Gulf corals adapt to warmer water, but still in peril

Erika Solomon PlanetArk 15 Nov 10;

Twenty years ago, divers in Dubai could swim through coral gardens teeming with brightly-colored fish and sea turtles. Today, says marine biologist Tom Goreau, dead reefs stand like gravestones for an underwater ghost town.

In the United Arab Emirates, some of the world's glitziest building projects, such as the opulent homes on one of Dubai's manmade palm-shaped islands, sit on these coral cemeteries.

"The best reefs were simply dumped on," said Goreau, who heads the U.S.-based Global Coral Reef Alliance. "Those areas that were supposed to have been protected areas were peddled off to developers. They're gone, wiped out."

Surviving reefs contend with desalination plants, necessary for supplying fresh water to the desert countries along the Gulf coast. The plants spew hot brine and chemicals into the sea, warming their surrounding waters and increasing salinity.

Twenty percent of the world's reefs are damaged beyond repair. Scientists are uncertain about what proportion of the Gulf's reefs have died. A Kuwaiti diving team recently reported that 90 percent of the coral off Kuwait's coast was dead or severely stressed. Qatar has also seen dramatic coral death.

Scientists worry pollution and construction continues at a rate that could kill Gulf reefs, which had proven resistant to rising temperatures and increased ocean salinity.

Coral reefs support a third of the Gulf's fish populations -- and local economies.

"We don't protect corals just because they're beautiful," said Rita Bento, marine biologist for the Emirates Diving Association. "Corals are a source of food, fishermen go there to fish. Tourism also -- places with good reefs that are protected have economic growth. We have a lot to gain from them."

The UAE is growing more aware of climate threats, adding government environment advisers to approve coastal construction plans. Abu Dhabi is sponsoring the development of what it calls the first zero-emissions city, Masdar.

Overfishing is another problem, but scientists say damage to reefs, where fish feed and breed, may also be behind what Dubai fishermen say is a 20 percent drop in their catch since 1990.

"It's not like it was years back. There were a lot of fish and it was so cheap," said one fisherman, dumping baskets of brightly striped fish off his tiny motor boat for market.

RED TIDE

Hamad al-Roomy, general manager of the Dubai Fishermen's Cooperative, says in 2008 Gulf waters were invaded by a red tide, or harmful algae bloom, often caused by a sudden temperature change.

"It hit like a nuclear bomb that kills everything around it," he said. "You could see the red tide coming. The fish were trying to escape. They'd just jump right onto the beach."

Red tides soak up oxygen, suffocating fish. Hundreds of thousands of fish were killed in a single day. Months later, residual algae killed swathes of coral on the UAE's east coast.

Some scientists think red tides could become more common due to the warming of Gulf seawater, which is occurring faster than anywhere else in the world, probably accelerated by pollution.

Gulf Arab states have some of the world's highest per capita carbon emissions. World Bank and other data from 2006 and 2007 shows Qatar topping the table.

Pollutants can take years to be flushed out of the Gulf, which is almost entirely sealed from the wider ocean except at the narrow Strait of Hormuz, through which passes 40 percent of the world's seaborne oil.

SOURCE OF HOPE

But scientists say it is not the amount of coral death in the Gulf that surprises them, it's how much has survived.

Most corals cannot live in temperatures above 28 degrees Celsius (82 Fahrenheit), says Thabit Abdelsalaam, of the Abu Dhabi government's Environmental Agency.

"Our corals live and survive at 37 degrees centigrade," he said. "That could be a source of hope around the world."

The Gulf differs from most other seas where coral is found because at only 20,000 years old it is an evolutionary newcomer.

"Corals haven't had time to adapt into new species... but here, they've already adapted to high temperatures," says Keith Wilson of the Emirates Marine Environmental Group.

Researchers see a chance to learn how these corals adapted and to determine if this could be repeated elsewhere.

"This is an area where we can travel to the future and see how climate change will affect things," Bento said. "I wish I had more answers for you, but we don't have enough research."

Curbing pollution will not come easy in Gulf countries like the UAE, where oil money has built glittering villas and skyscrapers to replace the modest palm-frond homes of earlier generations.

Growth in the Gulf means more desalination. The UAE alone produces 9 million cubic meters of water daily and is planning to build six more plants to add another 4 million cubic meters.

"We can't stop development," said Abdelsalaam. "But we can make sure there's a balance between development and preservation of the environment."

Graduate student Richard Wagner carried out a study on how UAE residents view the threat to coral reefs. Most do not care.

"I told them that if the reefs die, most of their fish would die. They would say: 'we can just import more'."

(Editing by Alistair Lyon and Janet Lawrence)