Study: Global Coral Crisis Is In Full Bloom
Coral reefs around the world are in bad shape these days. But a new research paper in the journal Science says their problems may be getting worse. The paper says as much as a third of the world's coral species may now be headed toward extinction, thanks to problems ranging from destructive fishing boats to ocean waters warmed by global climate change.
Coral experts say these reefs hold 25 percent of the world's marine species. That list includes sponges, lobsters, turtles, shrimp, sharks and commercially important fish. Philip Munday, a reef expert at Australia's James Cook University, says that's why coral reefs are often called "the rain forests of the ocean."
"It's quite stunning when you get into the water on a lovely clear day and you drop down onto [healthy] reef," says Munday. "There are fish everywhere, hundreds of thousands of fish, the sort of things you almost don't see anywhere else."
Unfortunately, reefs like those are few and far between these days. And Kent Carpenter, a reef expert at Virginia's Old Dominion University, says the problems faced by these important ecosystems may be worse than a lot of experts think they are. In a new paper, he reports that a third of the world's coral species are now declining toward extinction, partly owing to increased outbreaks of coral diseases. Corals that aren't killed off by these new diseases are recovering more slowly, he reports. Some are slowly overwhelmed by ugly gobs of algae.
"I have been on several coral reefs recently that have had large clumps of algae growing on the reefs themselves," he said. "And if you pull off the algae, you see that the coral underneath them has died, because it couldn't get any sunlight."
Carpenter says sights like those are easily as ugly as the image of a thriving reef is beautiful, adding that in his opinion a global coral crisis is now in full bloom.
"This is a whole ecosystem that we potentially could be losing," he said.
That's the central message in the paper Carpenter has just published in Science. He says he prepared it with the help of coral researchers affiliated with the International Union for Conservation of Nature, a nonprofit conservation group whose scientific work is widely thought to be definitive.
The coral researchers pored through records kept at field stations near coral reefs found all over the tropics. Carpenter says the result is a so-called coral "red list" that concludes that a third of the world's coral species may be declining toward extinction. He says the researchers found some evidence of a link between coral-killing diseases and warming ocean waters. He adds that it's possible that even bigger problems will emerge if emissions of global warming gases aren't reduced soon.
For example, he says ocean waters are becoming more acidic as they soak up carbon dioxide, the main global warming gas. And while there's evidence that coral reefs can find ways to adapt to waters warmed by global climate change, there's no proof that they can cope with more-acidic oceans.
"Obviously the overarching problem that has to be solved is the [buildup of man-made] carbon dioxide in the atmosphere," he said.
Carpenter's new paper drew a lot of attention at a coral reef conference held this week in Fort Lauderdale, Fla. The paper also drew support from a different report prepared by scientists with the National Oceanic and Atmospheric Administration. That paper concluded that a quarter of the coral reefs in U.S. waters were in poor condition.
There are some rays of hope in the new coral red list. For example, it appears to show that reefs in some parts of the far Pacific are now thriving in the warming waters. And Munday, the Australian reef expert, says research conducted near the Great Barrier Reef appeared to show that when a wounded coral reef is put off limits to commercial fishermen, large numbers of big fish fill the area in a few years.
"That gives us enormous hope that these populations ... can rebound if they're given the chance to do so," he says. Munday says these programs won't protect coral reefs from problems caused by global warming. But they might help buy the reefs a little extra time.
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RENEE MONTAGNE, Host:
You most likely have heard that coral reefs around the world are in bad shape these days. A new research says the situation is getting worse. As much as a third of the world's coral species now may be headed toward extinction.
Coral reef experts have been meeting all week in Florida to draw attention to this threat. NPR's John Nielsen has more on what they're saying.
JOHN NIELSEN: Coral reefs, like rain forests, hold an amazing range of plants and animals. In fact, according to biologist Philip Munday, these reefs hold a quarter of the species found in the world's oceans.
MONTAGNE: It's quite stunning when you get in the water on a lovely clear day and you drop down onto a reef, and there are just fish everywhere, hundreds of thousands of fish, the sort of things you almost don't see anywhere else.
NIELSEN: Munday's with James Cook University in Australia. He says reefs like these used to be commonplace in shallow waters all over the tropics. In addition to the fish, they featured sponges, lobsters, turtles, urchins, shrimp, anemones, you name it. Unfortunately, reefs like these are now few and far between.
Kent Carpenter is a reef expert at Old Dominion University in Virginia. Recently, he reviewed the status of 850 different coral species. What he found was that a third of them may be headed toward extinction.
Fishing boats have ruined some of the reefs, while others have been killed by diseases. Carpenter says reefs that don't die quickly are sometimes finished off by nasty-looking gobs of algae.
MONTAGNE: I've been on several coral reefs recently that have had large clumps of algae growing on the corals themselves, and if you pull off the algae, you see that the corals underneath them have died.
NIELSEN: Carpenter says that's a sight as ugly as the image of a thriving reef is beautiful.
MONTAGNE: It's heart-wrenching, and I guess I can't emphasize enough that this is a whole ecosystem that we could be potentially losing on the planet.
NIELSEN: That's the message in a so-called coral red list that's been published by Carpenter in the journal Science. Basically, it names the threat to the world's coral species. Researchers prepared it after poring through records kept by field biologists stationed all over the tropics.
The red list researchers found evidence that hints that coral diseases hit more frequently in waters warmed by manmade climate changes, and Carpenter says even bigger threats to coral species could emerge if emissions of global warming gases are not reduced soon.
For example, as the oceans soak up more carbon dioxide, they're becoming more acidic, says Carpenter, and while there is some evidence that coral reefs can find ways to adapt to rising temperatures...
MONTAGNE: There's no evidence at all that they can adapt to different pH or acidic regimes. Obviously the overarching problem that has to be solved is the carbon dioxide in the atmosphere.
NIELSEN: Twenty-seven-hundred coral reef experts met all week in Florida to talk about these problems. On Monday, scientists from the National Oceanic and Atmospheric Administration issued a report that seemed to echo some of Carpenter's findings. It concluded that a quarter of the reefs found in American waters were in poor condition. But reef scientists like Philip Munday say there are a few rays of hope here.
For example, the new coral red list seems to show that some Pacific reefs are finding ways to thrive in the warmer waters, and when fishermen were banned from all but ruined reefs in Australian waters, big fish seemed to show up out of nowhere
MONTAGNE: And that's just in a few years. So that gives us enormous hope that these populations of fish can rebound if they're given the chance to do so.
NIELSEN: At the least, he says, these changes could give the reefs a little more time. John Nielsen, NPR News, Washington. Transcript provided by NPR, Copyright National Public Radio.
