Thursday, September 10, 2009

Ocean acidification update, part whatever..

Some recent studies report:

* subtropical corals showing a net loss of calcium carbonate under decreased ocean pH:
These experimental results provide support for the conclusion that some net calcifying communities could become subject to net dissolution in response to anthropogenic ocean acidification within this century.
* the results of experiments on a couple of planktonic foraminifera (which are a small critter that produces calcium carbonate shells) do not like more CO2:
At the [CO32−] expected for the end of the century, the calcification rates of these two species are projected to be 6 to 13% lower than at present conditions, while the final shell weights are reduced by 20 to 27% for O. universa and by 4 to 6% for G. sacculifer. These results indicate that ocean acidification would impact calcite production by foraminifera and may decrease the calcite flux contribution from these organisms.
* bivalves in Antarctic waters (the first predicted to suffer increased ocean acidification) don't take it well either:
After 5 weeks the shells and thallus of the coralline alga had suffered significant dissolution when compared to controls. Moroever, one of the shells of the bivalve L. elliptica in acidified seawater became so fragile it fragmented into multiple pieces. Our findings indicate that antarctic calcified seafloor macroorganisms, and the communities they comprise, are likely to be the first to experience the cascading impacts of ocean acidification.
* Pteropods, and important fish food, show significantly reduced calcification at pH levels predicted for 2100:
This result supports the concern for the future of pteropods in a high-CO2 world, as well as of those species dependent upon them as a food resource. A decline of their populations would likely cause dramatic changes to the structure, function and services of polar ecosystems.
Remember, boys and girls, reducing CO2 is not just about warming.

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