Goal: At least 80% of the shoreline is natural

The Coastal Assembly will track progress towards this goal by collecting data for the following metric:

  • Percent natural (or softened) shoreline

Great Lakes coastal wetlands are most sustainable when they are supported by a natural shoreline, shorelines in their original state or bioengineered to minimize negative impacts on wetland habitat.

The Assembly envisions coastal landscapes that support the unique structure and processes essential for sustaining healthy species populations, resilient natural communities, and for providing benefits to human society. In its  focus on coastal wetlands, the Assembly has stated a goal that “Natural shoreline is at acceptable levels.” Tracking progress towards this goal requires us to monitor the state of shorelines across the Great Lakes basin.

  • Percent natural (or softened) shoreline

Natural shoreline provides habitat for aquatic-dependent life, maintains water quality, and preserves natural coastal wetland processes. Hardening shorelines to protect them against erosion using artificial structures, such as concrete rubble or sheet piling, can inhibit the above-mentioned benefits.

Percentage of natural shoreline is an important indicator of coastal wetland health. The softening of hardened shorelines and the creation of bioengineered shorelines have helped bring back coastal wetland habitat that supports biodiverse aquatic and terrestrial plant and animal life.

There is no current, basin-wide shoreline classification data set, and comparable shoreline data from two time periods is only available for Lake Ontario. NOAA published a comprehensive shoreline classification and data set in 1997 (updated in 2000), and Environment Canada completed a similar effort for Canada between 1987 and the late 1990’s. 

These data sets together formed a baseline to which all subsequent State of the Great Lakes reports have referred; there have been no basin-wide updates in status. In 2018, NOAA published a statement of work to acquire an updated shoreline hardening data set for the US Great Lakes shoreline.

Data were provided by the Great Lakes Aquatic Habitat Framework (GLAHF). These other resources were surveyed for classification systems, term descriptions, target values and goals, and current statuses:

A Revised Geomorphic, Shore Protection and Nearshore Classification of the Canadian and United States Shorelines of Lake Ontario and the St. Lawrence River (Stewart 2002)

State of the Great Lakes Technical Report (2017)

Historical Loss and Current Rehabilitation of Shoreline Habitat along an Urban-Industrial River—Detroit River, Michigan, USA (Hartig 2017)

Great Lakes Biodiversity Conservation Strategies (2009-2015)

USACE Shoreline Classification (2012)

NOAA/GLERL Great Lakes and St. Lawrence River Medium Resolution Vector Shoreline Data (1998)

Great Lakes Environmental Assessment and Mapping Project (GLEAM)

The Great Lakes Aquatic Habitat Framework (GLAHF) data set was last updated in 2012, through a compilation of data from the National Oceanic and Atmospheric Administration (NOAA), Environment Canada (EC)*, and the U.S. Army Corps of Engineers (ACOE).

*Now known as: Environment and Climate Change Canada

A percent natural value was calculated using 1 km shoreline segments provided and classified into natural vs hardened by the Great Lakes Aquatic Habitat Framework (GLAHF) for lake, state/province, lake sub-basin, and county units.