Where did zebra mussels come from?
Zebra Mussels are originally from the Caspian Sea region of Northern Iran, Azerbaijan, southern Russia, Kazakhstan, and Turkmenistan. Due to extensive trade between this region and Europe during the 17th and 18th centuries they were able to spread. Zebra mussels were carried with the trade vessels to Europe and spread throughout the continent, reaching the Isle of Great Britain by the 1830’s. When large ships head out on to the open ocean, they need to carry weight, called ballast, to remain stable. If the ship is not transporting cargo, that ballast is water. This water is picked up in the homeport carried with in the ship and dumped out as they prepare to load cargo. So whatever is in the ballast can travel thousands of miles before being released into new waters. Zebra mussels were first discovered in Detroit’s Lake St. Clair in 1988. They would have been brought there in ballast water, survived, and reproduced to a number where they were noticed. Since then they have spread by atta
