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European Frogbit

European frogbit (Hydrocharis morsus-ranae) is a free-floating aquatic plant that can quickly choke shallow ponds, open marshes, ditches, and edges of lakes. Dense layers of interlocking plants and dangling roots can interfere with swimming, boating, fishing, and waterfowl hunting. European frogbit can displace native aquatic plants and deplete dissolved oxygen levels, impacting fish and wildlife. Following escape from cultivation in Ontario in 1932, it spread along the Ottawa, Rideau, and St. Lawrence rivers into the northeastern U.S. It has also spread to shorelines of lakes Ontario, Erie, St. Clair, and Champlain and to inland lakes in Washington, New York, and Michigan.

European frogbit can spread to new waters through improper disposal by water gardeners and by clinging to watercraft, trailers, and equipment. It spreads naturally when plant pieces break off and float on water currents. Plants regenerate each spring when overwintering vegetative buds (turions) float to the surface and grow rapidly into tangled mats of interlocking plants. Eradicating established infestations is nearly impossible. Your help detecting and reporting new infestations is vital for preventing their spread.

What you can do:
Learn to identify European frogbit (see back cover).
Inspect and remove aquatic plants and animals from boat, motor, and trailer.
Drain lake or river water from livewell and bilge before leaving access.
Dispose of unwanted plants in the trash.
Never dump aquatic plants from one body of water into another.

Report new sightings - note location; wrap a specimen in a wet paper towel, place in a sealed plastic bag; and call a U.S. Fish and Wildlife Service office: WI (715) 682-6185, NY (716) 691-5456, MN (612) 713-5114.

REMINDER: Know the rules!
Specimens are needed to confirm sightings, but some jurisdictions prohibit or discourage possession and transport of European frogbit and other invasive aquatic plants and animals. Contact your local natural resource management agency for instructions. Unauthorized introduction of fish, crayfish, or plants into the wild is illegal. Protect your property and our waters.

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