State begins treatment at Clear Lake for invasive aquatic plants

Throughout the winter, the Iowa Department of Natural Resources will monitor applications of an approved herbicide, in very low doses, to the water at Clear Lake to eradicate invasive plant species.

Eurasian watermilfoil and curly-leaf pondweed are non-native plants that are easily spread to wetlands and other lakes. The plants can also impact recreation on the lake.

Scott Grummer, a fisheries management biologist at Clear Lake with DNR said the herbicide, Sonar A.S., will only impact the non-native plant species because it is being applied during a season when native aquatic plants have already died back.

Grummer said DNR went out in a handful of boats in early November to spread the herbicide in strips through the center of the lake. He said they let “Mother Nature do that initial mix