The Iowa Department of Natural Resources (DNR) has confirmed the presence of zebra mussels in Black Hawk Lake near Lake View. A marina operator recently reported the mussels were attached to boat lifts removed from the lake for winter storage. A DNR investigation has identified low numbers on additional boat lifts, but will be monitoring Black Hawk Lake next summer to determine their prevalence and distribution. This confirmation highlights the spread of such aquatic invasive species throughout Iowa. “The zebra mussels in Black Hawk Lake probably arrived on or in a boat that had picked up the mussels from an infested body of water, like nearby Storm Lake,” says Kim Bogenschutz, Aquatic Invasive Species Program coordinator. Young zebra mussels are microscopic and can be unintentionally transported with water in live wells, bilges, ballast or bait buckets. Currently, there is no effective treatment to control the mussels once a lake has been invested. The D-shaped clams have alternating light and dark bands, most are less than one inch long. They are filter feeders that can form dense clusters as they attach to hard, underwater surfaces. An infestation can interfere with the aquatic food chain, kill native mussels, clog water intakes, increase algae blooms and cover beaches with dead shells. Draining all water and cleaning vessels before leaving a water body area is critical to preventing spread.