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Coastal wetlands of Lake Superior’s south shore
Citation:
Brazner, J. AND A. Trebitz. Coastal wetlands of Lake Superior’s south shore. Chapter 21, Finlayson, C.M., Milton, R., Prentice, C., Davidson (ed.), Wetlands of the World, Springer Reference Encyclopedia of Wetlands. Springer Netherlands, , Netherlands, , 1-15, (2017).
Impact/Purpose:
This chapter, in an on-line reference text called “The Wetland Book”, gives a non-technical overview of Lake Superior’s coastal wetlands. Information reviewed includes the typical geomorphic setting of the wetlands, their general ecology including species and ecosystem types supported, and the factors that threatened wetland extent, quantity, and quality. The chapter does not include research data, but does provide an entry point to the coastal wetland literature, as well as a map and inventory of coastal wetlands along Lake Superior’s U.S. shoreline and photographs illustrating the major wetland types.
Description:
There are more than two thousand coastal wetlands that encompass an area of about 215,000 ha in the Laurentian Great Lakes (LGL) of North America. Coastal wetlands in the LGL are distinguished hydrologically from nearby inland wetlands by a direct surface water connection with waters of an adjacent Great Lake. Daily, seasonal, annual and decadal lake level fluctuations exert important influences on the ecology of LGL coastal wetlands. Levels of human impacts in the LGL are generally greatest in the south, near the larger centers of population and most intense agriculture. Lake Superior is the largest (82,100 km2) and most northern of the LGL and coastal wetlands associated with Lake Superior are among the least disturbed by human influences. The distribution of coastal wetlands along the US shoreline of Lake Superior in Wisconsin and Michigan is skewed towards the southwestern end of the lake due to differential effects of isostatic adjustment following glaciation. The locations, geomorphic settings and basic characteristics of these south-shore wetlands are provided. Great Lakes coastal wetlands come in a variety of shapes and sizes. There is general agreement that there are three primary geomorphic types lacustrine, riverine and barrier-protected with riverine and barrier-protected being most common along the US shoreline of Lake Superior. Coastal wetlands in Lake Superior are the most peat-dominated and support some of the highest levels of biodiversity among all LGL habitats. Process-oriented work indicates that Lake Superior coastal wetlands, 1) can export considerable numbers of young fish to adjacent bays and nearshore food webs, 2) have unique habitat fingerprints manifest in fish biochemical signatures that can be used to quantify wetland-nearshore interactions, and 3) structure, function, and response to anthropogenic stressors are all strongly influenced by hydrogeomorphic setting. Shoreline and watershed development, invasive species and climate change are among the most challenging factors affecting the integrity of Lake Superior and other Great Lakes coastal wetlands.
