Zebra and Quagga Mussels

Zebra (Dreissena polymorpha) and Quagga Mussels

Where did they come from?

• Originated in the Black and Caspian Sea in Europe.
  

• They made their way to the United States in 1988 into the Great Lakes from incoming ships.>

Where can they be found in South Dakota?

• Veligers (immature larvae) were possibly discovered in the Missouri River below Ft. Randall and Gavin's Point Dams in 2003. No adults have been found in South Dakota.

What do they look like?

• Zebra Mussels are usually less than one inch long, and have a D shaped shell.
• They vary from solid light brown, dark brown, and striped.

Why are Zebra Mussels a problem?

• They can reach high densities causing problems for water intakes, docks, boat motors, and infrastructure.
• They filter vast quantities of water for microscopic organism, potentially altering the entire food web within a water body.
• Zebra Mussels cannot be controlled once they establish themselves in a body of water, but you can prevent them from spreading to other bodies of water.

How are Zebra Mussels spread?

• Zebra Mussels are most commonly spread by human transport by recreational equipment.
• Just because you can't see the Zebra Mussels doesn't mean they aren't there. Zebra Mussel larvae can only be identified with the use of a microscope.

Check out Aquatic Nuisance Species Prevention on ways to prevent the spread of Aquatic Nuisance Species

Zebra Mussel links

Link to Protect You Waters info on Zebra Mussels
USGS Fact sheet on Zebra Mussels
Pictures of Zebra Mussels
South Dakota Zebra Mussel Distribution Map

Click here to report Zebra and Quagga Mussels