Coastal Submergence and Marsh Fringe Erosion

Abstract

Coastal wetlands may shrink, expand, or remain constant in area during coastal submergence, depending on sedimentation rates on the wetland surface in comparison with rates of submergence. Losses of coastal wetlands are primarily reflected in shoreline recession due to erosion and drowning. In Delaware Bay sea level rise, subsidence, and dissection are combining to produce rapid shoreline erosion and a net loss of wetIands as the coast is submerged. In Pamlico Sound, erosion rates are less severe, but still sufficient to cause a net loss of wetland area Along the Atlantic and Gulf coastal plain, marsh shoreline erosion rates of more than about 0.3 m/yr (and perhaps much less) will result in a loss of wetlands at a greater rate than new marshes can be created.