From Frontier

A recent report describing a three year collaboration between the International

Union for Conservation of Nature (IUCN), the United Nations Environment Programme (UNEP) and the Global Coral Reef Monitoring Network (GCRMN) revealed that the majority of the Caribbean’s coral reefs may disappear within the next 20 years.

This shocking news was the result of an extensive study which involved 90 experts, 90 locations and the analysis of more than 35,000 surveys. Analysing data from 1970 to 2012, the study showed that Caribbean coral reefs have declined by more than 50%. At this rate, the next 20 years could see the complete disappearance of these reefs. The Caribbean is currently home to 9% of the world’s coral reefs. These areas rival the biodiversity of tropical rainforests and generate more than US$ 3 billion annually from tourism and fisheries with 43 million people depending on this revenue.

Coral reef degradation has long been attributed to climate change which leads to ocean acidification, coral bleaching and disease. However, this current report shows that the main cause of coral degradation in the Caribbean is actually the loss of grazers, in particular sea urchins and parrotfish. These species feed on algae and when they are removed from the ecosystem, algal growth increases rapidly and smothers the reefs.

In 1983, an unidentified disease caused mass mortality of sea urchins in the Caribbean. Between 95 and 99% of the species Diadema antillarum, an important herbivore, was eliminated from the region and this was immediately followed by a 20% increase in algal biomass in just five days.

Coral reef degradation has long been attributed to climate change which leads to ocean acidification, coral bleaching and disease. However, this current report shows that the main cause of coral degradation in the Caribbean is actually the loss of grazers, in particular sea urchins and parrotfish. These species feed on algae and when they are removed from the ecosystem, algal growth increases rapidly and smothers the reefs. In 1983, an unidentified disease caused mass mortality of sea urchins in the Caribbean. Between 95 and 99% of the species Diadema antillarum, an important herbivore, was eliminated from the region and this was immediately followed by a 20% increase in algal biomass in just five days.

Intensive fishing throughout the Caribbean means that parrotfish are close to extinction in some areas. In addition to feeding on algae, parrotfish (along with other species such as angelfish) also feed on sponges. Research has shown that when these species are dramatically reduced by overfishing, the fast-growing palatable sponges they would usually feed on grow rapidly and start to dominate reefs. Increased competition with these sponges reduces endangered reef-building corals.

But all is not lost! These reefs can be saved if proper protection and management strategies are put in place. This includes restoring parrotfish populations and tackling overfishing and pollution. It is hoped that if the reefs can be restored, they will also become more resilient to future climate change. Jeremy Jackson, IUCN’s senior advisor on coral reefs, said: “Even if we could somehow make climate change disappear tomorrow, these reefs would continue their decline. We must immediately address the grazing problem for the reefs to stand any chance of surviving future climate shifts.”

Changes are already starting to be made. In Barbuda, all catches of parrotfish and grazing sea urchins are about to be banned and one-third of its coastal waters will be set aside as marine reserves. Carl Gustaf Lundin, Director of IUCN’s Global Marine and Polar Programme said: “This study brings some very encouraging news: the fate of Caribbean corals is not beyond our control and there are some very concrete steps that we can take to help them recover.

Frontier currently carries out important work monitoring coral reef health in Madagascar, Tanzania, Cambodia and Fiji. Alongside this, a new project is currently being set up and developed in Belize, within the Caribbean. This vital work will provide more information on the health of coral reefs in the Caribbean and play a key role in preserving these important habitats.

Do you want to get involved yourself? Read more about Frontier’s unique marine conservation programs and become a part of a team dedicated to protect the world’s coral reefs.

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IMAGES:

Image courtesy of Paul Asman and Jill Lenoble

Image courtesy of Je Norton

Image courtesy of JoshBerglund19

Image courtesy of Laszlo Ilyes

For more on this story go to: http://blog.frontiergap.com/blog/2014/8/14/caribbean-coral-catastrophe.html