Erosion of Shorelines
The erosion of shorelines is a natural process that can have beneficial or adverse impacts on the creation and maintenance of habitats. Sands and gravels eroded from the shores of coastal bays maintain the beach as a natural barrier between the open water and coastal wetlands. Beaches move back and forth onshore, offshore and along shore with changing wave conditions. The finer-grained silts and clays derived from the erosion of shorelines are sorted and carried as far as the waters of wetlands or tidal flats, where benefits are derived from addition of the new material.
The Environmental Tragedy of Coastal Erosion
A very high percentage of the American population resides at or near one of the coasts. Preserving beaches is a very costly endeavor and there have been many debates over which way this country should go about doing so. On the east coast the current strategy is, “beach nourishment programs”, whereby sand is taken from available sources and put back onto the eroded beach (Michaels, 01).
Surfers, swimmers and sunbathers use beaches for recreation. People fish off beaches for food. Since many people take their vacations at the beach, lots of beaches in tropical locations are important to their country’s economy. Entire cities, regions and countries depend on the money tourists spend while visiting the beach. Beaches are naturally very dynamic places, but people try to control them and build permanent structures, such as houses, restaurants, shops and hotels, on or near the shore. The natural erosion and deposition of beaches becomes a problem. Beaches con disappear over time, or even over night during severe storms. Beaches are areas of loose sediment (sand, gravel, cobbles) controlled by ocean processes. Most beaches have several characteristic features. First are offshore bars, which help protect beaches from erosion. Next is the foreshore, which rises from the water toward the crest of the next feature; a berm. On low-lying shores, dunes form behind beaches. Dunes look like rolling hills of sand and are blown into place by the wind. New, smaller dunes are often changing shape as the wind continues to affect them. Waves and currents move the accumulated sediment constantly creating, eroding and changing the coastlines.
There are many different types of coasts that exist throughout the United States. The south shore of Long Island has a unique types of coast known as a barrier beach. Barrier beaches are long narrow land forms that are composed of sand and other lose sediments. These sediments are brought together by the actions of waves, currents and storm surges. Barrier beaches are subject to constant changes by the same forces. Sand is constantly eroded in one area an deposited in another. Barrier coasts are important for a number of reasons; they protect the mainland of Long Island from the open ocean and flooding during storms, for recreational use and the unique ecosystems which exist on barrier beaches.
Abiotic factors are things that are nonliving that influence an environment and it's inhabitants. Some of the abiotic factors that are attributed to coastal erosion in Louisiana are hurricanes, tropical storms, elevation, sunlight, overnutrition, sea-level rise, and deposition. Hurricanes bring about larger waves which cause dune erosion or beach erosion (Clark et al., 1998). This is significant because beaches and/or the dunes of the beach serve as buffers to the coastline and the ecosystem. As the beach or dunes recede from the erosion caused by these large waves and an increased sea-level the flora and fauna that help sustain the area die off or retreat to a more habitable zone leaving the wetlands in a critical state often resulting in a total loss of the area (Stockdon et al., 2012). Due to the nature of the Gulf of Mexico large destructive storms such as hurricanes or tropica...
Semaphore Beach is affected by many factors such as natural processes and human impacts including marine litter and the discharge of stormwater. Therefore, several plans have been employed to ensure that the coast is supported through the method of counteracting erosion. However in the future, many management strategies have been put into consideration as well as the environmental, economic and social impacts as well as the predicted consequences. These impacts include traffic related incidents, noises and air pollution and the disruption of wildlife and the erosion of dunes. A method that should be considered for future management of the beach is the use of a concave sea wall, although efficient, this structure would be quite costly. Without the use of coastal management, Semaphore Beach would be unsupported, therefore negatively being affected by a variety of
Although, long shore current and the resulting transport of sediment is only one of the dynamic processes that constantly alter the shoreline. As waves repeatedly hit the shore, water moves onto the beach and then retreats in a continuous cycle. However, the waves are not all that moves on the shoreline. In fact, the sediment on the shore is also always on the move. Great energy is expended on the beach as waves crash against the shoreline. This energy allows the water to transport sediment. The grains are lifted as the waves in the swash zone move onto the beach, and then the grains are deposited again as the water retreats. As long as the waves hit the shoreline “straight on”, the wave crests are parallel to the shoreline, the sand grains will be picked up and redeposit in the same general area. In this case, no real net movement of sand occurs in the swash zone.
In south Texas there are several types of ecosystems one of those ecosystems are the dunes. South Texas dunes are found along the Texas coastline and the general abiotic conditions are sandy soil, high salt content, some fresh water, flooding in the occasion of severe storms and moisture from rain and waves. Sea Oats and Bitter Pancum are two types of plants that dominate the South Texas dunes. Bitter Pancum adaptation for living in this type of ecosystem is that they are tolerant to high salinity. Sea Oats are less tolerant to high salt but their adaptation is to grow rapidly. Some common animal species that live in the dunes are crabs, which are tolerant to high salt water, gulls, and terns feed on crabs and other species around the dunes. Dunes play a vital role in our first line of defense from flooding and storms by providing a protective barrier. Dunes also play an important role in our economy because they attract tourist to visit the local beaches in the South Texas coastline. Human activities pose a threat to dunes because they accelerate the natural damage that is happening as well destroying vegetative cover and help the development of breaches.
Sonu, Choule, and Johannes Beek. "Systematic Beach Changes on the Outer Banks, North Carolina." The Journal of Geology. no. 4 (1971): 416-425.
At its simplest, shoreline erosion is the result of the combination of processes, both natural and manmade, by which shoreline and beaches are damaged or lost. For this discussion, wetlands are also included. There is an ongoing debate over the best way by which to preserve beaches, shorelines, and wetlands. Conservation extremists argue that limiting or restricting land use, and restoring damaged property with tax money represents the most prudent answer to shoreline erosion. Included in this position is the inherent role of government intervention to preserve America’s shoreline. There are many problems with the conservation position, and many advantages to the alternate solution --- private development and corporate funding.