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Impacts of Invasive Species
Dreissenidae are a family of freshwater molluscs which are considered an invasive species in many countries. The most common type of dreissenid is Dreissena polymorpha, also known as the Zebra mussel. It is believed that these mussels were first introduced in North America sometime in the 1980's after being brought to the Great Lakes in a foreign ship's ballast water. Since its introduction this invasive species has been found in approximately 30 U.S. states and some areas in Canada.