Biology Instructor Dan Stinnett shows off isolated marsh near DCTC
One soggy May afternoon, Dan Stinnett, a biology instructor in the General Education department at Dakota County Technical College, waited for a break in the rain and took two members of the DCTC Institutional Advancement staff on a tour of a wetland area just south of the college’s main campus in Rosemount, Minn. Stinnett discovered the wetland after hearing amphibian calls coming from what he at first considered an unlikely location. He now uses the wetland as a teaching tool for his students.Institutional Advancement Director Erin Edlund and Grants and Sustainability Coordinator Chris Hayes spent an hour with Stinnett, memorizing frog and toad calls while learning how the roughly 9.3 million acres of wetlands remaining in Minnesota provide crucial benefitsto the state’s environment, including flood and erosion control, and groundwater recharging.
“Dan worked for 30 years as a field biologist and field supervisor for the U.S. Fish and Wildlife Service before he began teaching environmental science at DCTC,” Hayes said. “One of Dan’s areas of expertise is wetland management. He works as a volunteer for the Wetland Health Evaluation Program, or WHEP, in Dakota County. He collects scientific data for WHEP and teaches citizens how to protect and conserve wetland resources.”The wetland behind DCTC is a one-acre jewel framed by 100-foot pines and virtually hidden from surrounding farm and grasslands. On the day of the tour, the wetland’s water level was exceptionally high due to heavy spring rains, but Stinnett pointed out that all the water would be gone by summer’s end.
“During wintertime, this wetland is covered with snow and becomes a deer yard,” he said. “The deer just stay here and hang out because they are sheltered from the wind. Most people drive by this wetland and never suspect it’s here.”
As part of his job for WHEP, Stinnett sets bottle traps in area wetlands to capture invertebrates, which are not only a staple food source for birds and amphibians, but also serve as an accurate tool for measuring a wetland’s overall health.“Wetlands work like nature’s kidneys, cleansing pollutants and sediments from water that eventually flows into rivers and oceans,” he said. “But when we drain wetlands, we destroy those kidneys, allowing runoff containing nitrates and fertilizers to reach the Mississippi basin. We now have a dead zone in the Gulf of Mexico the size of New Jersey because those nitrates trigger an explosion of phytoplankton, or microscopic marine organisms. The phytoplanktonthen die and fall to the bottom, where their remains are consumed by bacteria, a process that uses up oxygen in the water.”
Besides acting as a water purifying system and watershed regulator, wetlands serve as natural habitats for countless fish and wildlife species. Wetlands like the one behind DCTC are home to a number of amphibians, including American toads, western chorus frogs, gray tree frogs, spring peepers and wood frogs. One reason for the tour was to give Edlund and Hayes, whom Stinnett equipped with hip waders and walking sticks, the opportunity to learn how to distinguish between different frog and toad calls.
“I’m not overly fond of toads,” said Edlund, who is an avid huntress and fisherwoman, but has been averse to toads of any ilk since childhood. “We didn’t actually see any toads today because they stay hidden in the water, but we did hear chorus frogs and American toads singing. They are incredibly loud.”“We did see a number of birds, including the American redstart and a pair of mallards,” added Hayes, who is keeping track of bird species that visit his property near Webster, Minn. At last count, he had spotted 64 different kinds of birds. Several—such as the great blue heron, green heron, great egret, wood duck and Canada goose— depend on wetlands for their survival.
“I know a few bird calls, but now I can add two amphibians to the list of wild creatures I can identify by sound,” Hayes said. “The same day we visited the wetland with Dan, I went home and heard American toads and chorus frogs singing like crazy in a very tiny wetland bordering our land. I’ve also started noticing dozens of American toads, some of them quite huge, living in our lawn, ponds and gardens—but don’t tell Erin.”
Links of Interest
- “Wise in the Ways of Water: In the field with Dan Stinnett”
- Minnesota DNR: Wetlands
- Minnesota DNR: Frog & toad opera
- Minnesota DNR: Reptiles/Amphibians of Minnesota
- Minnesota DNR: Sense of Place: Attuned to Frogs
- Wikipedia: List of birds of Minnesota
- Minnesota Birds
- DCTC General Education
Wetland Outing Gallery
For more info on wetland preservation or DCTC environmental science courses, contact:
- Dan Stinnett
Environmental Science Instructor