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Zebra mussels found in Saylorville Lake

  • 11/6/2024 7:07:00 AM
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The Iowa Department of Natural Resources (DNR) has recently confirmed zebra mussels in Saylorville Lake, after concerned boat owners contacted the DNR while removing their boats from Saylorville for the winter.

Staff with the Iowa DNR confirmed the presence of zebra mussels on multiple boats in the Saylorville Marina area and will conduct additional monitoring around Saylorville Lake next summer to determine the abundance and distribution of zebra mussels.

“The zebra mussels probably arrived on or in a boat that had picked up them up from an infested water body,” said Kim Bogenschutz, the DNR’s Aquatic Invasive Species Program coordinator.

This discovery also serves as a reminder for all boat and lake property owners to check their boats, docks, and lifts for zebra mussels before storing for the winter. To date, zebra mussels have been found in 18 Iowa lakes and nine rivers, mostly downstream of infested lakes, including the Mississippi, Missouri, and Big Sioux rivers.

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. In the case of large infestations, they 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,” she said. “That’s why draining all water is a critical step in preventing the spread of zebra mussels.”

Adult zebra mussels can attach to boats, trailers and aquatic vegetation. Boaters and anglers can help prevent the spread of aquatic invasive species to new water bodies by cleaning, draining and drying their boats and equipment after each time on the water.

  • CLEAN any plants, animals, or mud from your boat and equipment before you leave a waterbody.
  • DRAIN water from all equipment (motor, live well, bilge, transom well, bait bucket) before you leave a waterbody.
  • DRY anything that comes into contact with water (boats, trailers, equipment, boots, clothing, dogs). Before you move to another waterbody either: Spray your boat and trailer with hot or high-pressure water; or Dry your boat and equipment for at least five days.
  • Never release plants, fish or animals into a water body unless they came out of that waterbody and always empty unwanted bait in the trash.

It is illegal to possess or transport aquatic invasive species or to transport any aquatic plants on water-related equipment in Iowa. Iowa law also requires boaters to drain all water from boats and equipment before they leave a water access and to keep drain plugs removed or opened during transport. It is also illegal to introduce any live fish or plants, except for hooked bait, into public waters.

Learn more about aquatic invasive species, including a list of infested waters in the current Iowa Fishing Regulations or at www.iowadnr.gov/ais.

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