Two ships in the United States Navy have been named the USS Breton after this area.
On August 29, 2005, Hurricane Katrina crossed the sound before making its third landfall near Pearlington, Mississippi.
The Breton Sound Basin is the remnant of a Mississippi River delta lobe, the abandoned St. Bernard Delta. The principal hydrologic features of the Breton Sound Basin include the Mississippi River and its natural levee ridges; the flood protection levee; the MRGO south disposal bank; Bayou Terre aux Boeufs and River aux Chenes (abandoned delta distributaries); and the freshwater diversions at Caernarvon, White's Ditch, Bohemia, and Bayou Lamoque.
The natural processes of subsidence, saltwater intrusion, and erosion of wetlands, and the human effects of river levee construction and the oil and gas industry, have caused major impacts to the Breton Sound Basin in recent decades. The two major wetland problems resulting from the natural processes and human intervention in this basin are sediment deprivation and saltwater intrusion.
Historically, the basin was flushed with large quantities of fresh water and sediments annually during the spring. Marine waters would then rise and enter the basin during the late summer and early fall months and would be flushed out the following spring. In the early 1930's, flood protection levees were raised along the Mississippi River as far south as Bohemia in the Breton Sound Basin. This prevented the annual input of fresh water, nutrients, and sediment that nourished the wetlands and combatted saltwater intrusion.