caa a22 4500 445820330 CHVBK 20180317145242.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s00338-010-0697-z doi (NATIONALLICENCE)springer-10.1007/s00338-010-0697-z The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals [Elektronische Daten] [S. de Putron, D. McCorkle, A. Cohen, A. Dillon] 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 2weeks 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 nonlinear. 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 variable responses is needed to support informed predictions about future OA impacts on corals and coral reefs. Springer-Verlag, 2010 Coral nationallicence Calcification nationallicence Ocean acidification nationallicence Recruitment nationallicence Carbonate ion nationallicence de Putron S. Bermuda Institute of Ocean Sciences, 17 Biological Lane, Ferry Reach, GE 01, St. Georges, Bermuda aut McCorkle D. Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA aut Cohen A. Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA aut Dillon A. Department of Ecology and Evolutionary Biology, Princeton University, 08544, Princeton, NJ, USA aut Coral Reefs Springer-Verlag 30/2(2011-06-01), 321-328 0722-4028 30:2<321 2011 30 338 https://doi.org/10.1007/s00338-010-0697-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00338-010-0697-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- de Putron S. Bermuda Institute of Ocean Sciences, 17 Biological Lane, Ferry Reach, GE 01, St. Georges, Bermuda aut NATIONALLICENCE 700 1- McCorkle D. Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA aut NATIONALLICENCE 700 1- Cohen A. Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA aut NATIONALLICENCE 700 1- Dillon A. Department of Ecology and Evolutionary Biology, Princeton University, 08544, Princeton, NJ, USA aut NATIONALLICENCE 773 0- Coral Reefs Springer-Verlag 30/2(2011-06-01), 321-328 0722-4028 30:2<321 2011 30 338 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer