Warmer than usual ocean temperatures have caused as much as 90 percent of the coral reefs in the shallow waters around Christmas Island to turn into an eerie, ghostly white.

"This is about as bad as it gets bleaching-wise," said Jean-Paul Hobbs, a research fellow at Curtain University in Western Australia.  He's part of a team of divers who have been surveying the island's reefs as part of a national effort to determine how bad this bleaching event is for the eco-system.

"The coral extends down 60 to 70 meters and there is bleaching all the way down to those depths," said Hobbs.  "It indicates what we are seeing is a widespread event, rather than the patchy event they had in the past."

This is being caused by rising water temperatures, the same problem for the Great Barrier Reef and other reefs around the world.  The sea around Christmas Island was about 31 C degrees in recent weeks, instead of the usual 28 C degrees for this time of year.  When the water gets too hot like this, coral expels the tiny organisms that give it its color.  Bleaching isn't necessarily a death sentence, but it does take these ecosystems more time to recover than it does to bleach.

"We are certainly very hopeful at this stage that it is just a bleaching event, and that the algae come back into the reef," said Linda Cash from the Christmas Island Tourism Association, noting that it did happen after the 1998 bleaching.  "We did have fantastic recovery back then," she added, "all we can hope for is the same result this time."