Zebra mussels found in Crystal Lake

Iowa DNR photo

CRYSTAL LAKE - The Iowa Department of Natural Resources (DNR) is closely monitoring Crystal Lake for zebra mussels after recent discoveries of juveniles in a water sample and two individuals on a sampling plate used to monitor for zebra mussels. No adult zebra mussels were found during a follow-up survey.

The DNR collects water samples and deploys settlement samplers in lakes across Iowa each summer to monitor for the invasive zebra mussel. DNR staff will collect water samples monthly in Crystal Lake this summer, and will survey hard substrate later this summer and fall to determine if Crystal Lake has an established population of zebra mussels.

“Finding zebra mussel veligers and a couple individuals at the boat ramp shows us that zebra mussels have been introduced into Crystal Lake,” said Kim Bogenschutz, the DNR’s Aquatic Invasive Species Program coordinator. “It’s still too early to tell though if there is an established population in the lake.”

The presence of zebra mussels in another lake highlights the spread of aquatic invasive species in Iowa waters. “The zebra mussels in Crystal Lake probably arrived on or in a boat that had picked up the mussels from an infested water body, like nearby Clear Lake,” said Bogenschutz.

Zebra mussels look like small, D-shaped clams that have alternating light and dark bands. Most are less than one inch long. Young zebra mussels are microscopic and can be unintentionally transported with water in bilges, live wells, ballast or bait buckets.  Adult zebra mussels can attach to boats, trailers and aquatic vegetation.

Read the complete story in the July 3 Leader.