Climate change has been blamed for the rapid decrease in coral cover in the Caribbean over the past few decades. But new research suggests that the impacts of pollution and overfishing may have been underrated. This is good news, experts say, because these problems are easier to address and reverse.
Climate change threatens coral reefs because ocean acidification restricts coral growth and extreme heat events can cause coral bleaching. But, a three-year multi-institutional report found that the biggest driver of reef death in the Caribbean was unchecked seaweed.
Nine percent of the world’s coral reefs are in the Caribbean. These ecosystems are environmentally and economically valuable. They are home to a breathtaking diversity of life, and they generate more than three billion dollars annually from tourism and fisheries.
But they have been disappearing rapidly – with a 50 percent decline in living corals since the 1970s. This trend has been linked to the loss of seaweed-eating species like parrot fish and sea urchins. Without these animals, uncontrolled seaweed growth can smother and kill coral.
Sea urchin populations have taken a hit due to disease. And parrot fish have become virtually extinct in areas due to overfishing. Some of the greatest coral declines in the Caribbean have occurred where parrot fish are unprotected.
The good news is, in areas that have restricted or banned harmful fishing practices, coral has begun to rebound. If the Caribbean’s treasured reefs are to be resilient in the face of climate change, swift action needs to be taken to ensure the survival of parrot fish and other seaweed-eating animals.
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Overfishing and Pollution Kill More Corals than Climate Change
Photo, posted March 27, 2011, courtesy of USFWS – Pacific Region via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio, with script contribution from the Cary Institute of Ecosystem Studies.