Michigan DNR fighting frog-bit: Response to new invasive species under way in Alpena, Bay and Chippewa counties

The Michigan Department of Natural Resources' Wildlife Division is leading response efforts to control a new aquatic invasive plant, European frog-bit (Hydrocharis morsus-ranae). Until recently, this free-floating plant had only been reported in a few localized sites in the southeastern Lower Peninsula. Through recent statewide monitoring efforts, this species has been detected in Saginaw Bay, Alpena and Munuscong Bay in Chippewa County.

This new invasive species was detected as a result of an Early Detection Rapid Response (EDRR) pilot project funded through a federal Great Lakes Restoration Initiative grant. The project relies on collaboration with partners, including Michigan State University and Cooperative Weed Management Area groups.

Using the new State of Michigan’s Rapid Response Plan for Aquatic Invasive Species, developed jointly by the DNR, DEQ and MDARD, these new reports were verified, an on-site assessment was conducted and a response plan was formulated. Control measures are under way, including physical removal (1,500 pounds removed beginning in mid-September) and trial treatments with herbicides.

“Responding quickly to a new invasive species is critical to increasing our chances of success, and it requires a well-organized, collaborative effort between multiple agencies and other partners,” said Wildlife Division chief Russ Mason.

Education, outreach and future control activities are being planned with local stakeholders and partner groups. A complete outline of the EDRR program, including future stages, is defined in the newly revised SOM Aquatic Invasive Species State Management Plan at www.michigan.gov/aquaticinvasives.

European frog-bit was accidentally released into Canadian waters between 1932 and 1939, and has since spread throughout Ontario, New York, Vermont and other eastern states. It forms extremely dense vegetative mats that cover the available open water surface. Frog-bit shades out submerged native plants, reducing invertebrate and plant biodiversity, disrupts natural water flow, inhibits watercraft movement and may adversely affect fish and wildlife habitat.

European frog-bit resembles a miniature water lily (lily pad), with leaves about the size of a quarter or half-dollar. It produces a small white flower, usually in June. Frog-bit is typically found in slow moving, shallow waters (1-3 feet), typically within cattail and bulrush stands. Additional identification information is available at the Midwest Invasive Species Information Network at www.misin.msu.edu.

If you suspect that you’ve seen European frog-bit, report sightings to www.misin.msu.edu or to Matt Ankney, EDRR coordinator, at ankneym2@michigan.gov or (517) 641-4903.

For more information, please visit www.michigan.gov/invasivespecies.