A review of selected ecosystem services provided by coastal wetlands of the Laurentian Great Lakes.

Significant ecosystem services derive from the coastal wetlands of the Laurentian Great Lakes even though two-thirds of the original coastal wetlands have been lost since European settlement, and the remaining 126,000 ha of U.S. coastal wetlands and >=70,000 ha of Canadian wetlands are affected by anthropogenic stressors. Published information indicates that wildlife habitat, fisheries support, and water quality improvement are significant ecosystem services provided by Great Lakes coastal wetlands that should be strongly considered during management decision making. 30 species of waterfowl, 155 breeding bird species, and 55 species of reptiles and amphibians are supported by coastal wetland habitats across the Basin. Nearly all sport and commercial Great Lakes fish species use coastal wetlands for life-cycle functions, and Great Lakes food webs are supported by wetland export of young sport and forage fish. Biological responses indicate declines in the wildlife and fishery services with increasing levels of anthropogenic disturbance. Extrapolation from a single well-studied system suggests that, Basin-wide, coastal wetlands may retain nearly 4000 tonnes P and 53,000 tonnes N per year, but additional studies are needed to support these estimates and determine stressor effects. Coastal wetlands appear to retain sediments over long time scales, but may either retain or release sediments during storm events. Extrapolation of carbon sequestration from other wetland types suggests that less than 90 g C yr-1 might be retained across the Basin. Wild rice production provides a culturally important ecosystem service, and coastal protection may be locally significant where fringing wetland remain. To support management decisions, quantitative relationships between specific stressors or land use practices and the delivery of ecosystem services are needed, as are ecosystem service indicators to measure those responses.