Marine scientists working on the coral reefs of Palau have made two unexpected discoveries that could provide insight into corals' resistance and resilience to ocean acidification.
The team collected water samples at nine points along a transect that stretched from the open ocean, across a barrier reef, into a lagoon, and into the bays and inlets around the Rock Islands of Palau in the western Pacific Ocean.
With each location they found that the seawater became increasingly more acidic as they moved toward land.
"When we first plotted those data, we were shocked," said chemical oceanographer Kathryn Shamberger of the Woods Hole Oceanographic Institution (WHOI). "We had no idea the level of acidification we would find. We're looking at reefs today that have levels that we expect for the open ocean in that region by the end of the century."
Shamberger conducted the fieldwork with other WHOI researchers, including biogeochemist Anne Cohen, as well as with scientists from the Palau International Coral Reef Center.
The National Science Foundation (NSF) funded the research through its Ocean Acidification Program, part of the agency's Science, Engineering and Education for Sustainability Investment.
"This important study documents a coral reef system that's apparently resistant to the effects of ocean acidification," said David Garrison, program director in NSF's Division of Ocean Sciences. "Understanding what factors account for this will be critical follow-on research."
While ocean chemistry varies naturally at different locations, it is changing around the world due to increased levels of carbon dioxide in the atmosphere.
The ocean absorbs atmospheric carbon dioxide, which reacts with seawater, lowering the water's overall pH and making it more acidic.
This process also removes carbonate ions needed by corals and other organisms to build their skeletons and shells.
|Contact: Cheryl Dybas|
National Science Foundation