Global warming effects coral reefs:
Global Warming Has Devastating Effect on Coral Reefs, Study Shows
Sean Markey for National Geographic News
May 16, 2006
Eight years after warming seas caused the worst coral die-off on record, coral reefs in the Indian Ocean are still unable to recover, biologists say.
Many reefs have been reduced to rubble, a collapse that has deprived fish of food and shelter.
As a result, fish diversity has tumbled by half in some areas, say authors of the first long-term study of the effects of warming-caused bleaching on coral reefs and fish.
The study focused on reefs near Africa's Seychelles islands, north of Madagascar (see Seychelles map), which sustained heavy losses from bleaching in 1998.
"The outlook for recovery is quite bleak for the Seychelles," said lead study author Nicholas Graham, a tropical marine biologist at England's University of Newcastle Upon Tyne.
The study, in today's Proceedings of the National Academy of Sciences, predicts that isolated reef ecosystems like that around the Seychelles will suffer the most from global warming-caused bleaching events.
Warming Oceans
Small but prolonged rises in sea temperature force coral colonies to expel their symbiotic, food-producing algae, a process known as bleaching.
While the dying reefs, which turn ghostly white, can recover from such events, many do not.
In 1998 an El Niño weather pattern sparked the worst coral-bleaching event ever observed.
"Over 16 percent of the world's reefs … were lost in that one year," said Graham, part of a team that recently received an unrelated research grant from the National Geographic Society Committee for Research and Exploration. (National Geographic News is a part of the National Geographic Society.)
"It was a huge event."
Low-Voltage Electricity Reviving Sick Coral Reef
Wednesday, December 05, 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 and scooping them up with nets.
"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 that need protection.
"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 method 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.
What Goreau's Bali project has done is to construct metal frames, often in the shape of domes or greenhouses, and submerge 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.
Goreau and his supporters say the electricity spurs the weakened coral to revival and greater growth.
"When they get the juice, they are not as stressed," said Rani Morrow-Wuigk, an Australian-German woman who rents bungalows on the beach and has supported efforts to save the reefs for years.
And indeed, the coral on the structures appear vibrant, and supporters say they have rebounded with impressive vigor. The coral in Pemuteran teems with clownfish, damselfish and other colorful tropical animals.
Funding, however, is a major problem. There are some 40 metal structures growing coral in Pemuteran Bay and about 100 cables laid to feed them with electricity, but only about a third of the wires are working because of maintenance problems and the cost of running them, said Morrow-Wuigk.
The electrification program 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 other people 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 in the area.
Brown has participated in Goreau's projects, and won funding from the Australian government to set up a Bio-Rock structure electrified by solar panels fixed on a floating off-shore platform.
Brown has also used seed-money from Canberra to establish the Reef Gardeners of Pemuteran, which trains islanders to dive, maintain the solar-paneled coral structure and clean the reefs of harmful animals.
Kadek Darma, 25, a Balinese who has worked with Brown for two years, said the advantages of the corals to the local economy 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."
Adappted from: http://www.globalcoral.org/
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So please, save coral reefs!
