The coastal fens of northern Michigan
The northern shores of Lake Huron are home to teal-blue waters, sun-bleached coasts of ancient bedrock, and plants that eat meat.
Michigan’s dynamic geological past is famously shaped by glaciers, whose retreat thousands of years ago carved the Great Lakes and defined its borders. Equally influential in its formation were the oceans that covered this region millions of years ago, and the Petoskey stone — our state stone and one of many fossilized corals found here — is proof of that history.
Even more evidence lies in the coastline itself: broken limestone that’s actually compressed layers of calcium-rich skeletons from ancient sea creatures that lived here well before the age of dinosaurs. Those mollusks and corals may be long dead, but the sedimentary rock they left behind eventually became the coastal fens that are now home to Michigan’s carnivorous plants.
Coastal fens are flat, low-lying areas of shallow bedrock on or near the Lake Huron shoreline. They are one component of karst topography, a limestone-dominant landscape where sinkholes, caves and groundwater-fed springs are also found.
The thin soil found here contains very few nutrients, so plants like butterwort, bladderwort, sundew, and pitcher plants have adapted to life in this rugged habitat by eating insects, much like the well-known Venus flytrap of the eastern U.S.
“These are really cool carnivorous plants,” said Heather Huffstutler, land protection director
for Huron Pines. “They’re not going to get nitrogen from the soil so they’re going to look for it in other places.”
As their name suggests, pitcher plants use specialized cupped leaves filled with fluid to trap, drown, and digest flies and other insects. Sundews and butterwort attract bugs like flypaper with sticky-sweet hairs covered in nectar. Bladderwort, which have no roots and float freely in shallow pools, catch tiny aquatic insects in submerged traps.
In areas of fens where better soil is available, water-loving wildflowers like the yellow lady’s slipper, fringed gentian, bog stars and Indian paintbrush are likely to be found.
The Hine’s emerald dragonfly, once thought to be extinct, also lives in groundwater-fed wetlands in or near these coastal fens. The dragonfly was added to the federal list of endangered species in 1995, and, in 2007, the U.S. Fish and Wildlife Service identified more than 14,000 acres of critical Hine’s emerald dragonfly habitat in Michigan, including locations in Alpena and Presque Isle counties.
Coastal fens can be explored on public lands at Rockport State Recreation Area in Alpena County and Thompson Harbor State Park in Presque Isle County. Rockport’s former use as an open-pit limestone quarry also serves as an example of the biggest threat to coastal fens.
“Many of these habitats have been degraded by mining,” Huffstutler said. “The fens that remain are special because they’re so rare, much like an endangered species. Because certain plants and insects are so specialized for these landscapes, it also means those plants are also rare, threatened or endangered and need to be protected.”
Individuals can help preserve these places and their plants and wildlife by doing the following:
∫ Keep vehicles on roads and marked trails
∫ Avoid stepping on plants or collecting wildflowers
∫ Clean boots and clothing before and after each outing to avoid transporting invasive plant seeds
∫ Report illegal or destructive activity to the Michigan Department of Natural Resources’ Report All Poaching hotline, 800-292-7800
Have fun, go explore and watch your step — especially if you’re a tasty insect.
Chris Engle is communications associate for Huron Pines, a 501(c)(3) nonprofit organization based in Gaylord and Alpena to conserve and enhance Northern Michigan’s natural resources to ensure healthy water, protected places and vibrant communities.