What is a “marsh dieback” and why is it called a “brown marsh”? What is the cause of the dieback? What area is affected? If marshes sometimes dieback naturally, why is this dieback different? What are some of the possible outcomes? What is being done? more questions...

Executive Summary (PDF 6.44 MB)

Dieback of Large Expanses of Salt Marsh Grass in Coastal Louisiana

New Article Series
The browning and dieback of over 100,000 acres of smooth cordgrass (Spartina alterniflora) served as a dire call to action for Louisiana's coastal science community. This 6-part series explores the response to that call, from satellite imagery to laboratory studies of individual plants.

Background
Spartina alterniflora, also known as smooth cordgrass or oyster grass, dominates regularly flooded saline marshes along the Gulf of Mexico and the eastern United States coastline. This highly productive ecosystem provides critical habitat and nutrition for many avian, fish, and invertebrate species. In the spring of 2000, fishermen and scientists noticed that certain areas of coastal marsh in south Louisiana were turning brown. While patchy areas of dieback have been noticed in the past, the size of the current dieback area is unprecedented. The areas most affected are the salt marshes between the Mississippi and Atchafalaya Rivers. 

Since the initial site visits in the early summer, the area of the marsh dieback has increased, and little recovery has been noted in affected areas. Inspections of

Brown Marsh Fact Sheets Brown Marsh Photos

roots  and rhizomes indicate that this event is not simply a dieback of aboveground plant material but can also result in death of belowground portions of the grass.

Brown Marsh Action
Although we currently do not know the cause of the marsh dieback, scientists believe it is related to a combination of stressors such as prolonged drought conditions and other unknown biological or environmental factors.

Dead and dying marsh as seen from an airplane. Dark green areas in the back are healthy black mangroves.

A working group of resource managers and scientists has been established to address the problem of the marsh dieback. Field sites have been set up to test an array of biological, chemical, soil, and water parameters; satellite and aerial imagery is being acquired; and the Governor’s Office is coordinating ongoing state and academic research efforts with federal efforts involving the CWPPRA Task Force and other coastal agencies and organizations.


Brown Marsh Response Effort
Congress has allocated approximately three million dollars for brown marsh research through the National Oceanic & Atmospheric Administration to the Louisiana Department of Natural Resources (LDNR). The Scientific-Technical Committee of the Barataria-Terrebonne National Estuary Program and LDNR awarded funding for tasks in five categories. Research projects began in April 2001 and will conclude in the fall of 2002. Researchers will submit quarterly progress reports to document data collection efforts. Aerial and ground surveys of brown marsh areas have been conducted, and additional reports are expected in August/September 2001.