Techniques for restoration of disturbed coastal wetlands of the Great Lakes

A long history of human-induced degradation of Great Lakes wetlands has mad e restoration a necessity, but the practice of wetland restoration is relat ively new, especially in large lake systems. Therefore, we compiled tested methods and developed additional potential methods based on scientific unde rstanding of Great Lakes wetland ecosystems to provide an overview of appro aches for restoration. We addressed this challenge by focusing on four gene ral fields of science: hydrology, sedimentology, chemistry, and biology. Hy drologic remediation methods include restoring hydrologic connections betwe en diked and hydrologically altered wetlands and the lakes, restoring water tables lowered by ditching, and restoring natural variation in lake levels of regulated lakes Superior and Ontario. Sedimentological remediation meth ods include management of sediment input from uplands, removal or proper ma nagement of dams on tributary rivers, and restoration of protective barrier beaches and sand spits. Chemical remediation methods include reducing or e liminating inputs of contaminants from point and non-point sources, natural sediment remediation by biodegradation and chemical degradation, and activ e sediment remediation by removal or by in situ treatment. Biological remed iation methods include control of non-target organisms, enhancing populatio ns of target organisms, and enhancing habitat for target organisms. Some of these methods were used in three major restoration projects (Metzger Marsh on Lake Erie and Cootes Paradise and Oshawa Second Marsh on Lake Ontario), which are described as case studies to show practical applications of wetl and restoration in the Great Lakes. Successful restoration techniques that do not require continued manipulation must be founded in the basic tenets o f ecology and should mimic natural processes. Success is demonstrated by th e sustainability, productivity, nutrient-retention ability, invasibility, a nd biotic interactions within a restored wetland.