Mapping ecosystem service indicators in a Great Lakes estuarine Area of Concern

Estuaries provide multiple ecosystem services from which humans benefit. Twenty-seven Great Lakes coastal systems in the United States and Canada, many of them estuarine, are currently designated as Areas of Concern (AOCs) due to a legacy of chemical contamination, degraded habitat, and non-point-source pollution. The ecosystem benefits that current and future human communities can receive from these degraded ecosystems are diminished. For an AOC to be delisted, it is generally necessary to restore aquatic habitat, among other actions. Ecosystem service mapping and assessment can inform AOC restoration and management. We describe an approach, with examples, for assessing how local-scale actions affect the extent and distribution of coastal ecosystem services, using the estuarine portion of St. Louis River AOC of western Lake Superior as a case study. We applied mapping criteria derived from locally validated predictive models, published relationships, local experts, and other sources to spatially explicit biophysical data to map indicators of ecosystem services at high resolution across aquatic and riparian habitats. We mapped indicators for 23 biophysical services in the estuary (e.g., natural views, boating, game and non-game fish and wildlife species, wild rice, parks and trails, beaches, property protection, sacred sites). Most 10 × 10 m aquatic pixel locations had 3-7 overlapping services; riparian locations had fewer mapped services. To examine tradeoffs in services associated with management actions, we quantified the changes in the area of the AOC providing each ecosystem service for scenarios based on planned sediment remediation and habitat restoration projects. Some aspects of our approach can be adapted by Great Lakes coastal communities to support local environmental decision-making.