Seawater carbonate chemistry and calcification rates of Porites rus and Hydrolithon onkodes in experiments of Moorea

• Main Authors: Comeau, Steeve, Carpenter, Robert C, Edmunds, Peter J
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcification rate of calcium carbonate; Calcite saturation state; Calculated using seacarb; 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); DATE/TIME; Date/time end; EXP; Experiment; French Polynesia; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Hydrolithon onkodes; Irradiance; Laboratory experiment; Macroalgae; Moorea; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Rus’; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.821467; https://doi.org/10.1594/PANGAEA.821467

Central to evaluating the effects of ocean acidification (OA) on coral reefs is understanding how calcification is affected by the dissolution of CO2 in sea water, which causes declines in carbonate ion concentration [CO3]2- and increases in bicarbonate ion concentration [HCO3]-. To address this topic, we manipulated [CO3]2- and [HCO3]- to test the effects on calcification of the coral Porites rus and the alga Hydrolithon onkodes, measured from the start to the end of a 15-day incubation, as well as in the day and night. [CO3]2- played a significant role in light and dark calcification of P. rus, whereas [HCO3]- mainly affected calcification in the light. Both [CO3]2- and [HCO3]- had a significant effect on the calcification of H. onkodes, but the strongest relationship was found with [CO3]2-. Our results show that the negative effect of declining [CO3]2- on the calcification of corals and algae can be partly mitigated by the use of [HCO3]- for calcification and perhaps photosynthesis. These results add empirical support to two conceptual models that can form a template for further research to account for the calcification response of corals and crustose coralline algae to OA.