AgBioResearch

MABR scientists have developed a pioneering, comprehensive approach that makes conserving and managing freshwater lakes, streams and wetlands more integrated and effective.

"We call our approach landscape limnology," explained Patricia Soranno, MABR fisheries and wildlife scientist. "It's a new way to study fresh water that considers all fresh waters together -- lakes, rivers and wetlands -- as they interact with one another and with natural and human landscapes. Our goal is to improve our broad understanding of the diversity of freshwater resources and to give freshwater managers science-based tools to manage and protect these bodies of water."

The research was published in the June 1 issue of the journal BioScience.

Michigan has more than 10,000 freshwater lakes larger than 5 acres, 30,000 miles of streams and more than 10,000 square miles of wetlands. State agencies -- mainly the Department of Natural Resources and Environment (DNRE) -- are charged with the enormous task of managing these freshwater resources to make sure all needs are met, including overseeing fish stocking and fishing regulations, applying herbicides to control aquatic plants, and setting withdrawal regulations and nutrient standards. But with limited budgets, data can be collected on only a small percentage of these aquatic resources.

Landscape limnology uses geographical information systems (GIS) data from satellites and aerial photos, including information on land use, soils and geology around the freshwater resources. This information is combined with data collected in the field, such as fish population numbers or nutrient levels in the water, to create models that decision makers can use to decide on the best management and conservation strategies to meet their goals.

Landscape limnology differs from traditional limnology by looking at freshwater resources as an integrated part of a complex landscape of terrestrial and aquatic elements rather than considering each lake or wetland as a single, isolated entity.

Soranno and MSU co-authors Mary Bremigan, MABR fisheries and wildlife scientist, and Kendra Spence Cheruvelil, assistant professor of fisheries and wildlife, said many current and emerging environmental issues have causes that range in scale from local to global. All three are members of the MSU Landscape Limnology Research Group. Land use change, exotic species invasions and climate change are all complex issues linked in ways that can be understood only by taking an approach that includes all these scales as well as freshwater, terrestrial and human landscape information. The Asian carp invasion, for example, may be linked to an increase in water temperature associated with climate change, the interconnectivity of inland lakes and streams, and the type of development happening along the shoreline.

"A landscape approach that considers what's happening at both the local water-body scale and at the broader regional scale is really the only way to study these types of issues," Cheruvelil said. "If you look at only one ecosystem in isolation, you don't see the whole picture."

"The landscape limnology framework makes it easy to run several complementary models at the same time," Bremigan added. "Right now, the people who manage fish use one model, and the people who manage nutrient levels use a completely different model, and they're rarely compatible, so it can be difficult to see how changes in one affect the other. Landscape limnology models make it easier to see the relationships among all the variables."

The DNRE began using the MSU scientists' landscape limnology approach in 2006 to set and manage nutrient levels in the state's freshwater lakes and streams, and the managers are very pleased with the results.

"The state of Michigan had to present our approach to U.S. Environmental Protection Agency [EPA] officials, and they gave us a very favorable review," Soranno said. "Now we're starting to work with agencies outside Michigan."

Other paper co-authors are Katherine Webster, of the School of Biological Sciences at Queen's University in Belfast; Tyler Wagner, of the Pennsylvania Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, at Pennsylvania State University; and Craig Snow, of the Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Association.

The research is supported by the EPA Office of Wetlands, Oceans and Watershed National Lakes Assessment Planning Project. The research of Soranno and Bremigan also is supported by Michigan AgBioResearch.