Warming Is Causing Global Coral Bleaching

The National Oceanic and Atmospheric Administration (NOAA), the federal agency focused on the condition of the oceans and the atmosphere, and reef scientists from a number of countries said it is a global coral bleaching event, which is going to get worse.

Since the early 1980s the world has lost roughly half of its coral reefs.

Bleaching is a phenomenon that turns corals white or fades their colours.

The Great Barrier Reef in Australia, which at about the size of Italy is one of the most iconic reefs in the world, is not yet feeling the effects of this bleaching event, but it may soon.

The bleaching has hit reefs in the Pacific, Atlantic and Caribbean.

The coral bleaching event started in Guam in 2014 and reached Hawaii, the tropical Pacific and the Indian oceans.

Warm water causes bleaching and ocean temperatures are at record highs, partly because of manmade global warming and partly because of the El Nino, an occasional warming of the central Pacific that changes weather worldwide, Eakin said.

Corals reefs are suffering a severe underwater heat wave this year for the third time on record, including a mysterious warm patch in the Pacific known as “The Blob”, scientists said on Thursday.

On a global level, this event is expected to affect more than 38% of the world’s coral reefs by the end of 2015 and kill more than 4,630 square miles (more than 12,000 square kilometers) of reefs, according to NOAA.

In August, global average ocean temperatures were the warmest they had ever been for any month since record-keeping began in 1880. Hoegh-Guldberg said the current event was directly in line with predictions he made in 1999 that continued global temperature rise would lead to the complete loss of coral reefs by the middle of this century.

Hoegh-Guldberg said he had personally observed the first signs of bleaching on Australia’s Great Barrier Reef in the past fortnight, months before the warm season begins. Water temperatures are being driven further by a separate natural warm-water mass dubbed the Pacific Blob. Local marine scientists, volunteers and others – under the umbrella of monitoring groups such as Reef Check in Marina del Rey, California – then go out to inspect the conditions where bleaching may be happening.

On land, the “equivalent would be tropical forests turning white … and then dying”, said Richard Vevers, Executive Director of XL Catlin Seaview Survey which also contributed to the report. Among other technologies, it uses a high-resolution camera attached to an underwater scooter to quickly compile 360-degree images of reefs. “We’re not going to let this one slip by”, he adds. In a bay off the island of Oahu in Hawaii, a few corals that experienced bleaching in 2014 surprisingly managed to reproduce this year, even with back-to-back bleachings.

The Barrier Reef – the world’s biggest coral reef ecosystem – is already struggling from the threat of climate change, as well as farming run-off, development and the coral-eating crown-of-thorns starfish.

“Coral bleaching doesn’t necessarily mean that corals are going to die”, he said. And other factors, such as ocean acidification, are also stressing corals to the point that decades from now, reef communities will look and function much differently than they do today, says Cheryl Logan, a marine biologist at California State University, Monterey Bay, in Seaside.