Testing the interdunal waters

Michigan's interdunal wetlands are places of great biodiversity, yet little scientific research exists about these rare habitats. Dr. Tiffany Schriever's Michigan Sea Grant-funded research aims to understand how aquatic communities found within the wetlands respond to environmental variation. She and her students measure food webs, as well as the identity and abundance of various reptile, amphibian and insect species, to examine their response to natural and human disturbances.

"Coastal wetlands provide essential ecosystem functions maintaining the health of the Great Lakes and offer critical habitat for aquatic biodiversity," says Schriever, assistant professor of biological sciences. "Yet many, if not all, interdunal wetlands are located in Department of Environmental Quality-recognized 'critical dunes areas."'

Formed within the low-lying spaces between dunes along the Great Lakes and especially prevalent along the eastern Lake Michigan coastline, the interdunal wetlands come and go based on lake water levels. Due to their natural rarity and restricted range, impacts to these areas can be particularly devastating. According to the Michigan Natural Features Inventory, interdunal wetlands are classified as imperiled in the state.

"My work helps to understand the connection between dunes and coastal wetlands, and offers critical insight for the management and conservation of these imperiled habitats," Schriever says.

To conduct her research, Schriever and a team of graduate and undergraduate students spend the summer sampling the wetlands for insects, reptiles and amphibians, surveying the landscape for various species and taking water chemistry and habitat measurements. "Fieldwork is the most rewarding part of the job," Schriever says.

"We bring the insects that we've collected into the laboratory at WMU and identify them to species. We then use the data to assess whether changes in species' composition have occurred over time and at different spatial scales."

Schriever emphasizes that there is still much to be learned from these critical habitats and she plans to continue research in this area for years to come. "My next steps are to determine the factors that regulate aquatic community assembly and use population genetics to determine spatial connectivity among the wetlands," she says. "I find it incredibly rewarding that we discover new things about how the wetlands function and what animals live in them all the time."

To learn more about WMU researchers' work in freshwater science and sustainability, view the 2018 issue of Arts and Sciences Magazine.