Note: We are currently updating the ecosystem profile for the Caribbean Islands Biodiversity Hotspot. Information below is based on the 2010 ecosystem profile.
Humans arrived in the Caribbean about 4,000 years ago. However, it is only in the last 500 years that significant environmental degradation has occurred, beginning with the arrival of the first Europeans on Hispaniola in 1492. The initial wave of forest clearing began in the early 1500s, for sugar cane plantations. Sugar cane, which has led to widespread deforestation throughout the region, is still the Caribbean's most important crop.
Invasive species and infectious diseases
Like other islands, Caribbean habitats are vulnerable to impacts of invasive species because of the generally small populations of indigenous species, evolutionary effects of isolation (such as loss of defensive behaviors) and the release of introduced species from natural enemies. The spread of invasive aliens is generally considered to be among the greatest threat to the native biodiversity of the hotspot.
Emerging infectious diseases are a newly recognized threat to biodiversity globally and in the Caribbean, and amphibian chytridiomycosis is a striking example of this threat. Caused by the recently described chytrid fungus (Batrachochytrium dendrobatidis), chytridiomycosis is capable of driving amphibian populations and species to extinction.
Within the Caribbean, the amphibian chytrid is known to occur on the islands of Cuba, Dominica, Montserrat, Puerto Rico and Tobago. The disease has been implicated in the decline of one of the world’s largest frogs, the Critically Endangered mountain chicken (Leptodactylus fallax), on Dominica and Montserrat and is suspected in the probable extinction of three species from Puerto Rico. Chytridiomycosis presents a unique challenge for biodiversity conservation because the pathways of transmission and the way it kills amphibians are not well understood.
The population and economies of most Caribbean countries have grown considerably in the last 50 years, leading to extensive development and much of which has occurred without adequate planning. This has led to the destruction and degradation of huge areas of natural habitats, transforming the coastal landscape and character of many Caribbean islands.
Impacts have included pollution from untreated sewage from residential and tourism developments and contamination from industrial sites; clearance of natural coastal vegetation for construction; clearance, dredging, channelization or in-filling of coastal wetlands and mangroves for marinas and ports; sand mining and beach and dune erosion; and increased consumption of water from surface and ground water sources leading to salt intrusion and changes in ecosystem function, and decreased availability of water supplies.
Of greatest concern has been the uncontrolled growth of tourism in the Caribbean region over the past five decades, with the widespread construction of hotels, marinas and associated developments, especially along coasts with white-sand beaches and coral reefs offshore. These are typically leeward, low wave energy beaches preferred by remnant populations of Critically Endangered hawksbill turtle (Eretmochelys imbricata) for nesting.
Development has often meant the removal of natural littoral vegetation, planting of ornamental trees, shrubs and grass for lawns and golf courses, filling-in of mangrove areas for marina developments and mosquito control, and construction of new roads to give access to coastal areas that previously could only be reached on foot or by sea.
Even legally protected areas have not been immune to tourism development pressure especially when it involves major international investment. In recent years, some Caribbean governments have moved to change and undermine the legal status of previously protected conservation sites to facilitate tourism development.
Severe weather and climate change
The Caribbean is one of the most hurricane prone regions of the world. To a certain extent, Caribbean ecosystems are adapted to these extreme storms, and they have been a driving force for evolutionary change. Consequently, in one sense these natural phenomena cannot be considered a threat except that the loss of resilience of biodiversity due to reduction in population sizes and fragmentation from human activities increases their impacts and the risk of extinction.
The loss, fragmentation and degradation of natural habitats in the Caribbean islands, especially in the last 50 years, has reduced the resilience of the region’s remaining biodiversity to survive hurricanes and tropical storms, with species possessing small and often isolated populations (many threatened species) and specialist groups, such as montane nectar-feeding and fruit-/seed-eating birds (which may lose virtually all of their food sources from the storm), particularly at risk. Hurricanes in the Caribbean are predicted to increase in intensity and possibly frequency under current climate change scenarios.
Read more about these and other threats in our 2010 ecosystem profile (PDF - 1.7 MB), also available in French (PDF - 2.6 MB) and Spanish (PDF - 2.6 MB). An updated version of the ecosystem profile will be published in 2018.