of Russia, neighboring former Soviet Union republics, and Turkey.
Note - This chapter is largely extracted from the work by Miller, Payne, and McMahon (1992)
Spread of zebra mussels in this country