Seawater carbonate chemistry and coral calcification

• Main Authors: Edmunds, Peter J, Burgess, Scott C
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2020
• Subjects: Acropora hyacinthus; Animalia; Benthic animals; Benthos; Calcification/Dissolution; Cnidaria; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Single species; South Pacific; Temperature; Tropical; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment duration; Experiment; Size; Identification; Treatment; Diameter; Area; Calcification rate; pH; pH, standard error; Replicates; 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; Temperature, water, standard error; Salinity; Salinity, standard error; Irradiance; Irradiance, standard error; 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; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.926042; https://doi.pangaea.de/10.1594/PANGAEA.926042

Experiments with coral fragments (i.e. nubbins) have shown that net calcification is depressed by elevated PCO2. Evaluating the implications of this finding requires scaling of results from nubbins to colonies, yet the experiments to codify this process have not been carried out. Building from our previous research demonstrating that net calcification of Pocillopora verrucosa (2–13 cm diameter) was unaffected by PCO2 (400 and 1000 µatm) and temperature (26.5 and 29.7°C), we sought generality to this outcome by testing how colony size modulates PCO2 and temperature sensitivity in a branching acroporid. Together, these taxa represent two of the dominant lineages of branching corals on Indo-Pacific coral reefs. Two trials conducted over 2 years tested the hypothesis that the seasonal range in seawater temperature (26.5 and 29.2°C) and a future PCO2 (1062 µatm versus an ambient level of 461 µatm) affect net calcification of an ecologically relevant size range (5–20 cm diameter) of colonies of Acropora hyacinthus. As for P. verrucosa, the effects of temperature and PCO2 on net calcification (mg day−1) of A. verrucosa were not statistically detectable. These results support the generality of a null outcome on net calcification of exposing intact colonies of branching corals to environmental conditions contrasting seasonal variation in temperature and predicted future variation in PCO2. While there is a need to expand beyond an experimental culture relying on coral nubbins as tractable replicates, rigorously responding to this need poses substantial ethical and logistical challenges. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2020) 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 2020-12-11.