Changes occurring along a rapidly submerging coastal area: Louisiana, USA

Abstract

Within the last century the Louisiana coastline began an accelerated rate of retreat primarily due to rapid subsidence. Implications of changes occurring along the rapidly subsiding Louisiana coast could be of concern worldwide, because of similar situations that may be encountered in the future if the predicted global rise in sea level occurs. The lack of sediment deposition with respect to rapid coastal subsidence cause increased submergence which in turn causes numerous habitat changes. Various human (canal cutting, leveeing, dredging, etc.) and natural processes (hurricanes, tropical storms, etc.) conjunctively influence the rate of deterioration. Landward retreat of the wetlands, in addition to causing land loss, promotes secondary effects such as saltwater intrusion, aquifer contamination, loss of freshwater marshes and disappearance of the present biota. Flooding will cause increases in salinity, waterlogging, and anaerobiosis, killing native vegetation and eventually resulting in open bodies of water.