<P> Every year hurricanes represent a potential threat to the islands of the Caribbean, due to the extremely destructive nature of these powerful weather systems . Coral reefs can easily be damaged by violent wave action, and can be destroyed when a hurricane dumps sand or mud onto a reef . When this happens, the coral organisms are smothered and the reef dies and ultimately breaks apart . </P> <P> The region has a high level of biodiversity and many species are endemic to the Caribbean . </P> <P> The vegetation of the region is mostly tropical but differences in topography, soil and climatic conditions increase species diversity . Where there are porous limestone terraced islands these are generally poor in nutrients . It is estimated that 13,000 species of plants grow in the Caribbean of which 6,500 are endemic . For example, guaiac wood (Guaiacum officinale), the flower of which is the national flower of Jamaica and the Bayahibe rose (Pereskia quisqueyana) which is the national flower of the Dominican Republic and the ceiba which is the national tree of both Puerto Rico and Guatemala . The mahogany is the national tree of the Dominican Republic and Belize . The caimito (Chrysophyllum cainito) grows throughout the Caribbean . In coastal zones there are coconut palms and in lagoons and estuaries are found thick areas of black mangrove and red mangrove (Rhizophora mangle). </P> <P> In shallow water flora and fauna is concentrated around coral reefs where there is little variation in water temperature, purity and salinity . Leeward side of lagoons provide areas of growth for sea grasses . Turtle grass (Thalassia testudinum) is common in the Caribbean as is manatee grass (Syringodium filiforme) which can grow together as well as in fields of single species at depths up to 20 m (66 ft). Another type shoal grass (Halodule wrightii) grows on sand and mud surfaces at depths of up to 5 m (16 ft). In brackish water of harbours and estuaries at depths less than 2.5 m (8 ft 2 in) widgeongrass (Ruppia maritima) grows . Representatives of three species belonging to the genus Halophila, (Halophila baillonii, Halophila engelmannii and Halophila decipiens) are found at depths of up to 30 m (98 ft) except for Halophila engelmani which does not grow below 5 m (16 ft) and is confined to the Bahamas, Florida, the Greater Antilles and the western part of the Caribbean . Halophila baillonii has been found only in the Lesser Antilles . </P>

What are the bodies of water that surround the caribbean region