The Coastal Crisis and Louisiana's Response

From the cypress and tupelo swamps in the west to the vulnerable Chandeleur Islands in the east, the fragile wetlands of Region One act to preserve, protect and nurture the wildlife and culture of this unique area. After 300 years of urban development, this region has the least amount of wetland left of any of the Louisiana coastal regions. Nevertheless, it stands to lose an additional 45,000 acres of marsh and over 100,000 acres of swamp by 2050 if nothing is done to restore the wetlands surrounding the Gulf's largest and most vulnerable estuary.

These valuable marshes and swamps are deteriorating, and at least some of the causes are clear:

Natural subsidence of this ancient part of the Mississippi delta
Sea level rise
Lack of fresh water, nutrient and sediment input from the leveed Mississippi River
Salinity increases
Large populations of nutria and muskrat
Hurricane damage (hurricanes Betsy, Camille, Andrew and Georges, in particular)
Lakeshore erosion
Draining, ponding and canal building

Louisiana Department of Wildlife and Fisheries

The marshes and swamps on the land bridges between the large lakes are particularly important because they protect the upper parts of the estuary from the direct influence of the Gulf. Should they be breached or destroyed, the tidal flux, wave energies and saltwater intrusion into the western end of the region would be devastating. The fringe marshes act as nursery grounds for many forms of wildlife, including commercial and recreational marine species such as redfish, speckled trout, shrimp and blue crab. They also serve to soak up storm waters and filter out pollutants before they can reach the lakes.

If the wetlands are destroyed, New Orleans, squeezed between the leveed shores of Lake Pontchartrain and the levees of the Mississippi River, could lose much more than important species of fish. The petrochemical industries, the seaport, the cultural center and almost two million people are all at risk.

Louisiana Office of Tourism Photo

The Mississippi River Gulf Outlet (MRGO) navigational channel, opened in 1963, has provided a forewarning of the sort of disaster that wetlands loss can engender. By breaching La Loutre Ridge, this channel brought salt water from Breton Sound to East New Orleans, increased the salinity of Lake Pontchartrain and caused a large lake-bottom "dead zone" at its outlet. The erosion along its banks from the wave energy of passing ships and the destruction of adjacent freshwater marsh has caused the MRGO channel to widen from 750 feet to more than 2,000 feet in some areas.

Wetlands restoration within Region One requires the coordinated efforts of many concerned groups. A problem in any one area can have rapid consequences elsewhere in the estuary complex as the waters in the lakes can circulate brackish water along their shores and into the marshes and swamps. Like falling dominoes, the disappearance of the Biloxi Marshes would threaten the Pontchartrain / Borgne land bridge and eventually the Maurepas / Pontchartrain land bridge as well.

MRGO
US Army Corps of Engineers

But something is being done to hold these fragile pieces of the ecosystem in place. Even though the Chandeleur Islands are a designated wilderness area (where human alterations are usually prohibited), oyster grass (Spartina alterniflora) is being planted to alleviate some of the damage Hurricane Georges caused in 1998. Some marshes surrounding the rest of the estuarine lakes are being restored by pumping out excess water or by rebuilding fragmented marsh and shallow open-water areas with dredged sediments. A diversion from the Mississippi River is planned for the large swamp southwest of Lake Maurepas, bringing fresh water, nutrients and sediment.

To keep the lakes healthy, bottom shell dredging is now prohibited and successful efforts are underway to control the pollution sources of the shores. Some of the most vulnerable parts of the shorelines have (or will soon have) rock breakwaters to diminish the wave energy eating away at the marshes. In total, half a dozen restoration projects have reclaimed nearly 5,000 acres of wetland and six developing projects are projected to rescue 1,100 more acres.