Question: are zebra mussels bad for a lake?
Answer: Zebra mussels (Dreissena polymorpha) were first discovered in the Great Lakes in 1988. ... Zebra mussels cost the U.S. economy at least $1 billion annually. They clog water intakes for municipalities and industries, foul boat hulls, motors, water-related equipment and shipwrecks. They can decrease property values.