Yes, it is not unusual for salt marshes to experience dieback in small patches in some years. However, these areas are usually less than an acre or so in size and generally regenerate the next year or over the next several years.
The phenomenon of brown marsh has been observed along Louisiana's coastline. Hardest hit is the Barataria-Terrebonne estuary extending from the west side of the Mississippi River to the Atchafalaya River.
Effects to industries such as oil and gas cannot be predicted, but healthy marshes and barrier islands are known to be important storm buffers to Louisiana's mainland.
Wetlands are transitional areas, sandwiched between permanently flooded deepwater environments and well-drained uplands,  here the water table is usually at or near the surface or the land is covered by shallow water.
The coastal prairie, located along the coastal plain of southwestern Louisiana and southcentral Texas, is the southernmost tip of the tallgrass prairie ecosystem so prevalent in the Midwest.
Brown Marsh is a term that scientists have given to the unusually extensive and rapidly spreading browning of Louisiana’s normally lush green intertidal saltwater marsh grass Spartina alterniflora, known more commonly as oyster grass or smooth
Wetlands have come under natural and human threats (from subsiding or sinking land to draining or filling for new development). Scientists estimate that the lower 48 United States have lost more than half of their wetlands since colonial times.
Wetlands offer many significant benefits for fish and wildlife as well as society. They provide habitat for thousands of species of aquatic and terrestrial plants and animals.
The USGS National Wetlands Research Center conducts wetlands research for use by resource managers, policy makers, and the public. Considerable information is available on their Web site.