Parameterization of the response of calcification to temperature and pCO(2) in the coral Acropora pulchra and the alga Lithophyllum kotschyanum

• Published in: Coral Reefs
• Main Authors: Comeau, S., Carpenter, R. C., Lantz, C. A., Edmunds, P. J.
• Other Authors: The University of Western Australia (UWA), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), California State University Northridge (CSUN)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Ocean acidification
• Online Access: https://hal.archives-ouvertes.fr/hal-03502975; https://doi.org/10.1007/s00338-016-1425-0

The response of tropical corals and calcifying algae to ocean acidification (OA) and warming has received much attention in the past decade. However, most studies have evaluated the response of organisms to two or three temperature treatments, which does not allow the functional relationship between calcification and temperature under ambient and future pCO(2) to be determined. This study tested the hypothesis that the relationship between calcification and temperature is affected by OA in the coral Acropora pulchra and the calcified alga Lithophyllum kotschyanum. Pieces of each organism were incubated under five (24-30 A degrees C) or six (24-31.5 A degrees C) temperatures crossed with two pCO(2) levels (400 and 1000 mu atm), and calcification was assessed in trials conducted in the spring and summer. The response of coral calcification to temperature was a positive asymmetric parabola with a maximum at similar to 28 A degrees C under both pCO(2) levels and in both seasons; the effects of pCO(2) on calcification were largest at similar to 28 A degrees C and lowest in both cool and warm temperatures. In contrast, calcification of the alga at both levels of pCO(2) was unaffected by temperature in spring, but declined linearly with temperature in summer. This study demonstrates that the calcification response of coral reef organisms to the crossed effect of warming and OA is complex and cannot be fully assessed without using multiple temperature treatments that are ecologically relevant.