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Bali coral reefs thriving with low-voltage assist

THURSDAY, DEC. 6, 2007

PEMUTERAN BAY, Indonesia – Just a few years ago, the lush coral reefs off Bali island 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, the coral restoration project illustrates the creative ways scientists are trying to fight the ill effects of global warming.

The project – dubbed Bio-Rock – is the brainchild of scientist Thomas Goreau and the late architect Wolf Hilbertz. The two have set up similar structures in some 20 countries, but the Bali experiment is the most extensive.

Goreau said the Pemuteran reefs off Bali’s northwestern shore were under serious assault by 1998, victims of rising temperatures and aggressive fishing methods by impoverished islanders, such as stunning fish with cyanide poison.

“Under these conditions, traditional (revival) methods fail,” explained Goreau, who is in Bali presenting his research at the U.N.-led conference. “Our method is the only one that speeds coral growth.”

Some say the effort is severely limited.

Rod Salm, coral reef specialist with the Nature Conservancy, said while the method may be useful in bringing small areas of damaged coral back to life, it has very limited application in vast areas.

“The extent of bleaching … is just too big,” Salm said. “The scale is enormous, and the cost is prohibitive.”

Others note the Bali project is mostly dependent on traditionally generated electricity, a power source that itself contributes to global warming. Goreau himself concedes it has yet to attract significant financial backing.

Nonetheless, 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, if somewhat unorthodox.

It has long been known that coral that breaks off the reef can be salvaged and restored if it can somehow be reattached.

Goreau’s Bali project has constructed metal frames and submerged them in the bay. When hooked up to a low-voltage energy source on the shore, limestone – a building block of reefs – naturally gathers on the metal. Workers then salvage coral that has broken from damaged reefs and affix it to the structure.


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