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Effect of carbonate ion concentration and irradiance on calcification in foraminifera
1LSCE/IPSL, laboratoire CEA/CNRS/UVSQ, LSCE-Vallée, Bât. 12, avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX, France
2Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
3INSU-CNRS, Laboratoire d'Océanographie de Villefranche-sur-mer, B.P. 28, 06234 Villefranche-sur-mer Cedex, France
4UPMC University of Paris 06, Observatoire Océanologique de Villefranche-sur-mer, 06230 Villefranche-sur-mer, France
*currently at: DTU Aqua, Technical University of Denmark, Kavalergården 6, 2920 Charlottenlund, Denmark
Abstract. The effect of carbonate ion concentration ([CO32−]) 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 [CO32−]. Both O. universa and G. sacculifer exhibited reduced final shell weight and calcification rate under low [CO32−]. At the [CO32−] expected for the end of the century, the calcification rates of these two species are projected to be 6 to 13% lower than at 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 calcite production by foraminifera and may decrease the calcite flux contribution from these organisms.
Discussion Paper (PDF, 1290 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (BG)
Citation: Lombard, F., da Rocha, R. E., Bijma, J., and Gattuso, J.-P.: Effect of carbonate ion concentration and irradiance on calcification in foraminifera, Biogeosciences Discuss., 6, 8589-8608, 2009. Bibtex EndNote Reference Manager
