What: The zebra mussel is a freshwater mollusc with a yellow/brown dark and light colored striped shell. It can grow up to two inches long, is usually found in shallow (6-30 foot) algae-rich water, and grows in clusters.Originated From: The Caspian Sea region.
How it arrived: The zebra mussel was brought in by ballast discharge from oceangoing ships.
It's spreading to: The zebra mussel was first discovered in Lake St. Clair, near Detroit, Michigan in 1986. It has since spread to the Great Lakes, the Mississippi River, The Hudson River, the Ohio River, and the Upper Susquehanna River. Map of Zebra Mussel's progression.
Threat: Zebra mussels have a rapid reproductive rate and a high rate of survival.
Damage: These mussels tend to clump together and can causing clogging of pipes and waterways. They consume so much food and oxygen that there is not enough left over for other species.
Control: Chemicals are a possible method of control. On an individual level, people should take care not to track them from one body of water with their boats.