Lake Superior Coastal Zone

Splash pools, Devils Island, (Ashland County). Photograph, E.J. Judziewicz.

The Wisconsin shoreline of Lake Superior contains a diverse array of natural features. Among the most distinctive and noteworthy are the freshwater estuaries and sand spits that characterize the southwestern Lake Superior shoreline, the wave carved sandstone cliffs of the northern Bayfield Peninsula and Apostle Islands, and the floristically rich “red clay” wetlands that occupy ancient lacustrine deposits. Red clay wetlands are especially well developed near the City of Superior. Important wetland communities of the Lake Superior coastal region include marsh, fen, bog, sedge meadow, shrub swamp, lowland hardwood forest, and conifer swamp. Extensive beds of emergent, submergent, and floating-leaved aquatic plants occur in the shallower waters of the estuaries, partially protected from wind, wave and ice action by the sand spits situated at the mouths of streams entering the lake. The larger sand spits typically contain beach, dune, and pine forest communities, and where the dunes are active interdunal swales support unusual assemblages of wetland plants. The coastal wetland complexes receive heavy use by migratory birds, particularly in the spring. The larger coastal wetlands also host significant populations of nesting birds and spawning fish, as well as many resident herptiles and invertebrates. (For a fuller discussion of Wisconsin’s Lake Superior wetlands see Epstein 1997 and Epstein et al. 1997).