The zebra and quagga mussels are both considered an invasive or nuisance species, and pose an economic and ecological threat to many areas. They hurt native species by pushing them out of their native habitats. If you were in a boat that was fishing in infested waters, it is important to clean the boat thoroughly before going back into water or transporting the boat to different areas.

Zebra and Quagga Mussels |

Quagga and Zebra Mussels Biology

The zebra mussel, Dreissena polymorpha, is a small freshwater mollusk originally thought to have come from Russia and transported to most of Europe by the 19th century by way of canals and drainages. The zebra mussel had an established population by the late 1980’s in Lake St. Clair in the Great Lakes, most likely entering U.S. waters from European ship ballasts being discharged into the area. The quagga mussel, Dreissena rostriformis bugensis, was noticed at the same time.

Both species are small mussel varieties, growing up to two inches long as adults. Spawning females can produce millions of eggs, and females are able to spawn all year long. The babies in their larval stage freely float, and thus are carried downstream by water currents. Since they reproduce vigorously, they can eat all the food sources for native species. They can live up to five years, and can survive without water if the air humidity is high enough and the outside temperature is cool.

The zebra and quagga mussels clog pipes and get into boat motors. The economic impact on public works such as power stations is monumental as the clean up is long, and once they are established they are difficult if not impossible to eradicate.

Boat Decontamination Procedure

If you were boating in an area known to have zebra or quagga mussel infestation, it is important to decontaminate the boat before putting the boat back into the same or new waters. The U.S. Fish and Wildlife Service has put together the following protocol with five basic steps.

  • Drain the boat at the ramp and eliminate the water from bilges, wet or live wells, or anything else holding water before leaving.
  • Disinfect the engine’s cooling system by running hot water above 140 degrees F for at least one minute through the boat’s motor. This will kill and purge any remaining larvae hidden in the system.
  • Scrub the boat with soapy water, and ensure all hidden areas are reached. Adults can close themselves up to protect themselves from disinfecting scrubs, so step four must be performed.
  • Wash down the boat on all areas that have touched the infested water. A high pressure power hose system with hot water above 140 degrees with a three minute minimum time limit for each area is recommended.
  • Dry the boat thoroughly, by either keeping the boat from water for two weeks if the air temperature is below 70 degrees, and one week if the air temperature is above 70 degrees. If the air temperature is freezing, the dry time is only around three days since both the quagga and zebra mussels have a low tolerance to freezing temperatures.

For more information, visit, a state, provincial and federal agency united effort to prevent the spread of these invasive species to other Western areas of the United States and North America.


Benson, Amy J. “The Exotic Zebra Mussel.” U.S. Fish and Wildlife Service website. 22 April, 2011.

“Western Quagga Mussels.” U.S. Fish and Wildlife Service report. 25 March, 2007. FWS site accessed 22 April, 2011.


Renee Shelton enjoys writing about fish and testing recipes, and serves as webmaster for Dana Point Fish Company. When she’s not handling seafood or out fishing, she can be found in the bakeshop talking about pastry. Visit her at, or send her a message using the contact form above.