How did zebra mussels get here? <!-- biology, wildlife, invasive species -->
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USGS Frequently Asked Questions
Question:
How did zebra mussels get here?
Answer:
It is generally agreed upon by scientists that zebra mussels entered the Great Lakes from ballast water dumping by large ocean-going vessels from Europe. Ballast water is used to keep ships stable in the water. The amount of water carried is dependent on the amount of cargo on board. A ship will carry large amounts of ballast water when there is no cargo and will dump it in port as cargo is loaded.
