Seawater carbonate chemistry and pH at the site of calcification within the calcifying fluid/medium of coralline algae in laboratory experiment, supplement to: Cornwall, Christopher Edward; Comeau, Steeve; McCulloch, Malcolm T (2017): Coralline algae elevate pH at the site of calcification under ocean acidification. Global Change Biology

• Main Authors: Cornwall, Christopher Edward, Comeau, Steeve, McCulloch, Malcolm T
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2017
• Subjects: Acid-base regulation; Amphiroa anceps; Benthos; Calcification/Dissolution; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Indian Ocean; Laboratory experiment; Macroalgae; Neogoniolithon sp.; Plantae; Rhodophyta; Single species; Sporolithon durum; Temperate; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment duration; Identification; δ11B; Treatment; Calcifying fluid, pH; Difference; Calcification rate of calcium carbonate; 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; Temperature, water; Salinity; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Experiment; 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.875262; https://doi.pangaea.de/10.1594/PANGAEA.875262

Coralline algae provide important ecosystem services but are susceptible to the impacts of ocean acidification. However, the mechanisms are uncertain, and the magnitude is species specific. Here, we assess whether species-specific responses to ocean acidification of coralline algae are related to differences in pH at the site of calcification within the calcifying fluid/medium (pHcf) using delta 11B as a proxy. Declines in delta 11B for all three species are consistent with shifts in delta 11B expected if B(OH)4- was incorporated during precipitation. In particular, the delta11B ratio in Amphiroa anceps was too low to allow for reasonable pHcf values if B(OH)3 rather than B(OH)4- was directly incorporated from the calcifying fluid. This points towards delta 11B being a reliable proxy for pHcf for coralline algal calcite and that if B(OH)3 is present in detectable proportions, it can be attributed to secondary postincorporation transformation of B(OH)4-. We thus show that pHcf is elevated during calcification and that the extent is species specific. The net calcification of two species of coralline algae (Sporolithon durum, and Amphiroa anceps) declined under elevated CO2, as did their pHcf. Neogoniolithon sp. had the highest pHcf, and most constant calcification rates, with the decrease in pHcf being 1/4 that of seawater pH in the treatments, demonstrating a control of coralline algae on carbonate chemistry at their site of calcification. The discovery that coralline algae upregulate pHcf under ocean acidification is physiologically important and should be included in future models involving calcification. : 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 2017-05-17.