Seawater carbonate chemistry and coral calcifying fluid pH and calcification, supplement to: Comeau, Steeve; Cornwall, Christopher Edward; McCulloch, Malcolm T (2017): Decoupling between the response of coral calcifying fluid pH and calcification to ocean acidification. Scientific Reports, 7(1)

• Main Authors: Comeau, Steeve, Cornwall, Christopher Edward, McCulloch, Malcolm T
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2017
• Subjects: Acid-base regulation; Acropora yongei; Animalia; Benthic animals; Benthos; Biomass/Abundance/Elemental composition; Calcification/Dissolution; Cnidaria; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Indian Ocean; Laboratory experiment; Pocillopora damicornis; Single species; Temperate; Type; Species; Registration number of species; Uniform resource locator/link to reference; Treatment; δ11B; Calcifying fluid, pH; Boron/Calcium ratio; Calcifying fluid, dissolved inorganic carbon; Calcification rate of calcium carbonate; Salinity; pH; pH, standard error; Alkalinity, total; Alkalinity, total, standard error; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air, standard error; Aragonite saturation state; Aragonite saturation state, standard error; Temperature, water; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Calcite saturation state; Potentiometric; Potentiometric titration; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Cornwall; Indian; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.892497; https://doi.pangaea.de/10.1594/PANGAEA.892497

Evaluating the factors responsible for differing species-specific sensitivities to declining seawater pH is central to understanding the mechanisms via which ocean acidification (OA) affects coral calcification. We report here the results of an experiment comparing the responses of the coral Acropora yongei and Pocillopora damicornis to differing pH levels (8.09, 7.81, and 7.63) over an 8-week period. Calcification of A. youngei was reduced by 35% at pH 7.63, while calcification of P. damicornis was unaffected. The pH in the calcifying fluid (pHcf) was determined using delta 11B systematics, and for both species pHcf declined slightly with seawater pH, with the decrease being more pronounced in P. damicornis. The dissolved inorganic carbon concentration at the site of calcification (DICcf) was estimated using geochemical proxies (B/Ca and delta 11B) and found to be double that of seawater DIC, and increased in both species as seawater pH decreased. As a consequence, the decline of the saturation state at the site of calcification (Ωcf) with OA was partially moderated by the DICcf increase. These results highlight that while pHcf, DICcf and Ωcf are important in the mineralization process, some corals are able to maintain their calcification rates despite shifts in their calcifying fluid carbonate chemistry. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2018-07-12.