Caribbean Coral Reefs Are Mostly Dead

The coral reefs of the Caribbean are mostly wiped out, according to a new report from a major conservation group. Scientists have found that the reefs have about 8% of live coral coverage, down from about 50% to 60% in the 1970s, reports National Geographic. Some main culprits cited by the International Union for Conservation of Nature are overfishing, human sewage, and warming seas, notes NBC News. "It's a dire picture," says an IUCN official.

The downslide began in the 1970s, when scores of sea urchins got wiped out, likely from disease. The creatures are vital to coral because they eat algae and grasses that have now overwhelmed the reefs. Parrotfish and and surgeonfish also keep the vegetation in check, but overfishing has reduced their populations. Meanwhile, warmer waters have forced out beneficial algae that prevent the reefs from bleaching and dying. “The Caribbean system is one of first systems to experience collapse," says a researcher. "It’s something that will happen across the globe if human use of coral reefs continues as it is.” (More global warming stories.)