The area is identified by thick sections of unconsolidated sediments that are undergoing dewatering and compaction which contributes to high subsidence.
The fertile lands are used predominantly for agriculture, with sugarcane and pastures on the ridges, and forested wetlands in the lower elevations, leading to freshwater and saltwater marshes in the coastal areas, before opening up to Terrebonne and Timbalier Bays.
Isle de Jean Charles, home of the state-recognized tribe of the Isle de Jean Charles Band of Biloxi-Chitimacha-Choctaw Indians, was once 22,000 acres (8,900 ha) but has lost 98% of its land (down to 320 acres) to subsidence, saltwater intrusion natural disasters, climate change and oil/gas exploration.
[6] In 1907 Theodore Roosevelt, an avid birder saw the importance of protecting East Timbalier Island as a bird sanctuary.
President Roosevelt signed executive orders designating Breton Island, Tern, and Shell Keys — federally protected bird sanctuaries.
East Timbalier Island, as a coastal barrier and first line of defense against hurricanes and storm surges, is important.
There are over 700 wellheads around Terrebonne and Timbalier bays that were not designed or built to withstand the loss of the barrier island.
The Barataria-Terrebonne Estuary System (BTES) is an ecosystem of 4.1 million acres covering sixteen parishes in Louisiana.