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Over-fishing seen as culprit in Fiji coral collapse

Tuesday, April 16, 2013 - 02:02

April 16 - Researchers from Georgia Tech University say a deadly seaweed is destroying coral reefs off Fiji because of over-fishing. After studying hours of video footage, the researchers found that the fish species which historically eat the seaweed have largely disappeared, allowing the toxic plant to spread and overwhelm the coral. Ben Gruber has more.

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Sitting just off the coast, outside the marine protected area in Fiji, this once thriving coral reef is dying. It has been overwhelmed by a toxic seaweed species, and has little chance of survival. It's an increasingly common occurrence in the area, according to environmental biologist Mark Hay. He wanted to know why it was happening so with his team from Georgia Tech University, he travelled to Fiji to investigate. The researchers found that in protected zones with diverse populations of fish, the corals where healthy. But where fewer fish species existed, the deadly seaweed had taken over. (SOUNDBITE) (English) MARK HAY, PROFESSOR OF ENVIRONMENTAL BIOLOGY, GEORGIA TECH, SAYING: "The two most toxic seaweeds to corals there was only one fish that ate each of those. One ate number one and one ate number two. Nobody else touched them. And for one of the really toxic ones, it makes these cyto-toxic compounds that kills cells, 28 species of the fish just wouldn't touch that. We never saw them take a bite." Hay says that despite centuries of sustainable fishing, increased demand from expanding Fijian communities has led to overfishing of certain species. He says local fishermen are aware of the problem. (SOUNDBITE) (English) MARK HAY, PROFESSOR OF ENVIRONMENTAL BIOLOGY, GEORGIA TECH, SAYING: "Our hope is that we can come up with more new ways to say 'you can eat, you can harvest fish from the ocean, your children don't have to starve. But if you do it this way it is sustainable, and if you leave these particular ones alone you will grow back more reef and attract more fish and have sort of a living supermarket off shore." Hay says local communities are eager to reverse the decline and maintain the health of their reef ecosystems by fishing more carefully. But he says the global problem of reef destruction requires a much broader solution. He says that ocean acidification, another coral killer, has increased more than 25 percent in the past 100 years because of climate change and that more than half of Earth's coral reefs are threatened by extinction.