How does rising atmospheric CO2 affect marine organisms?

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The Response of a Coral Reef Sea Urchin to Ocean Acidification

Paper Reviewed
Moulin, L., Grosjean, P., Leblud, J., Batigny, A. and Dubois, P. 2014. Impact of elevated pCO2 on acid-base regulation of the sea urchin Echinometra mathaei and its relation to resistance to ocean acidification: A study in Mesocosms. Journal of Experimental Marine Biology and Ecology 457: 97-104.

Moulin et al. (2014) say it has been suggested that in numerous marine organisms several physiological processes may be directly or indirectly impacted by the induced acidosis and hypercapnia produced by continued atmospheric CO2 enrichment; and they indicate that species with low metabolism and inefficient ion regulatory abilities have been suggested to be "more sensitive to a high seawater pCO2," citing Melzner et al. (2009).

In light of these facts, Moulin et al. set forth to evaluate "the acid-base regulation of the coral reef sea urchin Echinometra mathaei and the impact of decreased pH on its growth and respiration activity," which they did "in two identical artificial reef mesocosms during seven weeks," when the experimental tanks were maintained at mean pH values of 8.05 (standard) and 7.7 ("acidified"), together with "field-like night and day variations."

In describing their findings, the five Belgian researchers report that "E. mathaei can regulate the pH of its coelomic fluid in the considered range of pH." As a result, Moulin et al. conclude that this ability allows "a sustainable growth" and ensures "an unaffected respiratory metabolism, at least at short term." And that effectively diminishes metabolism-based concerns for this marine species under elevated CO2 conditions.

Melzner, F., Gutowska, M.A., Langenbuch, M., Dupont, S., Lucassen, M., Thorndyke, M.C., Bleich, M. and Portner, H.-O. 2009. Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny? Biogeosciences 6: 2313-2331.

Posted 24 October 2014