"Calcification and respiration are continually happening at these sites while the water sits there, allowing the water to become more and more acidic. It's a little bit like being stuck in a room with a limited amount of oxygen--the longer you're in there without opening a window, you're using up oxygen and increasing carbon dioxide."
Ordinarily, she added, without fresh air coming in, it would become harder and harder for living things to thrive, "yet in the case of the corals in Palau, we're finding the opposite. Coral cover and diversity actually increase from the outer reefs into the Rock Islands."
The next steps are to determine whether the corals are genetically adapted to low pH, or whether Palau provides a "perfect storm" of environmental conditions.
"If it's the latter, it means that if you took those corals out of that specific environment and put them in another low pH environment that doesn't have the same combination of conditions, they wouldn't be able to survive," said Cohen. "But if they're genetically adapted to low pH, you could put them anywhere."
"These reef communities have developed under these conditions for thousands of years," said Shamberger. "These are conditions that are going to be occurring in a lot of the ocean by the end of the century.
"We don't know if other coral reefs will be able to adapt to ocean acidification--the time scale might be too short."
The scientists are careful to stress that their findings in Palau are different from every other low pH environment that has been studied.
"When we discover a reef like Palau where the coral communities are thriving under low pH, that's an exception," said Cohen.
"It doesn't mean that coral reefs
|Contact: Cheryl Dybas|
National Science Foundation