Coral reefs in the Caribbeans are rapidly degrading because of pollution and overfishing, and not due to climate change.

A new comprehensive study released by the Global Coral Reef Monitoring Network (GCRMN), the International Union for Conservation of Nature (IUCN) and the U.N. Environment Programme (UNEP) revealed coral cover in the Caribbean has dropped by over 50 per cent since the 1970s. And sadly, most of those coral reefs could vanish in the next two decades.

"With only about one-sixth of the original coral cover left, most Caribbean coral reefs may disappear in the next 20 years, primarily due to the loss of grazers in the region," the study undertaken by 90 coral experts said.

The culprit was the threats posed by fisheries, tourism and coastal development.

"Caribbean coral reefs and their associated resources will virtually disappear within just a few decades" unless immediate measures are done and implemented to curb the threat, the authors said.

"The rate at which the Caribbean corals have been declining is truly alarming," The Independent quoted Carl Lundin, director of the International Union for Conservation of Nature (IUCN), one of the groups behind the new study. "But this study brings some very encouraging news: the fate of Caribbean corals is not yet beyond our control and there are some very concrete steps that we can take to make them recover."

The study likewise took pains to explain that climate change had been wrongfully accused as the sole reason for the degradation of the coral reefs in the Caribbean.

"Climate change has long been thought to be the main culprit in coral degradation. While it does pose a serious threat by making oceans more acidic and causing bleaching, the report shows that the loss of parrotfish and sea urchins - the area's two main grazers - has, in fact, been the key driver of coral decline in the region."

"We know that these things will be more and more critical as time goes on and humanity burns more coal and oil and puts more CO2 into the atmosphere," Jeremy Jackson, lead author of the report and scientific director of GCRMN, said. "But when you look at the entire region, it's something else other than extreme heating events that has been a much more important driver of the lost corals."