Carolina Environmental Diversity Explorations
Evidence of rising sea level · By Dirk Frankenberg
Subtidal seafloor
Figure 8. This marsh is being eroded by rising sea level. (Photograph by the author. More about the photograph)
Salt marshes do well in irregularly flooded areas, but rising sea level continuously converts these areas into regularly flooded habitats and then into a new seafloor. Some marsh plants, especially smooth cordgrass, can tolerate the first of these conversions, but none of them can survive the second.
Recently eroded marsh soils and the new subtidal seafloor that it forms are seen in Figure 8. Note particularly the muddy cliff that lies between the surface of the water and the marsh. This cliff, like those behind the beaches on the barrier islands, are telltale signs of recent erosion. If the erosion had taken place some time in the past, the cliff would have been converted to a slope. The fact that it has not been is evidence that erosion, the main architect of cliffs in sedimentary settings, has been at work quite recently.
If you are ever in the market for waterfront property, avoid lots with cliffed shorelines! In that direction lies continuously shrinking lot size or expensive and unsightly protection structures.
