The Breton Wilderness, according to the Clean Air Act, is listed as a Class I Prevention of Significant Deterioration Area.

Large areas of beach and marsh were destroyed and much of the vegetation that stabilizes the islands and provides habitat for the pelicans and other animals was uprooted or damaged.

They are also monitoring the brown pelicans and other birds that return to nest on the islands and nearby, less desirable habitat to determine the long-term impact on this endangered species.

The barrier islands that make up Breton NWR are remnants of the Mississippi River's former St. Bernard Delta, which was active about 2,000 years ago.

These barrier islands are dynamic; their sizes and shapes constantly are altered by tropical storms, wind, and tidal action.

Early literature on Breton and the Chandeleur Islands mentions trees and a generally higher elevation than exists today.

Breton NWR provides habitat for colonies of nesting wading birds and seabirds, as well as wintering shorebirds and waterfowl.

Waterfowl winter near the refuge islands and use the adjacent shallows, marshes, and sounds for feeding and for protection during inclement weather.

The dominant vegetation on Breton NWR are black mangrove (Avicennia germinans), groundsel bush (Baccharis halimifolia), and wax myrtle (Myrica cerifera).