xvii (such as pollution) or indirect (such as population increase leading to pollution): they can be local drivers (such as habitat destruction) or extemal ones (such as global climate change). By analysing these drivers, it becomes possible to understand bellcr the lull consequences of particular policies or activities on the well-being of our societies, and to suggest the type and scale of changes which may be required to reduce the stress on ecosystems. It is important to note that ecosystem change is olien the result of two or more of these ll!ctors working together·· l(Jr example, a healthy coral reef may be able to withstand the introduction of a disease organism, but that same disease could have a devastating impact on another reef already weakened by the ellccts of nutrient pollution or overlishing. The main drivers aJlccting the Caribbean Sea arc set out in Table 3.1. Here arc some of the key examples in each category: Local, direct Changes in coaslal land and sea use in the Caribbean have been the single greatest cause of ecosystem damage. Flat land along the coastline and reclaimed from the Sea has been used for industry and commerce. and in a wide range of tourism developments such as hotels, apartments, and golf courses. The consequence has been severe depletion of habitats such as seagrass beds and mnngroves, damnge to coral reefs. and the dcstabili;wtion of beaches. Sewage polllllion from land sources and from cruise ships has been the most p<:rvnsive lorm of contamination of the coastal environment. Apart from aiTecting bathing beaches and thereby the tourism potential i(Jr particular areas, the elevated nutrient levels from such pollution can overstimulate the growth of algae, causing fish kills and coral damage. Ove1.'/ishing through the increasingly widespread usc of certain types of gear is pulling unprecedented strain on the fish stocks of the Caribbean. Locul, iutlirect Urbanization of coaslal communities has been the major lllclor underlying the direct pressures on the Caribbean Sea ecosystem. High tourism depeudenc:v has led to a massive amoulll of capital investment in coastal inlrastmcture, which has, in turn, damaged the capacity of the ecosystem to provide services to the region. Lack of co-ordina!ed gm•emance in the region has led to a competitive rather than co-operative approach to issues such as fish stocks and tourism management. to the detriment of the ecosystem. Extenzal, tlirect Glohal climate change can potentially have a profound impact on the Caribbean Sea ecosystem. Increased intensity nnd frequency of tropical storms have devastated the tourism industry of some islands, and the overall scale of destruction has been exacerbated due to the increased population along the coasts. Rising sea temperatures, mcnnwhile, have increased the incidence of coral "bleaching." River disduu:f?e lrmn the Magdalena, Orinoco, and Amazon basins can cause significant damage to the marine environment of the Cmibbean, through an excess of sediments or contamination resulting from deforestation or pollution in distant regions. Alien ·'1Jecies in!rocluctions arc thought to have caused ecological damage when marine creatures were carried in the ballast tanks of ships, and even dust particles !rom the Sahara Desert arc implicated in spreading disease organisms to Caribbean reef species. Extemal, iudb·ect /ntemational shipping rules under the United Nations Convention on the Law of the Sea (UNCLOS) grantloreign vessels the right of"innocent passage" through Caribbean waters, exposing the ecosystem to extra pressures of pollution, overfishing, and even the risk of radioactive contamination from shipments of nuclear material. The combined impact of these drivers is that the poorest economics and communities of the Caribbean arc prone to sutTer the consequences of changes to the marine ecosystem, while enjoying few of the benelits that accrue from exploitation of its resources. For example: the leastdeveloped countries and territories arc especially vulnerable to the damage caused by more destructive storms; smallscale fishing communities arc unable to compete fairly with bcucr-cquippcd f1cets lor scarce stocks; local people arc sometimes prevented !rom enjoying coastal resources as space is taken up by "enclave tourism" and other uses benefiting more prosperous sections of society; and lack of co-ordinated govcnmnce prevents more of the profits from tourism lrmn being returned to local economics. - 19-