A barrier island code named “GI Land” located along the U.S. Gulf Coast in an oil and gas producing province.  ‘

 

The island is roughly 2 miles from the mainland separated by a lagoon Barrier islands are long, narrow, offshore deposits of sand or sediments that parallel the coast line. Some barrier islands can extend for 100 miles (160 km) or more. The islands are separated from the main land by a shallow sound, bay or lagoon. Barrier islands are often found in chains along the coast line and are separated from each other by narrow tidal inlets, such as the Outer Banks of NC.

ended. As the glaciers melted and receded, the sea levels began to rise, and flooded areas behind the beach ridges at that time. The rising waters carried sediments from those

beach ridges and deposited them along shallow areas just off the new coast lines. Waves and currents continued to bring in sediments that built up, forming the barrier islands. In

addition, rivers washed sediments from the mainland that settled behind the islands and helped build them up.

 

Salt marsh - a low-lying area on the sound-side of a barrier island. Salt marshes are generally divided into high and low marsh areas. High marsh areas get flooded twice

each month with the spring tides, while low marsh areas get flooded twice daily with the high tides. Cord grasses stabilize the salt marsh area, which are one of the most

ecologically productive areas (amount of vegetation per acre) on Earth. Barrier islands serve two main functions. First, they protect the coastlines from severe

storm damage. Second, they harbor several habitats that are refuges for wildlife. In fact, the salt marsh ecosystems of the islands and the coast help to purify runoffs from

mainland streams and rivers. Each of these habitats has distinct animal and plant life, which we will discuss in the next section.

 

Beach Habitat

On the ocean side is the barrier island's beach habitat. The beach is much like a desert in that it lacks fresh water, but a large portion of the beach gets covered almost entirely with salt water twice daily (the entire beach gets covered to the dune base during storms). Animals and plants in this environment (known as the intertidal zone, between tides)

must endure long periods of exposure to salt water and drying air. On the beach, the only plant life you'll see is some algae that get washed ashore. Bacteria live in the spaces

between the sand grains where water from the surf percolates through. The animals on the beach itself include burrowing animals like mole crabs and clams that filter-feed

during high tides, burrowing worms that feed on bacteria in the sand, scavenging crabs (ghost crabs) and various shorebirds (sandpipers, seagulls and pelicans) that eat the crabs,

burrowing animals and offshore fish. http://science.howstuffworks.com/barrier-island2.htm

 

 Dune Habitat

The dunes receive moisture from rain and surf and are occasionally flooded during severe storms. The dunes are still a relatively hostile environment with high salt content,

sandy soil and little fresh water. Plants such as sea oats and bitter pancum provide stability to the dunes. Their root systems hold the sand in place and their shoots slow the winds, thereby allowing sand to be deposited. Along the dunes, you will find many crabs,particularly ghost crabs. Again, you will find birds (gulls, terns) that feed on the animals

that inhabit the dunes.

 

Barrier-flats Habitat

On other islands, the barrier flats come after the dunes. The primary vegetation includes cordgrass and sawgrass. These areas are often flooded daily during high tides. The muds and sediments are full of anaerobic bacteria (there is little oxygen in the sediments). The bacteria decompose the rich organic material in the sediments and from dead plants and animals. Animals that live in the wet muds filter-feed bacteria and plankton from the tidewaters or feed on bacteria in the muds; these animals include clams, mussels, snails and worms. Various fish come and go with the tides. Fiddler crabs feed on the bacteria in the muds. Ghost crabs and blue crabs feed on the bacteria, small invertebrates and small fish. Various birds (seagulls, egrets, pelicans) feed on the fish, crabs and invertebrates.