MANADO, Indonesia - Around 100 million people risk losing their homes and livelihoods unless drastic steps are taken to protect Southeast Asia's coral reefs, which could be wiped out in coming decades because of climate change, a report said Wednesday.
The Coral Triangle - which spans Indonesia, the Philippines, Malaysia, Papua New Guinea, the Solomon Islands and East Timor - accounts for a third of the world's coral reefs and 35 per cent of coral reef fish species.
If carbon emissions are not cut by 25 per cent to 40 per cent by the year 2020, higher ocean temperatures could kill off vast marine ecosystems and half the fish in them, according to the World Wildlife Fund, which warned that 100 million people earning a living off the sea could be forced to leave inundated coastlines and find new jobs.
The group, which presented its 220-page study at the World Ocean Conference, cited 300 published scientific studies and 20 climate change experts.
"Decisive action must be taken immediately, or a major crisis will develop," the report said.
"Hundreds of thousands of unique species, entire communities and societies will be in jeopardy," it said.
Scientists have long warned that higher temperatures will melt polar ice and cause sea levels to rise, wiping out island communities and coastal ecosystems. Increasing carbon dioxide is also making oceans increasingly acidic, eroding sea shells, bleaching coral and killing other marine life.
But many questions remain about oceans - which can also play an important part in absorbing carbon - partly because the technology to study them is relatively new.
"We are looking to promote better understanding of the role of the ocean in the climate system," said Mary Glackin, U.S. deputy undersecretary for oceans and atmosphere. "It's really a web of life. So you need to be concerned about the very smallest thing up to the very high predators."
"The acidity that will be impacting some of those species could really have ripple-through effects," she added.
Fish living in the coral reefs, mangroves and sea grass ecosystems in Southeast Asia generate $3 billion US in annual income through commercial fishing, provide coastal protection from high waves and give food security to millions of the world's poorest families.
In addition to climate change, marine ecosystems are being eroded by pollution, declining water quality, overfishing and destructive fishing techniques.
Indonesia, the world's largest archipelago, said Wednesday it wasn't going to stand by and wait for disaster.
It officially launched a new, protected marine park in the Coral Triangle with a unique and varied ecosystem that is considered to be especially resilient to rising sea temperatures.
The park, an area about the size of the Netherlands, is a major migratory corridor and home to 14 whale species, as well as dolphins, dugongs, manta rays and sea turtles. It also has a high concentration of iridescent coral, fish, crustaceans, mollusks and plants.
"If well managed, this park has the capability to support sustainable fisheries and to ensure food security" for up to two million people in the region, said Minister of Marine Affairs and Fisheries Freddy Numberi.
The five-day oceans' conference in Manado is aimed at shaping scientific debate about the role of oceans ahead of a United Nations climate change meeting in Copenhagen, Denmark, in December.
That meeting will discuss a successor to the Kyoto Protocol, which expires in 2012.