Zebra Mussels

Zebra mussels colonize hard surfaces like this submerged anchor. Photo courtesy of Kerry Crowningshield.

The zebra mussel is a small freshwater mollusk native to the Black and Caspian Sea regions. First discovered in the Great Lakes in 1988, it is thought that they were transported to North America in the ballast tanks of ships. Since then, the mussels have spread throughout much of the eastern half of the United States.

Zebra mussels were first discovered in the southern part of Lake Champlain in 1993. Since then, the State of Vermont has tracked the spread of zebra mussels northward as part of the Long Term Water Quality and Biological Monitoring Program. Since 1993, zebra mussels have spread throughout nearly all of Lake Champlain. The Vermont Department of Environmental Conservation also monitors for zebra mussels on inland lakes.

Juvenile and adult zebra mussels can attach themselves to any hard surface in great numbers. Zebra mussels clog water intake pipes, foul boat hulls and engines, obscure archeological artifacts, and can also negatively affect the aquatic ecosystem. They have also contributed to a decline in the Lake’s population of native mussels. Unfortunately, studies around the world have yet to yield effective strategies for controlling zebra mussels once they have been introduced. Spread prevention to protect areas currently without zebra mussels remains the top priority for zebra mussel management.