Fifty thousand ships and 14.5 million tourists visit the region every year.
Other concerns center on the rising tide of household and industrial wastes contaminating the land, underground freshwater supplies and coastal waters. For example, only 13 per cent of the population of Saint Lucia is connected to the sewage system.
Dwindling quantities of freshwater for drinking and agriculture is a worry in many islands. Some countries in the eastern Caribbean, like Antigua and Barbuda, Barbados and Saint Kitts and Nevis, are already officially listed as "water scarce".
Tourism in the form of luxury hotels and golf courses can intensify the problems unless carefully managed. Tourist resorts use on average of five to ten times more water than similar residential areas in the Caribbean.
Climate change may, among its many potential impacts, aggravate water shortages. Experts are predicting that rainfall in the eastern Caribbean will decline by 4 per cent in the coming years unless drastic cuts in greenhouse gas emissions occur.
Global warming is also likely to affect agriculture in the region. Bananas, a key crop, are very thirsty plants and are prone to Black Sigatoka disease under dry conditions.
An estimated 70 per cent of the Caribbean?s population lives in cities, towns and villages located in vulnerable low-lying coastal areas threatened by rising sea levels and increasing frequency and intensity of storms and hurricanes. In 2004, several of the Caribbean small island developing States experienced severe devastation, the loss of thousands of lives and millions of dollars in damages because of intense hurricanes.
Meanwhile, alien invasive species, transported to the region in ships? ballast waters or in imports such as horticultural products, may also threaten the existence of native and often unique plant and animal species found nowhere else on Earth.
The Dominican Republic, with an estimated 186 known alien species, has the highest number of invaders followed by Puerto Rico, 182; the Bahamas, 159; and Jamaica, 102.
Alien species may increase the number of native or endemic species already threatened with extinction as a result of habitat loss, deforestation and the clearance of land for farming and urbanization.
Currently Jamaica has, at 254, the highest number of threatened animal and plant species in the Caribbean followed by Cuba with 225.
These are among the findings from a series of reports released by UNEP on small island developing States around the world.
The reports, an international effort involving scientists and collaborating centers across the world, cover the Caribbean and the Pacific, Atlantic and Indian Ocean and small island developing States.