How do zebra mussels affect recreational users?

The following information  is provided by
For more information, contact the  Lake Viking Association Office.

  • Boaters - Recreation-based industries along Lake Erie have been impacted by zebra mussels. Unprotected docks, breakwalls, boat bottoms, and engine outdrives were rapidly colonized beginning in 1989. Consequently, there were numerous reports of boat engines overheating due to colonies of zebra mussels clogging cooling water inlets and mussels colonizing boat hulls. 
  • Swimmers - Beaches are also affected by zebra mussels. The sharp-edged mussel shells along swimming beaches can be a hazard to unprotected feet. By autumn of 1989, extensive deposits of zebra mussel shells were on many Lake Erie beaches. The extent of these deposits varied with successive periods of high wave activity. 
  • SCUBA Divers – One of the things that attract people to dive underwater are the many features such as shipwrecks, various fish species and underwater landscapes. Since zebra mussels attach to hard surfaces, many of the features are at risk of becoming obscured. 


National Sea Grant Network Exotic Species Graphics Library
Zebra mussels attached to shipwreck’s wooden hull.
Photo by Chet Childs 

National Sea Grant Network Exotic Species Graphics Library
Foot deep windrows of zebra mussel
shells on western Lake Erie beach.
Photo by J. Ellen Marsden,
Lake Michigan Biological Station

National Sea Grant Network Exotic Species Graphics Library
Mussels on the lower unit of an inboard/outboard engine.
Photo by Steve Krynock