Effect of carbonate ion concentration and irradiance on calcification in planktonic foraminifera

• Published in: Biogeosciences
• Main Authors: Lombard, F., da Rocha, R., Bijma, J., Gattuso, J.-P.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Ocean acidification; Planktonic foraminifera
• Online Access: https://hal.archives-ouvertes.fr/hal-03200964; https://hal.archives-ouvertes.fr/hal-03200964/document; https://hal.archives-ouvertes.fr/hal-03200964/file/bg-7-247-2010.pdf; https://doi.org/10.5194/bg-7-247-2010

International audience The effect of carbonate ion concentration ([CO 2− 3 ]) on calcification rates estimated from shell size and weight was investigated in the planktonic foraminifera Orbulina universa and Globigerinoides sacculifer. Experiments on G. sacculifer were conducted under two irradiance levels (35 and 335 µmol photons m −2 s −1). Calcification was ca. 30% lower under low light than under high light, irrespective of the [CO 2− 3 ]. Both O. universa and G. sacculifer exhibited reduced final shell weight and calcification rate under low [CO 2− 3 ]. For the [CO 2− 3 ] expected at the end of the century, the calcification rates of these two species are projected to be 6 to 13% lower than the present conditions, while the final shell weights are reduced by 20 to 27% for O. universa and by 4 to 6% for G. sacculifer. These results indicate that ocean acidification would impact on calcite production by foraminifera and may decrease the calcite flux contribution from these organisms.