How does rising atmospheric CO2 affect marine organisms?

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Effects of Atmospheric CO2 Enrichment on a Symbiotic Anemone

Paper Reviewed
Hoadley, K.D., Rollison, D., Pettay, D.T. and Warner, M.E. 2015. Differential carbon utilization and asexual reproduction under elevated pCO2 conditions in the model anemone, Exaiptasia pallida, hosting different symbionts. Limnology and Oceanography 60: 2108-2120.

In an intriguing study published in Limnology and Oceanography, Hoadley et al. (2015) exposed several Exaiptasia pallida anemones -- hosting specimens of three different strains of the endosymbiotic dinoflagellate Symbiodinium minutum -- to either ambient or elevated pCO2 concentrations (35 or 70.9 Pa) for a period of 28 days, while concomitantly measuring a number of different anemone responses to these two pCO2 concentrations. And what did they thereby learn?

The four U.S. researchers report that (1,2) "autotrophic carbon fixation, along with the rate of carbon translocated to the animal, were significantly elevated with high pCO2," that (3) "elevated pCO2 exposure also coincided with significantly greater asexual budding rates in all tested anemones," that (4,5) "differences in photochemistry and carbon translocation rates suggest subtle differences in the response to pCO2 exposure also coincided with significantly greater asexual budding rates in all tested anemones."

In further discussing their findings, Hoadley et al. go on to state that they illustrate (6) "the potential for physiological diversity at the subspecies level for this ecologically important dinoflagellate," which further portends (7) "a potential benefit from ocean acidification (OA) not yet observed within corals," which ultimately (8) "may enable these anthozoans to gain a greater ecological presence under future OA conditions."

Posted 22 March 2016