But the Gulf is still filled with oil, and the reeds in the Louisiana marshes look like bristles of very dirty paintbrushes.

In the late 2000s NASAs Stennis Space Center, in partnership with the US Army Corps of Engineers New Orleans District and Tulane University, undertook an archaeological survey of the southeastern Louisiana marshes including the Bayou Grande Cheniere site.

Almost every fish caught in the Gulf of Mexico spends part of its life in the Louisiana marsh.

They may sprawl over four million acres, like the Louisiana marshes and swamplands that constitute 40 percent of the nation's total coastal wetlands.

They support one of the country's largest fisheries; almost every fish caught in the Gulf of Mexico spends part of its life in the Louisiana marsh.

Louisiana marshes are a nursery for many fish caught in the gulf, and they support the state's rich Cajun culture.

IN flights over the Louisiana marshes, Dave Hall, a Federal fish and wildlife agent as familiar with the territory as with his own backyard, now becomes disoriented, he says, "because it's changing so quickly."

While nutria are the most common herbivores in Louisiana marshes, they are not the only ones.

A pirogue is a small, flat-bottomed boat of a design associated particularly with the Cajuns of the Louisiana marsh.