Response of Tidal Salt Marshes of the U.S. Atlantic and Gulf Coasts to Rising Sea Levels

Abstract

A salt marsh responds in many diverse ways to a rising sea level. A major factor is its ability to maintain surface elevations with respect to the mean high water level. Other influences include local submergence rates, sedimentation rates, density and composition of the indigenous flora and type and intensity of cultural modifications. If sea level rise accelerates, it would be reasonable to assume that further stresses will be placed on these systems, most likely resulting in increased losses. If the relative rate of sea level rise reaches catastrophic proportions (exceeding 10 mm yr‾ l ), substantial reductions in wetland area and a corresponding increase in open water habitats is projected. Due to the complex interrelationship of natural processes and cultural alterations that have previously influenced marshes it is difficult at the present time to separate and identify responses. Thus, each marsh must be assessed individually until we have a more thorough understanding of these systems in general.