Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers, with islands periodically separated by tidal inlets. The largest barrier island in the world is Padre Island of Texas, United States, at 113 miles (182 km) long. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula, often including a beach, barrier beach. Though many are long and narrow, the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.
Perdido Key State Park is a 247-acre (1.00 km2) Florida State Park located on a barrier island fifteen miles (24 km) southwest of Pensacola, off S.R. 292, in northwestern Florida. The address is 12301 Gulf Beach Highway.
Assateague Island is a 37-mile (60 km) long barrier island located off the eastern coast of the Delmarva Peninsula facing the Atlantic Ocean. The northern two-thirds of the island is in Maryland, and the southern third is in Virginia.
Laguna de Términos is the largest tidal lagoon by volume located entirely on the Gulf of Mexico, as well as one of the most biodiverse. Exchanging water with several rivers and lagoons, the Laguna is part of the most important hydrographic river basin in Mexico. It is important commercially, as well as ecologically by serving as a refuge for extensive flora and fauna; its mangroves play an important role as a refuge for migratory birds.
Gulf Islands National Seashore is an American National seashore that offers recreation opportunities and preserves natural and historic resources along the Gulf of Mexico barrier islands of Florida and Mississippi. In 2023, it was the fifth-most visited unit of the National Park Service.
Padre Island is the largest of the Texas barrier islands and the world's longest barrier island. The island is located along Texas's southern coast of the Gulf of Mexico and is noted for its white sandy beaches. Meaning father in Spanish, it was named after Father José Nicolás Ballí (c.1770-1829), who owned the island and served as a missionary priest and collector of finances for all the churches in the Rio Grande Valley. He also founded the first mission in present-day Cameron County.
Horn Island is a long, thin barrier island off the Gulf Coast of Mississippi, south of Ocean Springs. It is one of the Mississippi–Alabama barrier islands and part of the Gulf Islands National Seashore. Horn Island is several miles long, but less than a mile wide at its widest point. It occupies about 4.2 square miles (11 km2).
Assateague Island National Seashore is a unit of the National Park Service system of the U.S. Department of the Interior. Located on the East Coast along the Atlantic Ocean in Maryland and Virginia, Assateague Island is the largest natural barrier island ecosystem in the Middle Atlantic states region that remains predominantly unaffected by human development. Located within a three-hour drive to the east and south of Richmond, Washington, Baltimore, Wilmington, Philadelphia major metropolitan areas plus north of the several clustered smaller cities around Hampton Roads harbor of Virginia with Newport News, Hampton, Norfolk, Portsmouth, Chesapeake and Virginia Beach. The National Seashore offers a setting in which to experience a dynamic barrier island and to pursue a multitude of recreational opportunities. The stated mission of the park is to preserve and protect “unique coastal resources and the natural ecosystem conditions and processes upon which they depend, provide high-quality resource-based recreational opportunities compatible with resource protection and educate the public as to the values and significance of the area”.
The Western Gulf coastal grasslands are a subtropical grassland ecoregion of the southern United States and northeastern Mexico. It is known in Louisiana as the "Cajun Prairie", Texas as "Coastal Prairie," and as the Tamaulipan pastizal in Mexico.
Perdido Key is an unincorporated community in Escambia County, Florida located between Pensacola, Florida and Orange Beach, Alabama. The community is located on and named for Perdido Key, a barrier island in northwest Florida and southeast Alabama. "Perdido" means "lost" in the Spanish and Portuguese languages. The Florida district of the Gulf Islands National Seashore includes the east end of the island, as well as other Florida islands. No more than a few hundred yards wide in most places, Perdido Key stretches some 16 miles (26 km) from near Pensacola to Perdido Pass Bridge near Orange Beach.
Mustang Island is a barrier island on the Gulf Coast of Texas in the United States. The island is 18 miles (29 km) long, stretching from Corpus Christi to Port Aransas. The island is oriented generally northeast–southwest, with the Gulf of Mexico on the east and south, and Corpus Christi Bay on the north and west. The island's southern end connects by roadway to Padre Island. At the northern end of the island is Port Aransas, beyond which is San José Island. The Aransas Channel, also known as the "Aransas Pass," which separates Mustang Island from San José Island, is protected by jetties extending into the Gulf from each island.
The Canaveral National Seashore (CANA) is a National Seashore located between New Smyrna Beach and Titusville, Florida, in Volusia and Brevard Counties. The park, located on a barrier island, was created on January 3, 1975, by an act of Congress. The park is split between Brevard and Volusia counties, with 9 miles of the seashore in Brevard County, and 15 miles of the seashore in Volusia County. CANA consists of 24 miles of beaches, dunes, mangrove wetlands, and a large portion of the Mosquito Lagoon. The Canaveral National Seashore is also the longest expanse of undeveloped land along the East Coast of Florida. The Canaveral National Seashore is home to more than 1,000 plant species and 310 bird species. CANA occupies 57,662 acres (23,335 ha). There are 3 major beach sections in the seashore. The southern section is Playalinda Beach, the middle section is Klondike Beach, and the northern section is Apollo Beach.
Pea Island National Wildlife Refuge is a national wildlife refuge located on North Carolina's Pea Island, a coastal barrier island and part of a chain of islands known as the Outer Banks, adjacent to Cape Hatteras National Seashore. The sanctuary is located 10 miles (16 km) south of Nags Head, North Carolina on NC 12.
North Padre Island is a barrier island along the coast of Texas. It and South Padre Island were formed after the creation of the Port Mansfield Channel split Padre Island in two. From north to south, North Padre Island is located in parts of Nueces, Kleberg, Kenedy, and Willacy counties. The northernmost part of the island to the Kleberg County line is part of the city of Corpus Christi. Padre Island was once one island —today it is two and referred as North Padre Island, and South Padre Island. Padre Island National Seashore welcomed 674,704 visitors in 2020. Padre Island National Seashore is a national park that includes about 66 miles of undeveloped beaches and natural habitat. The national seashore is located on [North] Padre Island near the city of Corpus Christi, Texas. This national park is open 24 hours a day and seven days a week for visitors.
The Laguna Madre is a long, shallow, hypersaline lagoon along the western coast of the Gulf of Mexico in Nueces, Kenedy, Kleberg, Willacy and Cameron Counties in Texas, United States. It is one of seven major estuaries along the Gulf Coast of Texas. The roughly 20-mile (32 km) long Saltillo Flats land bridge divides it into Upper and Lower lagoons joined by the Intracoastal Waterway, which has been dredged through the lagoon. Cumulatively, Laguna Madre is approximately 130 miles (210 km) long, the length of Padre Island in the US. The main extensions include Baffin Bay in Upper Laguna Madre, Red Fish Bay just below the Saltillo Flats, and South Bay near the Mexican border. As a natural ecological unit, the Laguna Madre of the United States is the northern half of the ecosystem as a whole, which extends into Tamaulipas, Mexico approximately 144 miles (232 km) south of the US border, to the vicinity of the Rio Soto La Marina and the town of La Pesca, extending approximately 275 miles (443 km) through USA and Mexico in total.
The U.S. state of Texas has a series of estuaries along its coast on the Gulf of Mexico, most of them bounded by the Texas barrier islands. Estuaries are coastal bodies of water in which freshwater from rivers mixes with saltwater from the sea. Twenty-one drainage basins terminate along the Texas coastline, forming a chain of seven major and five minor estuaries: listed from southwest to northeast, these are the Rio Grande Estuary, Laguna Madre, the Nueces Estuary, the Mission–Aransas Estuary, the Guadalupe Estuary, the Colorado–Lavaca Estuary, East Matagorda Bay, the San Bernard River and Cedar Lakes Estuary, the Brazos River Estuary, Christmas Bay, the Trinity–San Jacinto Estuary, and the Sabine–Neches Estuary. Each estuary is named for its one or two chief contributing rivers, excepting Laguna Madre, East Matagorda Bay, and Christmas Bay, which have no major river sources. The estuaries are also sometimes referred to by the names of their respective primary or central water bodies, though each also includes smaller secondary bays, inlets, or other marginal water bodies.
The Mississippi–Alabama barrier islands are a chain of barrier islands in the Gulf of Mexico along the coasts of Mississippi and Alabama enclosing the Mississippi Sound. The major islands are Cat Island, Ship Island, Horn Island, Petit Bois Island, and Dauphin Island; in the early 20th century the chain also included the Isle of Caprice, which has since been submerged. The islands are separated by wide inlets, several of which have been channelized to form the shipping channels for Gulf coast ports. The shapes and sizes of the islands have changed significantly since the 1800s, with the islands generally shrinking and shifting westward, especially after major tropical cyclones. Most of the islands are uninhabited. Much of the Mississippi portion of the chain is included in the Gulf Islands National Seashore.
Port Mansfield Channel or Mansfield Cut is an artificial waterway encompassing the Laguna Madre positioned at the 97th meridian west on the earth's longest barrier island known as Padre Island. During Post–World War II, the tidal inlet was dredged as a private channel differentiating North Padre Island better known as Padre Island National Seashore and South Padre Island. The navigable waterway was channeled during the late 1950s ceremoniously cresting the intertidal zone of the Gulf of Mexico by September 1957 on the Texas Gulf Coast.
Sea Turtle, Inc. is a nonprofit sea turtle rescue and rehabilitation center in South Padre Island, Texas. It is a popular regional ecotourism center, seeing about a quarter million visitors per year. Its mission is to rescue, rehabilitate, and release sick and injured sea turtles; to educate the public about sea turtles and marine conservation; and to help conserve all sea turtle species, particularly those native to the Gulf of Mexico.
Perdido Key is a 24 kilometres (15 mi) long barrier island on the north coast of the Gulf of Mexico. The island extends from Pensacola Pass on the east to Perdido Pass on the west. Most of the island is in Florida, with the western end of the island in Alabama. Santa Rosa Island is to the east of the island, and Alabama Point is to the west. Perdido Key was attached to the mainland until the 1940s when a canal separated it from the mainland. The eastern part of the island forms part of the Gulf Islands National Seashore, which includes the Perdido Key Historic District, the site of three shore batteries that once defended Pensacola Bay. The rest of the island, with the exception of the Perdido Key State Park, has been developed as a resort and residential community. As a barrier island, Perdidio Key is subject to changes due to wave action and longshore currents, particularly from hurricanes. The endangered Perdido Key beach mouse is endemic to the island.
