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.