UK, May 29, 2011 (BBC): The sea off Papua New Guinea is bubbling. Carbon dioxide seeps into the water from the slopes of a dormant volcano here, making it slightly more acidic. The resulting waters are a natural laboratory for what marine life would be like soon, in an ocean like that predicted by most models of global warming to be only decades away.
“This is the most realistic experiment done to date on this issue,” said Chris Langdon, a coral specialist from the Rosenstiel School of Marine and Atmospheric Science in Miami, US.
Coral cannot form its shell in such conditions, and it either stops growing or dies.
Seawater has an average pH of about 8.1 today, already lower than before the industrial age. The Intergovernmental Panel on Climate Change (IPCC) projects that by the end of the century, emissions may have risen so much that pH may fall to 7.8 — which happens to be precisely the general pH at the Papua New Guinea site.
In an even more acid part of the study site, with a pH of 7.7, the scientists report that coral is gone and seagrasses came to dominate the floor – though they lack the hard-shelled snails that normally live on their fronds.
“The results are complex, but their implications chilling,” commented Alex Rogers from the University of Oxford, who was not part of the study team.