Sea-Level Rise, Subsidence, and Wetland Loss

This video describes causes of wetland loss in the Mississippi River Delta. Rapid land subsidence due to sediment compaction and dewatering increases the rate of submergence in this deltaic system.  The construction of levees along the lower Mississippi River also has reduced delivery of sediments to coastal wetlands, which have been deteriorating as soil surfaces sink and wetland plants are subjected to excessive flooding.  Other factors that have contributed to land loss include construction of canals and periodic hurricanes.

This video describes research being conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partner, Dr. Julia Cherry. Their goal is to better understand the effects of sea-level rise and other global change factors on coastal wetlands in the Mississippi River Delta. This region contains over 40% of the U.S. wetlands in the lower 48 states. These wetlands support commercial fisheries, provide habitat for waterfowl and wildlife, and act as storm buffers, protecting several important ports and cities such as New Orleans.

This video describes an investigation to determine how much storm sediment from Hurricane Gustav (2008) was deposited in marsh and mangrove stands and if these different types of vegetation influence sediment capture. McKee and colleagues carried out their research by helicopter, which is the only way to sample the vast wetlands in coastal Louisiana. The results of their investigation will lead to a better understanding of how hurricanes may benefit coastal wetlands.

The video highlights the East Marsh Island Marsh Creation project (TV-21) while sharing basic information about using sediment in re-establishing and re-creating healthy wetland ecosystems. Through the use of sediments and hydrology new marsh is being created where standing water once was. CWPPRA project managers and scientists explain and demonstrate the process of the rebirth of this once lost marsh.