Caribbean coral reefs face collapse

A pair of French angelfish enjoy the coral reef in the Caribbean Sea. Photograph: Marcus Mays for the Guardian

Source: The Guardian

Caribbean coral reefs – which make up one of the world’s most colourful, vivid and productive ecosystems – are on the verge of collapse, with less than 10% of the reef area showing live coral cover.

With so little growth left, the reefs are in danger of utter devastation unless urgent action is taken, conservationists warned. They said the drastic loss was the result of severe environmental problems, including over-exploitation, pollution from agricultural run-off and other sources, and climate change.

The decline of the reefs has been rapid: in the 1970s, more than 50% showed live coral cover, compared with 8% in the newly completed survey. The scientists who carried it out warned there was no sign of the rate of coral death slowing.

However, there are good news abour coral reefs too. Some Caribbean reef ecosystems are relatively intact compared to average conditions in the region. For example, many reefs in the Netherlands Antilles and Cayman Islands have 30 % or more live coral cover, little macroalgae, and a moderate (albeit strongly depleted) abundance of fish. In contrast, reefs in Jamaica and the US Virgin Islands have well below 10% live coral cover, abundant  macroalgae, and virtually no fish larger than a few cm.

The causes of these regional differences in reef conditions are not well understood beyond the obvious role of human exploitation and disturbance. Caribbean reefs with the highest surviving coral cover and least macroalgae tend to be characterized  by little land`based pollution, some degree of fisheries regulations and enforcement, moderate economic prosperity, and lower frequency of hurricanes, coral bleaching,  and disease.  Unraveling the potential interactive role of these and other factors is a  major goal of our study once all the necessary data are available.

Read more