Ranongga resident Hendrik Kegala points to a coral reef that was exposed when the small Solomon island was raised out of the water by an April 2, 2007, earthquake.

The long-term impact of the quake and a subsequent tsunami on the islands' coral reefs is uncertain.

The sudden rise of Ranongga is "going to be devastating to the coral that was uplifted," said Rick MacPherson of the Coral Reef Alliance in San Francisco.

But the shifting geography has opened up new areas in which corals can grow, he said. "There is some new area for coral to capitalize on and use as recruitment area."

Coral reefs are particularly vulnerable to climate change, because high ocean temperatures can cause corals to bleach, or expel the algae the corals depend on.

But the main threat to the corals in the Solomon Islands is not global warming, MacPherson said.

"It's actually from coral mining for coral calcium in the form of lime, which is used in the betel nut chewing practice … ," he said, referring to the regional habit of chewing the seeds of the betel palm for their stimulant effects.

"Locals will go out and harvest coral, they'll let it bleach in the sun, and then they'll burn that coral to create lime. And then the lime is used as an abrasive during betel nut chewing."

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