SPIRIT LAKE – Juvenile zebra mussels have shown up attached to boat hoists removed this fall from East Okoboji, West Okoboji and Lower Gar lakes. This discovery comes after four juvenile zebra mussels were found in East Okoboji Lake and Upper Gar Lake, last fall.

Mike Hawkins, fisheries biologist for the Iowa Department of Natural Resources, said he was contacted by a lake service provider in the Iowa Great Lakes on Nov. 1st after the contractor spotted suspicious shells attached to a boat hoist.

“After closer examination it became evident that many of the recently removed hoists had juvenile zebra mussels attached,” Hawkins said. “I suspected that other hoists from the area may have zebra mussels attached as well.”

Summer monitoring for zebra mussels resulted in little evidence of an expanding population, but effective sampling is difficult when populations are low.
“Inspection efforts are continuing on hundreds of boat hoists and should provide additional information on the extent of the infestation within the Iowa Great Lakes,” Hawkins said.

As the infestation develops it will be important for boaters to clean, drain and dry their boats and equipment before moving from the Iowa Great Lakes to other bodies of water. It is required by law for boaters to remove all invasive species and to drain all water from boats and equipment before leaving a waterbody.

The Iowa Great Lakes Association remains committed to finding a solution. We will keep you informed.