Coral calcifying fluid pH dictates response to ocean acidification

• Main Authors: Holcomb, Michael, Venn, Alexander A, Tambutté, Eric, Tambutté, Sylvie, Allemand, Denis, Trotter, Julie, McCulloch, Malcolm T
• Format: Dataset
• Language: English
• Published: PANGAEA 2014
• Subjects: Acid-base regulation; Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcifying fluid; pH; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); Difference; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Group; Growth; relative; Growth/Morphology; Identification; Incubation duration; Laboratory experiment; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Potentiometric; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.843920; https://doi.org/10.1594/PANGAEA.843920

Ocean acidification driven by rising levels of CO2 impairs calcification, threatening coral reef growth. Predicting how corals respond to CO2 requires a better understanding of how calcification is controlled. Here we show how spatial variations in the pH of the internal calcifying fluid (pHcf) in coral (Stylophora pistillata) colonies correlates with differential sensitivity of calcification to acidification. Coral apexes had the highest pHcf and experienced the smallest changes in pHcf in response to acidification. Lateral growth was associated with lower pHcf and greater changes with acidification. Calcification showed a pattern similar to pHcf, with lateral growth being more strongly affected by acidification than apical. Regulation of pHcf is therefore spatially variable within a coral and critical to determining the sensitivity of calcification to ocean acidification.