The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals
de Putron, Samantha J.
McCorkle, Daniel C.
Cohen, Anne L.
Dillon, A. B.
MetadataShow full item record
Rising concentrations of atmospheric CO2 are changing the carbonate chemistry of the oceans, a process known as ocean acidification (OA). Absorption of this CO2 by the surface oceans is increasing the amount of total dissolved inorganic carbon (DIC) and bicarbonate ion (HCO3 -) available for marine calcification, yet is simultaneously lowering the seawater pH and carbonate ion concentration ([CO3 2-]), and thus the saturation state of seawater with respect to aragonite (Ωar). We investigated the relative importance of [HCO3 -] versus [CO3 2-] for early calcification by new recruits (primary polyps settled from zooxanthellate larvae) of two tropical coral species, Favia fragum and Porites astreoides. The polyps were reared over a range of Ωar values, which were manipulated by both acid-addition at constant pCO2 (decreased total [HCO3 -] and [CO3 2-]) and by pCO2 elevation at constant alkalinity (increased [HCO3 -], decreased [CO3 2-]). Calcification after two weeks was quantified by weighing the complete skeleton (corallite) accreted by each polyp over the course of the experiment. Both species exhibited the same negative response to decreasing [CO3 2-] whether Ωar was lowered by acid-addition or by pCO2 elevation - calcification did not follow total DIC or [HCO3 -]. Nevertheless, the calcification response to decreasing [CO3 2-] was non-linear. A statistically significant decrease in calcification was only detected between Ωar = < 2.5 and Ωar = 1.1 – 1.5, where calcification of new recruits was reduced by 22 – 37 % per 1.0 decrease in Ωar. Our results differ from many previous studies that report a linear coral calcification response to OA, and from those showing that calcification increases with increasing [HCO3 -]. Clearly, the coral calcification response to OA is variable and complex. A deeper understanding of the biomineralization mechanisms and environmental conditions underlying these 3 variable responses is needed to support informed predictions about future OA impacts on corals and coral reefs.
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Coral Reefs 30 (2011): 321-328, doi:10.1007/s00338-010-0697-z.
Suggested CitationPreprint: de Putron, Samantha J., McCorkle, Daniel C., Cohen, Anne L., Dillon, A. B., "The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals", 2010-11-05, https://doi.org/10.1007/s00338-010-0697-z, https://hdl.handle.net/1912/4641
Showing items related by title, author, creator and subject.
Coral calcification : insights from inorganic experiments and coral responses to environmental variables Holcomb, Michael (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-02)Coral calcification is examined using a laboratory model and living corals. In the laboratory model, abiogenic aragonite formed at high saturation state (Ω>~20) had a granular appearance and was enriched in trace elements, ...
Calcification Rates and Biomass of 4 Coral Species, 2 Temperatures and 2 pCO2 Levels from Experiments at LTER site in Moorea, French Polynesia, 2011 (OA_Corals project) Edmunds, Peter J. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2016-04-11)This dataset contains area-normalized calcification (mg cm-2 d-1) and biomass normalized calcification (mg mg-1) for Pocillopora meandrina, massive Porites spp., Acropora pulchra and Millepora platyphylla, as a function ...
Tank seawater conditions from Coral/Temperature/pCO2 Experiments at LTER site in Moorea, French Polynesia, 2011 (OA_Corals project) Edmunds, Peter J. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2016-04-11)Summary of conditions in the eight tanks assigned randomly to create four treatments of ambient or high temperature and ambient or high CO2. These tanks were used to examine the responses of four species of calcifying coral ...