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Undersea Photographers Bring ‘Coral Bleaching’ to the Surface

Image: Bleached coral

Bleached coral at Lisianski Island in the Papahanaumokuakea Marine National Monument, in 2014. The pale coral is bleached due to thermal stress, while the lavender-colored coral is healthy. Courtney Couch / NOAA - HIMB via AP

KANEOHE BAY, OAHU – "Divers, are you both ready? One, two, three, up!"

With a tug and a splash, the wetsuit-clad XL Catlin Seaview Survey dive team hoists the black, torpedo-shaped SVII, an undersea camera, into the warm, cobalt water of Kaneohe Bay, off the east coast of the Hawaiian island of Oahu.

Richard Vevers, an underwater photographer and the project's director, watches from the dive boat as two scuba divers grab hold of the sleek camera and its motorized scooter and plunge into the water towards the coral reef below.

Climate Change Scientists Take You On Virtual Scuba Dive in Hawaii 1:11

Their mission: to survey the world’s reefs and establish a baseline of coral health that can be monitored for changes as warming oceans threaten the colorful underwater ecosystems. When ocean temperatures rise to a level too warm, the coral expel the algae living in their tissues, causing it to turn completely white, in a process called "coral bleaching." If the temperatures do not decrease in a short period of time, the coral will die.

The XL Catlin Seaview Survey –- sponsored by the insurance company XL Catlin -– has already taken 750,000 images in the waters off 26 countries over the past three years using the SVII camera. The SVII is actually three cameras enclosed in a waterproof housing. Its wide angle lenses allow it to capture photographs of corals and then geolocate each photo using GPS technology.

Rising Temps Threaten Existence of World’s Coral Reefs and Their Underwater Beauty 1:52

The team's expedition in Hawaii is particularly urgent, because the coral here faces a 90 percent chance of "bleaching" this year, said Ruth Gates, an expert on coral bleaching from the Hawaii Institute of Marine Biology.

Thirty-five feet beneath the ocean's surface, Vevers spots signs that the health of the coral is declining.

"This coral here is really starting to bleach," Vevers said, pointing to a large patch of white skeleton. "And you can see over here, this is all dead."

A member of the XL Catlin Seaview Survey investigates the health of the coral reef in Kaneohe Bay, Oahu, where warming ocean temperatures are already causing the coral to lose their living tissues and die in a process called 'coral bleaching.' Bill Paris/NBC News / Bill Paris/NBC News

Often mistaken for rocks, corals are actually colonial animals. Tiny coral polyps construct hard shells for themselves that build up and form the familiar structure of a coral reef.

"We're surrounded by animals,” Vevers said while diving among the twisting tufts of brown, green, and white coral. “These creatures, some of them are really, really old, and they've been here just happily for centuries."

Gates says ocean temperatures in Kaneohe Bay are already much higher than normal, posing a huge threat to coral. Typically, waters don't warm to dangerous levels until late September.

"The temperature is so high so early, and people are reporting coral bleaching now here in August,” Gates said.

"We've lost about fifty percent of coral reefs worldwide, and we know further change is coming," Vevers said. "Because the base temperature of the ocean has risen over the last few decades, they can no longer cope with these peaks in temperature, and that's where we're seeing mass die off of coral."

And the situation could soon get worse.

‘We have to make sure we keep reefs healthy’

Read More: Severe Coral Bleaching Spotted Near Hawaii's Oahu, Scientists Say

A section of warm water off the Pacific Ocean nicknamed "the Blob" by marine scientists coupled with the warming conditions of El Ninoare expected to further raise ocean temperatures -– up to 90 degrees Fahrenheit. And, what's worse, according to Gates, the warm temperatures –- unbearably warm for coral –- could persist for up to a month.

Gates calls this "a mixture for disaster." The world's coral reefs are home to enormous biodiversity. An estimated 25 percent of all marine species rely on coral reefs. Also, the structure of coral reef protects the land masses behind them from storms.

"Without that structure," said Gates, big Pacific storms will "barrel straight into the land."

In addition to the coastal protection they offer, coral reefs also carry huge value as tourism and recreation sites –- to the tune of more than $30 billion worldwide, according to NOAA.

XL Catlin hopes to shed light on what goes on below the waves through its partnership with NOAA and Google –- bringing a virtual dive to anyone with a computer or smartphone by uploading their geotracked images to Google Street View.

"We're trying to bring these images of the special treasures under the water to the public, for them to see for themselves these special gardens," said Malia Chow of NOAA's Hawaiian Islands Humpback Whale National Sanctuary.

At the end of the dive, XL Catlin dive team member Christophe Bailhache removes his scuba gear and covers the three lenses on the SVII camera. He loves speeding the custom-made SVII along the coral reefs.

"You never know what's around the corner, right?" XL Catlin dive team member Christophe Bailhache said, with his distinctive French accent. "You can't predict what you're going to see. And we're very lucky and privileged to be in this position to really explore environments that nobody has really ever explored before."