The Decline of Reef Predators Could Mean Disaster For Reefs

Science Features Reef Sharks
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The Decline of Reef Predators Could Mean Disaster For Reefs

A trip to see coral reefs isn’t complete without sighting some big predators like sharks and barracuda. Sadly, up to 90 percent of reef predators have disappeared from the Caribbean due to overfishing, disrupting the delicately balanced ecosystem and leaving visitors disappointed.

John Bruno, a marine biologist from the University of North Carolina at Chapel Hill, and Abel Valdivia, a study co-author, studied the reefs and released their findings in the journal Science Advances. Bruno explained that the loss of these predators not only means a decline in tourism for the islands, but also a dramatic increase in small fish that then in-turn put added stress on the environment, as is common when a deer population grows too quickly and vegetation suffers.

The team surveyed 39 reefs across the Bahamas, Cuba, Florida, Mexico and Belize in order to determine how much fish had been lost and to study the differences between over-fished and healthy reefs. Reefs that once teemed with life and were balanced are now suffering and dying as a result of people’s impact.

However, the study also revealed that if predatory fish were reintroduced to certain reefs, known as supersites, they could be revitalized and restored back to their original state.

“On land, a supersite would be a national park like Yellowstone, which naturally supports an abundance of varied wildlife and has been protected by the federal government,” said Bruno. These sites are prime locations for establishing protected areas where fish that are typically targeted for fishing, like grouper, can be reintroduced and the reefs can be saved.

Enforcing stronger protections on current reserves and establishing new protected sites will help not only the environment, but also tourism. “There is a massive economic incentive to restore and protect sharks and other top predators on coral reefs,” said Valdivia.

The researchers did not expect to find promising solutions when they began studying the decline in large predators, but this ray of hope could save the beautiful reefs and restore the predators to healthy levels.

Top photo by greyloch, CC BY-SA 2.0

Lauren Leising is a freelance writer based in Athens, Georgia.