London: Many of the Caribbean`s coral reefs could vanish in the next 20 years, according to a new report which found that healthy coral reefs have declined by about 50 per cent in the past four decades.
The report, published by the International Union for the Conservation of Nature (IUCN), looked at data collected between 1970 and 2012 from 90 reef habitats.
The results show that the Caribbean corals have declined by more than 50 per cent since the 1970s.
The report, which was also authored by the Global Coral Reef Monitoring Network, found that many reefs in the Caribbean were undergoing a dramatic transformation - changing from colourful realms to barren habitats, covered in slimy algae, `BBC News` reported.
Loss of some of the reefs` key inhabitants is mainly responsible for this, researchers said.
In the 1980s, a disease wiped out a large number of sea urchins. While fishing on the reefs has also caused parrotfish to plummet. Both of these creatures graze on reefs, and without them, algal species take over.
"We saw that reefs with no grazers ended up getting smothered by algae. And after a period of time they see a significant or even complete collapse of the reef area," said Carl Gustaf Lundin, director of IUCN`s Global Marine and Polar Programme.
He said that if no action was taken, the outlook for Caribbean corals would be bleak.
"If we do nothing, I`m afraid the most likely scenario is that we will continue the slippery slope to slime. We`ll lose a tremendous amount of coral cover and we`ll end up with algal reefs with a much lower diversity of species," Lundin said.
The report found evidence that damaged reefs could be revived if they were protected.