Sand dunes and beaches

Picture courtesy of NOAA.

Dunes and beaches have an important coastal protection function. They represent flexible barriers, which absorb wave energy during storms by moving and adjusting their shape and position. Furthermore, they form a crucial natural resource as a unique habitat for rich and diverse communities of highly specialised plant and animal species. However, their proximity to the ocean has made them desirable sites for locating coastal real estate. Such alterations to the coastline, as well as beach mining and renourishment, dredging, and filling are of particular concern in coastal areas because they have considerable environmental impact.

Construction of hotels and tourism facilities reduces sediment movement blocking natural shoreline retreat. As a consequence, the beach backs up against these artificial structures, having nowhere to retreat. This leads to a narrowing of the beach, as well as a reduction in the supply of sand on adjacent beaches. Three-quarters of the sand dunes on the coastline between Spain and Sicily have disappeared, mainly as a result of urbanisation linked to tourist development. A few years ago, Jamaica's beaches were lined by sand dunes. They were covered with vegetation that exhibited an extensive root system, thus binding the sand. However, the construction of numerous buildings and hotels, and the heavy use of public beaches have led to the erosion of the dune system. Beach sand mining, a common practice especially in the Caribbean region, causes sedimentation, which has a negative impact on coral reefs and other marine ecosystems. In Cuba, sand from the famous beaches east of Havana has been removed for the construction of buildings. Similarly, dredging not only physically alters marine ecosystems, but also causes the re-suspension of large amounts of sediment. Increased tourism activity itself leads to excessive local erosion due to excessive trampling and disturbance to wildlife. Tourism's impact on the critically endangered Mediterranean monk seal has been particularly devastating. This mammal needs suitable cave and beach habitats in order to breed successfully ' areas that are exploited by the tourism industry. Already the tourism industry has played a major role in the decline and extinction of Mediterranean monk seal populations in several key areas including France and Corsica, Spain and the Balearic Islands, Croatia, Italy and Sardinia, and Tunisia.

Picture courtesy of NOAA.

Damage to sand dune habitats can partly be mitigated through restoration and rehabilitation measures. In Anguilla, Hurricane Louis (September 1995) caused extensive damage to the island, including its coastal environment. Dune fences made of wooden pallets were constructed on the sites ' in order to speed up accumulation of sand. Soon after the fences were deployed sand accumulation was observed along the structures and natural vegetation, especially sea lavender (Tournefortia gnaphalodes) promptly colonised the newly accumulated sand, further stabilising the dunes. Honolulu has dealt with the erosion problems associated with shoreline development by promulgating strict shoreline setback requirements and severely restricting all shoreline breakwaters and other structures that "harden" the coast.