The lowland areas of the Laurentian Great Lakes historically supported extensive coastal wetlands that provided habitat for many organisms (fish, birds, invertebrates, plants), supported ecosystem functions (nutrient transformation, plant diversity) and services (flood mitigation, water quality improvement), and provided aesthetic and recreational benefits to society. Since the late 1800s, most of these wetlands have been drained and converted to other uses. The U.S. side of western Lake Erie has lost an estimated 95% of its coastal wetlands, most of which are now active agricultural lands. The congressionally-supported Great Lakes Restoration Initiative recognized the need for coastal wetland restoration in 2010 and has supported extensive restoration efforts since. However, decision makers lacked fine-scale data to identify areas on the landscape with the right physical conditions and setting to support restoration back to coastal wetland status (i.e., wetlands hydrologically connected to the Great Lakes).
We met this need by conducting an assessment of areas that historically supported coastal wetlands along the Michigan and Ohio shore of Lake Erie. Publicly available data were used to conduct a geospatial analysis and form an ecological model for spatial prioritization. Data products were served through a new web-based mapper to support user-driven queries and exploration.
The assessment produced a restorability index layer that is being served to users through an online mapper (https://glcwra.wim.usgs.gov/). The western Lake Erie model analyzed 192,618 ha of U.S. shoreline and identified 2,538 ha of land assessed as highly restorable and additional 7,849 ha as slightly less suitable for restoration to coastal wetland habitat. The remaining area in the study boundary is unlikely to be restored because of impervious surfaces or hydrologic isolation from the lake. Many GLRI and other restoration activities are located in Lucas County, Ohio, but Ottawa County, Ohio, appears to have extensive restorable habitats for future consideration.
The algorithm in the restorability model can be adjusted to test alternative futures (e.g., weighting for more fish habitat), so outputs can be customized to meet user needs that vary by geography or restoration objective. This project supports Landscape Conservation Design and other planning efforts to identify and prioritize wetland restoration activities in the region. Land managers now have an additional resource to identify areas to consider for coastal wetland restoration and support landscape-scale planning.