Here's some bad ocean acidification news for us all, about coccoliths (the calcium carbonate shells of some algae.)
"We know that the world's oceans are acidifying due to our emissions of CO2 and that is why it is interesting for us to find out how the coccoliths are reacting to it. We have studied algae from both fossils and living coccoliths, and it appears that both are protected from dissolution by a very thin layer of organic material that the algae formed, even though the seawater is extremely unsaturated relative to calcite. The protection of the organic material is lost when the pH is lowered slightly. In fact, it turns out that the shell falls completely apart when we do experiments in water with a pH value that many researchers believe will be the found in the world oceans in the year 2100 due to the CO2 levels," explains Tue Hassenkam, who is part of the NanoGeoScience research group at the Department of Chemistry, University of Copenhagen.
Professor of Biological Oceanography Katherine Richardson has followed research in the acidification of the oceans and climate change in general and she hopes that the results can help to bring the issue into public focus.
"These findings underscore that the acidification of the oceans is a serious problem. The acidification has enormous consequences not only for coccoliths, but also for many other marine organisms as well as the global carbon cycle.".....
And from the abstract of the PNAS paper itself:
However, ancient and modern coccoliths, that resist dissolution in Ca-free artificial seawater at pH > 8, all dissolve when pH is 7.8 or lower. Ocean pH is predicted to fall below 7.8 by the year 2100, in response to rising CO2 levels. Our results imply that at these conditions the advantages offered by the biogenic nature of calcite will disappear putting coccoliths on algae and in the calcareous bottom sediments at risk.This is the worst sounding bit of ocean acidification research that has come out for quite some time.
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