Rising Sea LevelRising sea levels have been disturbing geographers and geologists forsome time now. Scientists are constantly trying to prevent the effectsrising waters are causing, which mainly includes beach and island erosion.So far, their attempts with man-made development on beaches along the easterncoast of America have only made things worse.”Up and down the U.S. coast, public money is subsidizing private propertyon islands made of sand, the stuff on which, as the Bible says, only foolsbuild” (Ackerman 7). In recent years there has been a trend towards livingon the barrier islands of America’s Atlantic Coast.
High rise condominiums,numerous shops, and several businesses have been built to sustain largepopulations on these islands and continue to be built. As a result, thisvital chain of islands that lies between the ocean and the mainland areat risk.While interfering with the natural configuration of these islands, humanconstruction has advanced the rate of beach erosion, thus leaving the mainlandwith no barriers during times of high surf. This effect has also led tocostly, unnatural ways to preserve the barrier islands. Saving these islandsin their natural state by curbing human encroachment will both protectmainland populations from high surf and save a considerable amount of federalmoney. The barrier islands are a chain of islands, stretching from NewYork to southern Texas, that have served as a critical barrier from theAtlantic Ocean for well over the past 4,500 years (Ackerman 23).These islands however are not as stable as those who live on them wouldlike it to be.
Beaches, and in fact whole islands, are constantly erodedas they are subjected to varying winds, currents and changing sea levels.Along Florida’s East Coast, roughly 368 miles, the average shoreline changeis retreating 22cm per year. Under natural conditions, native vegetationand shifting sands constantly replace or withhold sand on the islands (16).Unfortunately for the inhabitants of the barrier islands, this is a geologicalbehavior which can only continue if the islands remain in a natural state.In recent years humans on these shorelines and islands have been respondingto the naturally changing conditions, through the use of man made structuressuch as seawalls, groins, and sand replenishment, in an effort to savebeachfront property from erosion.
Obstructing the natural shifts of the islands, says Orrin Pilkey ofDuke University who has studied these islands for thirty years, will causethem to, “be lost forever” (16-17). Attempting to hold beaches in placewith the use of seawalls, groins, and sand replenishment may seem likea good solution in theory, but in practice they probe ineffective. Oneof the most common methods of attempting to hold barrier island beachesin place is through the use of sea walls, which are costly and ineffective.
Seawalls are typically cement walls constructed parallel to the seashorein an effort to block waves from coming over the beach and into property.However, seawalls tend to withhold sand behind the wall during times ofhigh surf and the natural tendency of the beach to respond to waves isdisturbed (Kaufman 207).The structures commonly fail from undermining or erosion by waves breakingover their tops. Under normal conditions sand would be spread out by outgoingcurrents, which in turn would lower the slope of the beach and cause thewaves to break gradually. With seawalls in place, sand remains stationarywhile waves erode the beach as wave energy is deflected against sand notprotected by the seawall (208).
In addition to advancing the erosion rateof the sand and inhibiting the beaches’ natural tendencies, seawalls havebecome quite costly to maintain. For example, in New York $120 millionwas paid by the federal government to sustain and replenish seawall installationsas of 1996, and repairs continue to be made (Dixon 231). Clearly, thismethod is both costly and ineffective.
Another commonly used method ofstopping erosion is the placement of groins, which are also ineffective.Groins are pilings of rocks that extend into the ocean and perpendicularto the shore. Like seawalls, the primary purpose of a groin is to trapsand, but in longshore currents rather than sand deposits already on thebeach.Contrary to their intended purpose, these structures trap sand on theside facing a longshore current and leave the opposite side without sand(Kaufman 207).
Over time, the side not facing longshore currents erodesand the initial problem reoccurs. Once again, after the unsuccessful useof groins, money and resources must be spent to restore the beach.