Zebra mussel

Zebra Mussels

What is a Zebra Mussel?

The Zebra Mussel, Dreissena polymorpha (Pallas 1771), is a small clam-like animal (mollusk) about the size of an adult's fingernail. Its shell is shaped somewhat like a letter D with dark- and light-colored stripes, hence the name "zebra." The Zebra Mussel is not native to the United States, but rather is native to the colder streams and rivers of Europe. It has been speculated that these mussels were introduced into the United States from the ballast, or waste water, of a European cargo ship traveling in the Great Lakes area.

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Why Should I Care?

Zebra mussels can cost you, the taxpayer, MONEY!!

Zebra mussels multiply rapidly and settle on any hard surface, even on top of each other forming dense colonies. Because there aren't many known natural predators in US waters, these dense colonies can clog municipal, industrial and agricultural water intake pipes and have been known to cause power plants to overheat. On a more personal level, when attached to a boat hull, zebra mussels can create drag making the boat's engine work harder thus lowering fuel efficiency. (It should be noted that most insurance will NOT pay for zebra mussel induced damage to your boat since this type of damage is listed as a preventable problem.)

Zebra mussels filter food from the water and, because they eat so much, they have been known to actually make the water cleaner. This may sound like a good thing, but it can also have an adverse effect on native aquatic species (i.e., fish and mollusks). With less food available, some species may die out. For example, native mussels have been found covered with large zebra mussel colonies. These colonies filter all the food from the water before it reaches the native mussel, essentially starving it to death. Some areas of the Great Lakes have reported a drastic reduction in (or complete elimination of) native mussel populations due to the zebra mussel invasion.

Because of this potential damage to both industry and native aquatic species, some states (i.e., California and Florida) now have laws which make it illegal to knowingly bring zebra mussels into the state.

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What if I see one?

Zebra mussels have been seen in the Wheeler Reservoir of the Tennessee River in North Alabama, but they have not multiplied to the extent seen in northern parts of the country. If zebra mussels aren't in your area yet, they probably will be soon since barge traffic and/or recreational boaters spread the mussels from infested rivers and lakes to uninfested waters.

If you see zebra mussels in any Alabama waterbody:

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What Can I Do to Help?

Zebra mussels attach to any solid surface not protected by antifoulant paints. Veligers (baby mussels), which can not be seen with the naked eye, can also be found in the water of motor cooling systems and can even be transported in bait buckets. (It should be noted that most insurance will NOT pay for zebra mussel induced damage since it is listed as a preventable problem.)

"It will take all of us working together
to slow the spread of zebra mussels in Alabama.

To help prevent unexpected expense from zebra mussel damage and/or to prevent transporting zebra mussels to another area, follow this checklist every time:

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Information on this page was taken from several Auburn University Marine Extension & Research Center brochures and is used by permission. For further information on zebra mussels and what you can do to avoid spreading them into Alabama waters, contact:

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Additional Links:

Zebra Mussel Information Resources
This site has distribution maps, a Zebra Mussel Fact Sheet, and other links related to zebra mussels. From the Florida Caribbean Science Center which is part of the Biological Resources Division of the Geological Survey within the U.S. Department of the Interior.

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Page Curator: Deborah Wills (dwills@HiWAAY.net)
This page has been accessed times since March 12, 1997.
Last Revised: 15 December 1998