How does rising atmospheric CO2 affect marine organisms?

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Coral Recipe for Surviving Global Warming and Ocean Acidification

Paper Reviewed
Towle, E.K., Enochs, I.C. and Langdon, C. 2015. Threatened Caribbean coral is able to mitigate the adverse effects of ocean acidification on calcification by increasing feeding rate. PLoS ONE 10: 10.1371/journal.pone.0123394.

Noting the concerns of many people that "global climate change threatens coral growth and reef ecosystem health via ocean warming and ocean acidification," Towle et al. (2015) took it upon themselves to examine "the ability of coral heterotrophy to mitigate reductions in growth due to climate change stress in the critically endangered Caribbean coral Acropora cervicornis via changes in feeding rate." This they did in a laboratory study where the corals in question "were either fed or unfed and exposed to elevated temperature (30°C), enriched pCO2 (800 ppm) or both (30°C/800 ppm) as compared to a control (26°C/390 ppm) for 8 weeks."

This experiment revealed, as the three researchers describe it, that the "fed corals were able to maintain ambient growth rates at both elevated temperature and elevated CO2, while unfed corals experienced significant decreases in growth with respect to fed conspecifics." In light of these findings, therefore, the three researchers write that their results "show for the first time that a threatened coral species can buffer ocean-acidification-reduced calcification by increasing feeding rates." And they thus conclude with the good-to-hear news that "a critically endangered species with access to food sources other than photosynthate may be able to maintain growth physiology under climate change stress."

Posted 17 August 2015