Michigan Waterfowl Hunters: Help prevent the spread of invasive European Frog-bit

Help prevent your favorite hunting spot from getting choked out by this new aquatic invasive plant by cleaning your boats and gear.

A picture of a lake with an invasive plant

European frog-bit has recently been found in two popular waterfowl hunting locations in West Michigan and hunters are being asked to clean, drain and dry boats and gear thoroughly after each outing to help prevent its spread. This plant quickly forms dense colonies and mats that may prevent native plant growth, make movement difficult for ducks and large fish, and cause problems for hunters, boaters, anglers and swimmers. 

The Department of Environment, Great Lakes, and Energy (EGLE) has confirmed the presence of European frog-bit, a prohibited invasive aquatic plant, in Michigan's lower Grand River immediately upstream of Grand Haven in Ottawa County and in Pentwater Lake near the river mouth in Oceana County. European frog-bit was first detected in southeast Michigan in 1996 and has since spread along the coastal areas of Lakes Erie and Huron up to the eastern Upper Peninsula. The first inland sightings were not until 2016 when it was discovered in Reeds and Fisk Lakes in Grand Rapids. The recent Grand River and Pentwater Lake sightings represent the westernmost occurrences in North America.

European frog-bit thrives in slow-moving waters with little to no wave action and wetland areas. Both Pentwater Lake and the mouth of the Grand River, with its bayous, islands and wetlands, offer ideal habitat for the plant. If you hunt or recreate in these areas, please remove all plants and mud from your gear after you leave these locations. European frog-bit, like many aquatic invasive plants, can spread from one location to another when the plants, plant fragments, resting buds, and seeds get inadvertently transported in watercraft and on gear such as waders, anchors, hunting blinds, decoys, and even potentially on hunting dogs.

New State Law

A new state law requires additional care when transporting boats to prevent the spread of invasive species. 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. Other best practices for hunters include inspection and removal of plant fragments from all gear.

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 yellow center

If you suspect you found European frog-bit in your favorite hunting spot, 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.

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