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This region also includes the long coastline of Venezuela and although there is virtually no reef development along this shore, there are important reefs associated with the chain of islands located offshore to the north. As with other areas of the Caribbean, the reefs of the Eastern Caribbean have suffered considerably from the combined impacts of the Diadema die-off and coral disease. Many of the more northerly islands have also suffered damage from hurricanes. Tourism is the greatest industry in this region and vast numbers of visitors have fueled rapid and poorly planned coastal development, with associated problems of sedimentation and pollution that always follow such development. The region also contains a number of well protected areas as well, notably those off Saba, Bonaire and St. Lucia, which have been especially well managed, leading to the recovery of healthy reef ecosystems in localized areas. These provide a model for reef management throughout the region. Beyond the Caribbean, there are some important and well developed reefs and coral communities along the coast of Brazil. Although still poorly known, these reefs are receiving considerable attention. In the few scattered islands of the Central Atlantic and along the less turbid areas of the West African coastline some important coral communities are also recorded.
Haiti is the most impoverished country in the western hemisphere, so the reefs there are likely to be under intense pressure from the local populations. Less than one percent of the native terrestrial vegetation remains intact and the island's steep relief and high rainfall cause widespread and severe soil erosion, which is likely to have a direct negative impact on the coral communities. About seventy five percent of the population lives in poverty and consequently almost all fishing activities are carried out at the subsistence level, and reports indicate that the fishing pressure is so great that very few fish reach reproductive size. There are no sewage treatment plants or sanitary landfills and the level of nutrient pollution flowing onto the coral reefs has to be very high because of that. There are currently no protected marine areas in Haiti. All in all, a dire situation for the coral reefs of Haiti, to say the least.
The Dominican Republic makes up the larger, eastern part of the island of Hispaniola, and like Haiti, it is mountainous with considerable river runoff. Fringing reefs and small barrier reefs are scattered along the 170 kilometers of coastline, and there are important reef communities on the offshore banks of Navidad and La Plata which lie to the north of the country. The best developed reefs include a small barrier reef in Montecristi in the northwest, some narrow fringing communities along the central north coast and in the east on the mainland and the neighboring Isla Saona. Coral cover has declined considerably in most of the near shore areas, and algae have proliferated at the expense of coral reefs in some localities. High coral cover is now largely restricted to the deeper reefs, and to those lying farther offshore. An important protected area is the Jaragua National Park which protects many different coastal ecosystems. There are large and regionally important populations of manatees, crocodiles, turtles (leatherback, green, hawksbill and loggerhead turtles all nest there) and flamingos. Many of the reefs around Santo Domingo and in the north have been severely impacted by human activities. Sedimentation (from upland deforestation, wetland removal, soil erosion and coastal construction for the tourist industry), nutrients (from fertilizers and domestic wastewater) and pesticides (from agricultural runoff) are the main causes. Reefs in the south have suffered less impacts, and over fishing, in both the north and south, continues to be a problem, especially of conch and lobster. About twenty percent of the coral reefs in the Dominican Republic occur within marine parks and sanctuaries, and the majority of these occur in the Jaragua and Del Este National Parks. Management levels in the parks is limited however, and many continue to be heavily fished. The parks near Haiti are regularly and heavily poached by vessels from that impoverished country. Navassa Island is a United States territory since 1877 and has no permanent inhabitants. An uplifted limestone structure of around five square kilometers, it has important coral reef communities on all sides. There are few human impacts here and although there is some fishing by Haitians.
Puerto Rico has one of the most thriving economies in the Caribbean and tourism has traditionally been a very important industry, with over 4 million visitors every year. Construction and tourism both have had considerable negative impacts on the coral and other marine communities on the island. Clearance of over seventy-five percent of Puerto Rico's mangroves, combined with dredging, agricultural runoff, pollution from untreated sewage, and sedimentation from forest clearance have had considerable impact on most coastal reefs. Over fishing of large predator fish, parrotfishes and spiny lobsters is widely reported, and oil spills have impacted some areas in devastating ways. The offshore island of Vieques is used by the United States military as a bombing range, resulting in many craters on the reefs there measuring some 5-13 meters in diameter. Whether the positive impacts associated with the exclusion of fisherman and tourists from these reefs by the military compensates from this destruction is still a mater of controversy. Efforts to control some of the more damaging activities and protect some of the reefs from further decline are happening and a number of marine protected areas have been designated, together with seasonal fishery restrictions on some spawning fish populations. Legislation is being developed also to address some of the marine pollution problems of the island. The United States Virgin Islands have coral reefs that are widespread around all of the islands. Mostly they are fringing reefs, but there is a small barrier reef off St. Croix, and a number of offshore patch reefs and bank structures. Nowhere in the Caribbean have the combined effects of hurricanes and disease on coral reef population structure been more pronounced than in the Virgin Islands. Hurricanes Hugo (1989), and Luis and Marilyn (1995) had devastating impacts on local reefs, and coral disease has also been widespread. A typical example is the eighty percent loss of Acropora palmata colonies in Hawksnest Bay in a period of only seven months due to coral disease. Tourism, as on most Caribbean islands, is the main industry and significant damage has occurred from boat anchors and ship groundings. The Virgin Islands National Park on St. John attracts a million visitors a year, mostly arriving on cruise ships or smaller boats, and an estimated 30,000 anchors are dropped each year. In 1989 the cruise ship Windspirit destroyed some 300 square meters of coral reef with its anchor and chain and there has been very little recovery since. This resulted in the successful prosecution of the boat owners by the park authorities and remains one of the few examples of such action for damages incurred to coral reefs by human activity. Additionally direct damage by divers and snorkellers has also been recorded at the most heavily used sites. Mooring buoys were recently installed but unfortunately there is very little coral left to protect and no limits have been set on the size of vessels allowed in park waters. Over fishing is widespread throughout the islands, even within protected areas. This situation is further exacerbated by the widespread loss of fish habitats, including seagrass and mangroves areas, such that fish stocks are highly depleted in most areas of the US Virgin Islands. Other continuous threats include sedimentation, land clearance, coastal development and sewage discharge (the eutrophication of some reefs in the area has been attributed to leaching from septic tanks during heavy rains). One of the world's largest petroleum refineries is at St. Croix, which also represents a significant potential threat to coral reefs as well. On a bright note, in 1999 a Marine Conservation District was declared to the southwest of St. Thomas. Known as the Hind Bank, the area is closed to all fishing and anchoring, and represents an important step in the right direction towards fisheries management and coral reef conservation in the area. The British Virgin Islands also are home to considerable coral reef communities, including fringing reefs close to most islands, patch reefs in offshore areas, and a long barrier reef structure, Horseshoe Reef, extending to the southeast of Anegada. As with the US Virgin Islands, the reefs here have also been severely impacted by recent hurricanes and in some cases 100 percent of coral cover was lost. Human impacts vary across the islands but deep loss has been noted nearer the more heavily populated areas as one would expect. Coastal development has been particularly severe on Tortola and Virgin Gorda, with the destruction of almost all of the mangrove habitats, and considerable increases in sedimentation have resulted from road building and other coastal construction. These islands have the greatest concentration of charter yachts in the world and anchor damage is widespread and significant, and there is some eutrophication in the more enclosed bays which is due in part to these vessels. Although marine protected areas have been declared in the British Virgin Islands, active management is limited.
There has been progressive degradation of the reefs of the Lesser Antilles as a whole over the past twenty years, with loss of coral cover, algal growth on reefs and decline in number and average size of fish populations. Impacts have been varied on different islands with Antigua and Barbuda, Montserrat, Guadeloupe, Martinque and Barbados leading the way in islands that have the greatest loss of coral communities due to tourism, construction associated with tourist growth and natural impacts from hurricanes.
Venezuela also has jurisdiction over a number of offshore islands, most lying in deep oceanic water at considerable distance from the continental shelf. These include Las Aves, Los Roques, Isla la Orchilla and la Blanquilla which lie in a chain parallel to the coast. These reefs have a great number of different species, including over 270 species of coral reef fish alone. The principal threat to these reefs is over fishing since reef based tourism is not yet developed. Aruba, Bonaire and Curacao are islands that also have extensive coral reef development. Aruba is located on the continental shelf only twenty seven kilometers north of Venezuela and Bonaire and Curacao are oceanic islands surrounded by deep water. The reef profiles of Bonaire and Curacao are very similar: a submarine terrace extending between 50 and 100 meters offshore and ending in a drop-off at a depth of 8-12 meters which slopes steeply down to 50-60 meters. Prolific coral growth occurs on the underwater terrace and on the shallower slopes. Aruba on the other hand, since it is located on the continental shelf, does not have sharply sloping underwater relief. Bonaire is considered one of the region's best examples of a self-financing marine park. Divers are charged a fee per year for use to dive on the reefs, contributing about sixty percent of the running costs of the park, with a significant proportion of the remainder being generated from the sale of souvenirs. Studies have shown than the user fee is seen as a positive thing by the majority of visitors, raising awareness of conservation issues while giving them some sense of participation and ownership.
The eastern continental shelf of Brazil has narrow reefs, also with low species diversity. In the State of Bahia, the continental shelf widens considerably, extending from 5 to 65 kilometers offshore, and reaching over 200 kilometers in the far south around the Abrolhos Archipelago. This is the richest and largest area of coral reefs in the South Atlantic, with fringing reefs and offshore banks abundant. Many of the coast reefs of Brazil exhibit signs of degradation, especially those close to human settlements. The expansion of tourism, increased sedimentation from inland deforestation for agriculture and rapid coastal development West Africa does not have any true reefs although mature coral communities are found at various locations. In all some fifteen species of coral have been recorded. There is considerable river drainage along the coastline and warm, low salinity water is a permanent feature. These and other oceanographic factors combine to inhibit coral reef formation, with only two different types of coral communities that have been described. Very little is known about sub-tidal benthic communities over wide areas of West Africa and it is quite possible than there are important and diverse coral communities in a number of areas that have yet to be discovered.
Extracted and adapted from The World Atlas of Coral Reefs, by Mark D. Spalding, Corinna Ravilious and Edmund P. Green, published by the University of California Press . For more complete and in-depth coverage of the topics presented in this webpage, I recommend highly purchasing a copy of this beautifully illustrated book. Just click on the University of California Press link above to do so.
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