The Iowa Department of Natural Resources (DNR) recently confirmed that zebra mussels are in Black Hawk Lake.
A marina operator reported finding zebra mussels on boat lifts removed from the lake for winter storage. Investigation by DNR staff discovered low numbers of zebra mussels on additional boat lifts. DNR staff will conduct surveys at Black Hawk Lake next summer to monitor the abundance and distribution of zebra mussels in the lake.
The documentation of zebra mussels in another lake highlights the spread of aquatic invasive species in Iowa waters. “The zebra mussels in Black Hawk Lake probably arrived on or in a boat that had picked up the mussels from an infested water body, like nearby Storm Lake,” said Kim Bogenschutz, the DNR’s Aquatic Invasive Species Program coordinator.
Zebra mussels look like small, D-shaped clams that 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. Large infestations may interfere with aquatic food chains, kill native mussels, clog water intakes, increase algae blooms, and cover beaches with dead shells. Currently there is no effective treatment to control zebra mussels once they have infested a lake.
Young zebra mussels are microscopic and can be unintentionally transported with water in live wells, bilges, ballast or bait buckets. Adult zebra mussels can attach to boats, trailers and aquatic vegetation.
It is illegal to possess or transport prohibited aquatic invasive species, such as zebra mussels, in Iowa. Boaters must also drain all water from boats and equipment before they leave water access and must keep drain plugs removed or opened during transport.
“Boaters and anglers can unintentionally spread zebra mussels and other aquatic invasive species if they do not take the proper precautions –