The Coral Reefs of the Dominican Republic

77 The coral reefs of the Dominican Republic Francisco X. Geraldes Centro de Investigaciones de Biologia Marina, Universidad Aut6noma de Santo Domingo and Fundaci6n Dominicana Pro - Investigaci6n y Conservaci6n de los Recursos Marinos, P.O. Box 748, Santo Domingo, Dominican Republic ABSTRACT: The Dominican Republic has a land area of 48,484 km2, with a coastline of 1,389 km, of these 166 km or 11% are coral reefs. The continental shelf, averages 7.5 km wide and covers 8,130 km 2. There are two submerged offshore banks, two barrier reefs, as well as many fringing reefs. Dominicans in general recognize the importance of coral reefs as they provide safe ports, shelter and habitat for biodiversity, food and beaches. The first report of reefs in the Americas was from Hispaniola by C. Columbus in 1492, calling them "baxas" or "roqueiros". Other early naturalist worked with specimens from this island, and research continues until our days. The reef setting varies depending on the location and distance form the numerous river discharges. Dry areas and shallow platforms are favorable for reef growth at: Montecristi, Macao-Punta Cana, Parque Nacional del Este, Parque Nacional Jaragua, as well as the Silver Banks located some 170 km to the north of the island. The coral coverage varies from 40% to 9%, reflecting not only natural causes, but also anthropogenic impacts. There are reports of 64 coral species. The coastal marine habitats including the reefs of all the marine protected areas in the country have been studied, cataloged and mapped, the information produced have been important for their management and conservation. Some reefs are under threat by development of ports such is the case of Boca Chica, the most studied reef site in the island. Sedimentation along the coast has increased, and has become a threat to reef growth, occurring on 1/3 of the coastline, and now reaching reef sites such as Juan Dolio and Barahona. Coral bleaching has been found mainly on areas near urban development. The 1980's mass mortalities occurred as in the rest of the Caribbean. The reefs of the southern and eastern coasts of the Dominican Republic are usually exposed to hurricanes. The reef tracks near urban development are more impacted by habitat degradation due to physical damage and from nearby sources of pollution transported by currents. Non-adequate beach use in some tourists centers have caused reef degradation in the past, lessons learned have induced the tourism sector to become involved in reef conservation. The main problem reefs are facing is overfishing of several essential species such as Strombus sp., Panulirus sp., and fishes of the Serranidae, Lutjanidae, and Scaridae families. Several non-official institutions as well as the recent created Secretaria de Medio Ambiente y Recursos Naturales (Ministry of the Environment and Natural Resources) have programs for conservation of marine and coastal habitats, communities and species. 1. INTRODUCTION The coral reefs of the Dominican Republic are an important resource, and it is acknowledged by the citizens that they provide safe ports, shelter, and food. Coral reefs have recently been associated with the tourism industry. While in the past, Dominicans took coastal and marine resources for granted, and considered them everlasting, there is Latin American Coral Reefs, Edited by Jorge Cortrs 2003 Elsevier Science B.V. All rights reserved. 78 F.X. Geraldes today an awareness of their fragility, and of the fact that they need care and good management to ensure their health and function. At present, coastal and marine environments, as well as forest habitats, have national economic, political and aesthetic value. Nevertheless, overfishing, pollution and urban growth still pose very relevant and real threats to these ecosystems. In order to minimize these, the country has set aside four large coastal regions as marine protected areas: Parque Los Haitises, Parque Montecristi, Parque del Este and Parque Jaragua. The last three are located downstream of oceanic currents and receive minimal river influence. In all coral reefs, seagrasses, and mangroves constitute important habitat reserves. Other coastal features of the Dominican Republic include emerged reef terraces, shorelines of terrigenous origin, estuaries and sandy beaches. This chapter includes a description of the coral reefs of the Dominican Republic, as well as maps of the most important reef sites: two barrier reefs (Montecristi and Macao- Bavaro-Punta Cana), and several fringing, hard base, high energy marine-coastal communities. Finally, a short review of the environmental hazards that coral reefs face in the Dominican Republic is presented. 1.1. Natural history The island of Hispaniola, situated at 17040 ' and 19~ and 68020 ' and 70~ is the second largest in the Caribbean (78,000 km2), and located in the north-central boundary of the Caribbean Sea. The deep Windward Passage (4,000 m) separates it from Cuba, to the north-northwest, and the Jamaica passage separates it from Jamaica, to the west-southwest (3,000 m). It is separated from Puerto Rico, to the east, by the shallow Mona Passage (350-400 m). Oceanic currents and winds are primarily governed by the easterly trade winds. Hispaniola is politically divided into two countries: Haiti to the west, and the Dominican Republic to the east (Fig. 1). The Dominican Republic has a land area of 48,484 km 2, with a coastline of 1,389 km. Of these, 376.7 km (or 27%) are mangroves, and 166 km (or 11%) are coral reefs. Emerged reef terraces and cliffs, are the main coastal features found along the coast, especially on the southeastern region of the island. The continental shelf has a mean width of 7.5 km, and covers an area of 8,130 km 2. There are two submerged offshore banks: La Navidad and La Plata, 70 and 150 km 2 respectively, located north of Cabo Saman~ (Fig. 1). 1.2. Geography The island topography is diverse, with three large valleys and four mountain chains. These have a directional trend northwest to southeast, with broad valleys in between. Two outstanding features of the Dominican Republic are: that it contains the deepest zone in the Caribbean (the Valle de NeybaJLago Enriquillo, at 48 m below sea level), and the highest peak (Pico Duarte/La Pelona, 3,087 m above sea level) (De la Fuente 1976). The island also has a very complex tectonic and geological history, being seismically active. 1.3. Climate and oceanography The climate of Hispaniola is considered to be tropical marine dry, with an annual average temperature ranging from 18 to 32~ at the lower elevations. There are regional variations in climate and rainfall, influenced by the predominant northeasterly trade winds, The coral reefs of the Dominican Republic 79 I ~.t ........ 69~ ?~. ;.-:.:::....... :. ~,~,~., ........ ..: Sliver Banks ,,,: ATLANTIC OCEAN - :............. ~ ~lOOm ......... .......... ) NavtdodShools ..::.~ .(2ayes Si'~tea~.mparelu e N,aclonal Punta ",H.errnanos Rucla de Montedrlstl ..... * .; "..~ree~ts ~,Lup .... Puerto ! ...,."...... .: . , ....~ YC~l,~]. t"~ ~ ~,~m-.- .... ..'''-. --; ., ...... : j ....... o 75~ HAl ~'" MONA PASSAGE ~o~u~L~ I , :"..."'. / \\ c::V, e0" .: "~"7~"~ Ca~'~ ~~i~ d'''''.'." ...... i'Jm tk:lrah~ :''eels" :~'~i1~ ......... ~sla~tt, ,/ IslaBeatq ;ee~ ..." CARIBBEAN SEA Alto _"...... "lOOm Velo r Fig. 1. Dominican Republic coral reef localities. as well as cold fronts from the northwest, and sporadic hurricanes and summer storms from the southwest. Rainfall tends to decrease from east to west. The annual average rainfall is 980 mm, with May and November having the highest precipitation, and December to April having the lowest. The oceanic circulation patterns in coastal waters are dominated by the Northem Equatorial Current, which flows westward and divides itself into northem and southem branches at Mona Passage (Metcalf et aL 1977). Counter currents, usually associated with tides, are common near to the coast. Tides are semi-diumal, with mean spring tidal ranges of 90 and 30 cm on the northern and southem coasts respectively. 1.4. Culture, population, and development The people of the Dominican Republic form an agricultural and farming society, which is presently moving towards light industry and tourism. Historians indicate that defores- tation and human intervention in the natural setting has occurred since the 15 th century. Severe environmental changes occurred during the early to middle 20 th century, when the sugarcane industry boomed and large areas of forest were cut down, increasing soil erosion and sedimentation, and hence ultimately affecting the nearby marine ecosystems. 80 F.X. Geraldes Another major impact to the environment has been the recent population rise, from 2.5 million in the 1960's to the present 8.5 million today. This rise has increased the degradation of watersheds, river systems, and marine and coastal habitats. 1.5. Coral reef research The study of reefs in Hispaniola began in 1492, when Christopher Columbus described these submerged structures as "roqueiros", "baxas" and "restringas" (confinements) in his navigation log (Col6n 1492). Later, in 1525, Gonzalo Femfindez de Oviedo (in Chardon 1949) mentions these strange formations on his Sumario de la Natural Historia de las Indias. Several early naturalists, such as Carlos Plumier (1695 in Chardon 1949) and George L. Leclerc (1770 in Chardon 1949) made collections for the Muse6 de Historie Naturelle de Paris. In 1776, Luis Nicolson published his Essai sur l'Histoire Naturelle de St. Domingue (Chardon 1949), where he mentions madreporaria, corals, crustaceans, and other invertebrates. Also worth mentioning is the work of Moreau de Saint-M6ry during 1796 (Chardon 1949) and his Description Topographique et Politique de la Partie Espagnole de L'Ile de Saint Domingue. Later in the 19th century, more works followed such as those of William Gabb (1868, in Chardon 1949), who published "On the Topography and Geology of San Domingo". In the early 1900's, other scientists such as Vaughan (Vaughan 1900; Vaughan et al.

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