What Could Be Hiding in your Lake

Written by Jenna Johnson
Outreach Coordinator with NCCISMA

A European frog-bit is a plant you should fear. It resembles a miniature water lily with heart-shaped leaves about the size of a quarter, but don’t let its delicate size fool you! It can quickly form dense mats which block the sun rays that are needed to help native plants grow. The invasive plant can make movement difficult for ducks and large fish, and cause problems for boaters, anglers, and swimmers. European frog-bit started haunting southeast Michigan in 1996 and has since spread along the coastal areas of Lake Erie and Lake Huron, wreaking havoc all the way up to the eastern Upper Peninsula. Frog-bit does well in slow-moving waters with little to no wave action and wetland areas. European frog-bit can spread from one location to the next if the plant fragments and seeds get moved on watercraft and gear. It is very important to check gear such as waders, anchors, hunting blinds, decoys, and trailers. In fact, aquatic invasive species are so dangerous, a new state law now requires additional care when transporting boats to prevent their spread. This means that boat owners must pull plugs, drain water, and remove plants and debris from their boats and trailers prior to getting on the road.

To identify European frog-bit look for:
– Free-floating leaves with roots hanging below (or sometimes rooted in shallow water).
– Round/heart-shaped leaves that resemble small water lilies (0.5 – 2.25 inches).
– Leaves with a dark purple underside and a spongy area around the center of the leaf.
– White flowers with three petals and a yel low center.

If you suspect you found European frog-bit in your lake, please contact

EGLE Aquatic Invasive Species Program at

EGLE-WRD-ANC@michigan.gov or 517-284-5593.

Or report it online at MISIN.MSU.edu.