Maud Walsh, Swoope, Elizabeth A. | 3/26/2008 8:52:00 PM
Louisiana’s coastal wetlands play a vital role in the economy of both Louisiana and the United States because they support almost a third of the United States’ crude oil production and a large portion of the nation’s coastal fisheries. Louisiana’s wetlands are also vital because they host large populations of migratory birds and buffer the impact of hurricanes and storm surges.
Although Louisiana has less than one-third of the continental United States’ wetlands, essentially all (90%) of the wetlands lost over the past 200 years have been in Louisiana. Wetland loss in Louisiana generally converts vegetated wetlands into open water. The land loss that occurs threatens roads, oil and gas pipelines, and regional infrastructure, which negatively impact national and state economies.
In Louisiana there are many causes of wetland loss. One cause of wetland loss is the compaction of wetland soils (also referred to as subsidence). A second cause is the reduced amount of sediment that is distributed into the wetlands as a result of levees built along the Mississippi River. A third cause is the rising sea level. And a final cause is from erosion caused by hurricanes and storm surges. Current estimates predict that Louisiana will lose more than 800,000 acres of wetlands and the shore will advance inland as far as 30 miles in places if no action to reduce wetland loss is taken.
A tremendous amount of research has been conducted to help minimize the rate of wetland loss in Louisiana. Comparisons between different types of restoration and management projects have been made. The results of these comparisons have shown that engineered structures, such as sea walls, breakwaters and groins, are not as effective as plants for restoring or managing wetland loss. This is because plants more effectively reduce erosion by minimizing floodwater velocity, trapping sediment and building organic soils.