Early warning program battles frog bit, other invasive species

by Lacee Shepard

A Department of Natural Resources (DNR) early warning program is preventing the invasive species frog bit from destroying native aquatic plants.

“Essentially, frog bit is an invasive plant that’s come into Michigan from Canadian waterways,” said Holly Vaughn, a DNR wildlife outreach technician. “It’s roughly the size of a quarter or half dollar, it looks like a mini- water lily but forms really dense mats of leaves on the surface of the water and ends up choking out native species of plants.”

European frog bit is Photo: Department of Natural Resources.

European frog bit is choking the native species around it. Photo: Department of Natural Resources.

An invasive species is one that comes from another ecosystem and can harm native plants and animals  There are more than 200 invasive plants and animals in Michigan that could have been controlled or prevented had the program started earlier, said Susan Tangora, invasive species coordinator for the DNR Wildlife Division.

The Early Detection Rapid Response Program, which received $970,000 over three years from the federal Great Lakes Restoration Initiative,  is one of the most cost-efficient ways to prevent the spread of invasive species, Tangora said. To control them, they need to be caught quickly.

The program gets ahead of the problem by quickly assessing areas of infestation and examining the extent of damage, Tangora said.

The DNR submits samples of invasive species to labs at the University of Michigan or Michigan State University.

“Then we look at our control options,” said Tangora.  Frog bit t can be controlled with herbicides and  hand removal.

Neither is a silver bullet solution, she said.

“We have tested in combination both hand pulling and herbicide applications,” she said. “We’re starting to assess our success rate.”

The program uses crews from the AmeriCorps Stewardship program  and the Michigan Civilian Conservation Corps.  Right now, they are focusing their removal efforts in Southeast Michigan.

Among the invasive species the program has battled are plants like parrot feather, Brazilian elodea, water lettuce, water hyacinth and flowering rush.

“We have rangers in the parks that are trained on herbicides and trained on identification and help with invasive plants,” said Tom Tucker, a stewardship ranger with the DNR’s Parks and Recreation Division at Island Lake Recreation Area in Brighton.

“Every year we like to focus on a few species because that’s all we can do,” Tucker said.

The counties with the most frog bit are Monroe, St. Clair, Macomb, Bay and Wayne.

European frog bit is a problem because it chokes out native species and can even impede boats from moving.

The DNR suspects recreational boating spreads it,  Tangora said.

“We believe it has moved through the Great Lakes system,” she said. “The most invasive species are facilitated and moved by humans and animals.“

The program has removed 1,500 pounds of frog bit from state waterways, said Tangora. But it grows fast and is hard to control. “In a season, an infestation can multiply exponentially, and in a county there are probably thousands of pounds of frog bit.”

“The good news is it’s only in those counties, so if we can keep it there and keep it from spreading and work on reducing those populations, we will have a good fighting chance from it spreading throughout Michigan,” she said.