Indonesia, Malaysia, the Philippines, Timor Leste and Papua New Guinea have set new plans to protect the Coral Triangle - a 5.5 million square kilometer area that holds the largest biodiversity in the oceans. Scientists consider it to be the marine equivalent of the Amazon rain forest, and say it is crucial for preserving life in the world's oceans. The agreement was reached in Manado, Indonesia.

In the area of the sea area wedged between Indonesia and the Solomon Islands lies an extraordinarily rich sample of biodiversity: three quarters of all coral species live here, a third of the world's fish, half of its mangroves - all precious ecosystems.

Coral Triangle is essential to humans

Nancy Knowlton, a leading expert in marine life with Smithsonian Institute in Washington, says humans could not live without this region, called the Coral Triangle.

"It's by far the most diverse part of the ocean. So if you had to protect any one part of the oceans you'd protect this place. Things that are here can move out of the Coral Triangle to the Great Barrier Reef or the coasts of Japan, or further east into the Pacific Ocean. So in that sense you can think of it as a nursery, where so much of the diversity of the world's oceans is concentrated, said Knowlton.

The national park of Bunaken, near Manado in northern Indonesia, lies in the heart of the Coral Triangle.

Early one recent morning, several small boats rock gently on the turquoise water, each with a few scuba divers getting ready to jump in to admire some of the most beautiful coral reefs on the planet.

"OK? This place, we call it Mandarin; this is another wall dive. I hope we can find sharks here, because most of the time we find sharks, eagle rays, also Napoleon (wrasse fish). Ok?" a diving instructor explains.

Below the surface, schools of fishes dance in the divers' bubbles. The coral reefs flash like green, yellow and red flowers in an amazing chorus of colors.

Many depend on coral reef

Places like the Bunaken national park directly support the livelihood of more than 100 million people throughout the Coral Triangle. This part of the world's oceans also feeds millions outside of its borders, as it nurses young fish that end up in plates all around the world.

At the end of a dive, David McCauley, a climate change specialist from the Asian Development Bank, says that this area is endangered. Pollution, development on land, and overfishing cause problems. But even natural events, such as the El Nino weather pattern of warming ocean currents, can be a threat.

"There are some shifts that are consistent with what is associated with climate change, he said. There was a El Nino event here in 1997-98, where temperatures increased substantially, and there was some coral bleaching at that time. And there are a lot of concerns that the next El Nino may be even stronger. But in the longer haul we're quite worried about the ocean chemistry, the temperature, and how that will affect the marine organisms."

The environmental organization WWF just released a study that paints a bleak picture of what will happen to the Coral Triangle if nothing is done to protect it. Ove Hoegh-Guldberg led the research team. He says that negotiations to curb carbon emissions, to be held in Copenhagen next December, will be crucial for its survival.

"When you take the stresses of overfishing, pollution and things, you pile those up with climate change, things disappear very quickly. So if I go back to our world where we haven't been very careful with these reefs, and now I imagine that our leaders have let us down in Copenhagen, what we'd see here is that the restaurant where we sit here could be under water; we'd see a reef that's devastated, we'd see no mangrove. So at the end of the day, it'd be a largely unlivable world, he said.

Rising temperatures pose threat

Most climate researchers say the emission of so-called greenhouse gases, many of them burning fuels such as oil and coal, contribute to warming global temperatures. They say those rising temperatures will cause severe weather disturbances that could threaten crops, animal life and cities around the world.

Nancy Knowlton says time is running short on efforts to reduce global warming.

"I'm not, personally, comfortable with the idea of destroying one quarter of the diversity in the planet. That qualifies as a mass extinction, and we've had only five mass extinctions in the planet in, you know, hundreds of millions of years. For humans to create a sixth mass extinction, that's a pretty serious responsibility for us to take on, she said.

During the World Oceans conference that wrapped up this week in Manado, delegates stressed the importance of oceans in fighting climate change. But they say the conference was only a first step. Next stop is Copenhagen summit, where governments hope to reach an agreement to drastically curb carbon emissions.