PEMUTERAN BAY, Indonesia - A few years ago, the lush coral reefs off Bali were dying out, bleached by rising temperatures, blasted by dynamite fishing, and poisoned by cyanide. Now they are coming back, thanks to an unlikely remedy: electricity.
The coral is thriving on dozens of metal structures submerged in the bay and fed by cables that send low-voltage electricity, which conservationists say is reviving it and spurring greater growth.
As thousands of delegates, experts and activists debate climate at a conference that opened this week on Bali, coral restoration illustrates some of the creative ways scientists are trying to fight global warming's ill effects.
The project, dubbed Bio-Rock, is the brainchild of scientist Thomas Goreau and the late architect Wolf Hilbertz. The two set up similar structures in 20 or so countries, but the Bali experiment is the most extensive.
Goreau said the Pemuteran reefs off the Indonesian island's northwestern shore - a scuba-diving mecca - were under serious assault by 1998, victims of rising temperatures and aggressive fishing methods by impoverished islanders, such as stunning fish with cyanide and scooping them up with nets.
"Under these conditions, traditional [revival] methods fail," said Goreau, who is in Bali presenting his research at the conference. "Our method is the only one that speeds coral growth."
Some say the effort is very limited.
Rod Salm, a coral-reef specialist with the Nature Conservancy, said that while it may be useful in bringing small areas of damaged coral back to life, it has minimal application in the vast areas that need protection.
"The scale is enormous, and the cost is prohibitive," Salm said.
Others note that the Bali project depends largely on electricity generated by traditional means - methods that contribute to global warming.
Still, scientists agree that coral reefs are an especially valuable - and sensitive - global environmental asset. They provide shorelines with protection from tides and waves, and host a stunning diversity of plant and sea life.
Goreau's method for reviving coral is decidedly low-tech and unorthodox.
It has long been known that coral that breaks off a reef can be restored - if it can somehow be reattached.
The Bali project constructed metal frames, often in the shape of domes, and submerged them in the bay. When the frames are hooked up to a low-voltage energy source on the shore, limestone - a building block of reefs - naturally gathers. Workers then salvage coral that has broken off damaged reefs, and affix it to the structure.
Proponents say the electricity spurs weakened coral to greater growth.
"When they get the juice, they are not as stressed," explained Rani Morrow-Wuigk, an Australian-German woman who has supported efforts to save the reefs for years.
The coral on the structures appear vibrant, teeming with clownfish, damselfish, and other colorful sea life.
But funding is a big problem. There are about 40 metal structures growing coral in Pemuteran Bay and 100 cables laid to carry the electricity, but only one-third of the wires work, because of maintenance problems and the cost of running them, Morrow-Wuigk said.
Electrification is part of a wider effort in the bay to save the coral.
Chris Brown, an Australian diving instructor who has lived in Bali for 17 years, said he and others who are determined to save the reefs have had a long struggle driving away fishermen who use dynamite and other coral-destroying methods to maintain their livelihoods.
He said a key has been demonstrating to shoreline communities the benefits of coral-reef maintenance, such as growing fish stocks and jobs catering to tourists who come to dive.
Kadek Darma, 25, a Balinese who has worked with Brown for two years, said coral's advantages were obvious.
"They attract the tourists, and more tourists means more jobs," he said. "I hope we can all keep maintaining the reefs for our great-great grandchildren."