
Prairie pothole wetlands in central North America. Credit: Ducks Unlimited. Taken from the National Science Foundation website.
Wetlands come in all shapes and sizes, and one form is the “geographically isolated wetland,” or GIW. Often, GIWs occur in complexes that reach across broad expanses, such as the prairie potholes shown here, which span the central plains of North America. Vernal pools in California, cypress domes in Florida, and pocosins in the Carolinas also occur as vast numbers of small basins scattered across broad landscapes. Wetlands perform many valuable services, such as filtering sediment and pollutants, and thereby protecting lakes, rivers, and bays situated further downhill. But recently, GIWs have come under attack based on the assumption that because they are “isolated,” they do not provide these valuable services. This attack has been so sweeping that the US Supreme Court recently stripped GIWs of many protections, ruling that they don’t fall within the scope of the Clean Water Act. The Lewis Lab participated in a review article, led by John Marton of Indiana University, emphasizing that GIWs are anything but isolated, as they communicate with their surroundings through the movements of organisms and flows of nutrients and groundwater. Our article discovered that GIWs indeed provide services that should place them within the scope of the Clean Water Act. Read it here.