The Mississippi coastline is 113 linear kilometers (70 miles) long and its estuaries cover approximately 594 km (369 mi; Figure 1) (Handley and others, 2007). It has a man-made sand beach 43.5 km (27 mi) long and 595.5 km (370 mi) of shoreline (Klein and others, b., 1998). The Mississippi Sound extends across the coastal waters of the State and encompasses 175,412 ha (433,443 acres). It is bordered by the Mississippi coast; Mobile Bay, Ala.; the Gulf Islands National Seashore barrier islands; and Lake Borgne, La. The watersheds and drainages feeding into Mississippi Sound, excluding tidal exchange from the Gulf of Mexico, include Lake Borgne, Pearl River, Jourdan River, Wolf River, Biloxi River, Tchoutacabouffa River, Pascagoula River, and Mobile Bay. The Pascagoula River is one of the last undammed rivers in the continental U.S. and the only undammed river flowing into the Gulf of Mexico. Freshwater inflow into Mississippi Sound, excluding that from Mobile Bay, averages 882.4 m³ per second (30,806 ft³ per second).

The Mississippi coastal zone contains approximately one-third of the State’s 120 ecological communities (Klein and others, a., 1998). Regional land use includes silviculture, agriculture, and urban development, including several coastal casinos. Commercial shipping, shipbuilding, phosphate rock refinement, and electric power generation companies include some of the industrial complexes found along the Mississippi coast. The three counties found along the Mississippi coast, Hancock, Harrison, and Jackson Counties, had a total population of 370,702 as of 2010, constituting 12.5 percent of the State’s population (U.S. Census Bureau, 2010). These counties cover over 160.9 km (100 mi) of coastline and are one of the fastest growing regions in the state (Klein and others, b., 1998).

The casino industry, military installations, trade, and manufacturing provide most jobs in coastal Mississippi. Two major deep-water ports exist in coastal Mississippi. Recreation and tourism have a significant impact on Mississippi’s economy as well, annually attracting approximately 1.8 million visitors to the coast and generating approximately \$3.5 billion statewide, about one-third of which comes from coastal tourism. Ninety percent of the coastal tourism expenditures come from recreational boating and related industries. Marine recreational fishing generates more than \$50 million annually, with approximately 280,000 participants, more than a million recreational fishing expeditions, and over 40,000 resident saltwater sportfishing licenses sold each year. More than one-fourth of the anglers fishing in coastal Mississippi are tourists. Landings of shrimp, crabs, oysters, and finfish equal approximately 99.8 million kg (220 million lbs) of seafood annually. The entire seafood industry in coastal Mississippi, including processing of seafood caught in other Gulf States, generates approximately \$450 million per year.