Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment

• Main Authors: Bellerby, R. G. J., Schulz, K. G., Riebesell, U., Neill, C., Nondal, G., Johannessen, T., Brown, K. R.
• Other Authors: Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences Bergen (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Geophysical Institute Bergen (GFI / BiU), University of Bergen (UiB), Leibniz Institute of Marine Science at the University of Kiel (IFM-GEOMAR), Kiel University, Mohn-Sverdrup Center and Nansen Environmental and Remote Sensing Center
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Ocean acidification
• Online Access: https://hal.science/hal-00297952; https://hal.science/hal-00297952/document; https://hal.science/hal-00297952/file/bgd-4-4631-2007.pdf

International audience Inorganic carbon and nutrient biogeochemical responses were studied during the 2005 Pelagic Ecosystem CO 2 Enrichment (PeECE III) study. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem production perturbed over a range of pCO 2 scenarios (350, 700 and 1050 ?atm). Nutrient uptake showed no sensitivity to CO 2 treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO 2 treatments which was positively correlated with the initial CO 2 concentration. There was no significant calcification response to changing CO 2 in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (~15 ?mol kg ?1 ). With insignificant air-sea CO 2 exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C:N:P stoichiometry of organic production increased with CO 2 treatment from 1:6.3:121 to 1:7.1:144 to 1:8.25:168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.