Most coral reefs in the Caribbean Sea are likely to be gone in the next 20 years as a result of overfishing and pollution, a study by the International Council for the Conservation of Nature found.

The analysis shows that, since 1970, more than half of the Caribbean's coral has disappeared, according to The Guardian. Ninety experts measured around 100 Caribbean locations to come up with the analysis.

Despite the dire nature of the report, it also says that restoring key fish populations and reducing pollution could help the reefs make a full recovery, The Guardian reported.

"The rate at which the Caribbean corals have been declining is truly alarming," Carl Gustaf Lundin, director of IUCN's marine program, said, reports The Guardian. "But 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."

Those steps involve getting grazer species back into the ecosystem, the BBC reported. The study said that the key driver in the coral decline was the loss of the two main grazer species, the parrotfish and sea urchin.

Grazers are important to the reefs because they eat the algae that can suffocate corals. Overfishing and disease have been the primary causes of the loss of these two species in the Caribbean.

The report said that the reefs in the Caribbean that are the healthiest are those that have put protection in place for the Parrotfish, including the U.S. Flower Garden Banks, Bermuda and Bonaire, The Guardian reported.

The Caribbean is home to 9 percent of the world's coral, which spans 38 countries and is crucial to many economies, according to The Guardian. The reefs draw more than 43 million people and bring in about $3 billion annually, highlighting their importance to the region.

"We have been able to document a number of cases where we've seen recovery of degraded reefs, so that is very positive," Lundin said, reports the BBC. "It means we shouldn't give up hope."