The coastal zone contains some of the planet’s most productive ecosystems with rich biodiversity reserves. The coast also supports the majority of the planet’s human population. In the Wider Caribbean, as elsewhere, the coastal zone is integral to the social and economic life of the region, and has been so ever since the first settlers arrived in the area. An estimated 40% of the human population in the Wider Caribbean region resides within two kilometers of the coast. Loosely defined, the coastal zone includes both the area of land subject to marine influences and the area of the sea subject to land influences. A more rigorous definition divides the coastal zone into three main components: the sea, the beach, and the land behind the beach. The sea, or offshore area, extends from the low water mark seaward. This area covers the shallow marine habitats of the coast, such as the seagrasses, and the coral reefs among others. The beach zone extends from the low water mark to the seaward edge of the coastal vegetation. In some cases the base of a cliff or a dune may mark the end of this highly changeable environment. The last component of the coastal zone is the adjoining coastal land. This zone extends landward for some distance from the end of the beach. The definition of how long this distance is may vary according to each country. As with all environmental systems, there are no clearly defined and universally accepted boundaries to the coastal zone.

Land contour

Where the land is flat, the coastal zone may extend for a considerable distance inland, and may consist of sand dunes, swamps or lagoons. Where the land is steep, the coastal zone may be very narrow. The definition also depends on aspects relating to the ease of management of the coastal zone. The narrower the area covered by coastal zone is considered to be, the easier it is to manage. The wider it is, the more complicated the environmental systems and the more numerous the agencies involved in the management process. The three subsystems described here interact in many ways, and the boundaries between them fluctuate. The coastal zone is not an isolated system. Rivers and waterways may carry pollutants and sediments resulting from inland activities to the coast, where they have an impact on coastal zone habitats. Agricultural and forestry practices, for example, are known to bring increased sediments and chemicals to the marine environment, where they may degrade the health of the coral reefs. Water currents may carry pollutants from one country’s coastal zone to another’s. The coastal zone is a complex, highly productive environment, and the health of one ecosystem is intimately tied to the health of the other ecosystems in the area, and often to areas some distance away.