Impacts of Ocean Acidification on Shelled Pteropods in the
Roughly a third of the anthropogenic carbon dioxide emitted into the atmosphere has been taken up by the ocean (Sabine et al., 2004), where it changes both the biological and geochemical processes. The carbon dioxide makes the sea water more acidic and shifts the chemical equilibrium towards smaller...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.503.2799 http://www.up.ethz.ch/education/term_paper/blank_termpaper_fs07_final.pdf |
| Summary: | Roughly a third of the anthropogenic carbon dioxide emitted into the atmosphere has been taken up by the ocean (Sabine et al., 2004), where it changes both the biological and geochemical processes. The carbon dioxide makes the sea water more acidic and shifts the chemical equilibrium towards smaller carbonate ion concentrations. The Southern Ocean is naturally poor in carbonate ions due to its position in the global ocean circulation system and is thus especially vulnerable to changes induced through carbon dioxide uptake (Sarmiento and Gruber, 2006). In this ecosystem planktonic shelled mollusc, such as pteropods, are abundant. They use carbonate ions and dissolved calcium to form aragonite for their shells. For them to be able to make those shells the water has to be supersaturated with respect to carbonate. In general, surface waters have higher carbonate ion concentrations and are thus supersaturated with respect to aragonite, while the deep sea has lower carbonate ion concentrations and is thus undersaturated. As the ocean takes up anthropogenic carbon dioxide, the saturated part of the water column shrinks. According to simulations of the IS92a scenario (IPCC, 2000) the whole water column of the Southern Ocean will become undersaturated with regard to aragonite by the end of this century (Orr et al., 2005). That poses a |
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