Abstract
The fixation of dissolved inorganic carbon (DIC) by marine phytoplankton provides an important feedback mechanism on concentrations of CO2 in the atmosphere. As a consequence it is important to determine whether oceanic primary productivity is susceptible to changing atmospheric CO2 levels. Among numerous other factors, the acquisition of DIC by microalgae particularly in the polar seas is projected to have a significant effect on future phytoplanktonic production and hence atmospheric CO2 concentrations. Using the isotopic disequilibrium technique the contribution of different carbon species (CO2 and bicarbonate) to the overall DIC uptake and the extent to which external Carbonic Anhydrase (eCA) plays a role in facilitating DIC uptake was estimated. Simultaneous uptake of CO2 and HCO3- was observed in all cases, but the proportions in which different DIC species contributed to carbon assimilation varied considerably between stations. Bicarbonate as well as CO2 could be the major DIC source for local phytoplankton assemblages. There was a positive correlation between the contribution of CO2 to total DIC uptake and ambient concentration of CO2 in seawater suggesting that Southern Ocean microalgae could increase the proportion of CO2 uptake under future high atmospheric CO2 levels. Results will be discussed in view of metabolic costs related to DIC acquisition of Southern Ocean phytoplankton. (C) 2011 Elsevier Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 2636-2646 |
Number of pages | 11 |
Journal | Deep-Sea research part ii-Topical studies in oceanography |
Volume | 58 |
Issue number | 25-26 |
DOIs | |
Publication status | Published - 15-Dec-2011 |
Keywords
- Carbon sink
- CO2 concentrating mechanism
- HCO3-
- Carbonic anhydrase
- Isotope disequilibrium technique
- Weddell Sea
- ISOTOPIC DISEQUILIBRIUM TECHNIQUE
- MARINE-PHYTOPLANKTON
- IRON LIMITATION
- CO2-CONCENTRATING MECHANISMS
- CONCENTRATING MECHANISMS
- ENRICHMENT EXPERIMENTS
- BICARBONATE TRANSPORT
- LIGHT AVAILABILITY
- ANHYDRASE ACTIVITY
- GROWTH-RATES
Datasets
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(Table 1) Nitrate, phosphate, silicate and CO2 concentrations in water samples obtained during POLARSTERN cruise ANT-XXIV/3
Neven, I. (Contributor), Stefels, J. (Contributor), van Heuven, S. (Contributor), Baar ,de, H. (Contributor) & Elzenga, T. (Contributor), University of Groningen, 8-Aug-2011
DOI: 10.1594/PANGAEA.817740, https://doi.pangaea.de/10.1594/PANGAEA.817740
Dataset
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(Table 3) Contribution of different C species and eCA to phytoplanktonic DIC uptake in water samples obtained during POLARSTERN cruise ANT-XXIV/3
Neven, I. (Contributor), Stefels, J. (Contributor), van Heuven, S. (Contributor), Baar ,de, H. (Contributor) & Elzenga, T. (Contributor), University of Groningen, 8-Aug-2011
DOI: 10.1594/PANGAEA.817742, https://doi.pangaea.de/10.1594/PANGAEA.817742
Dataset
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(Table 2) Chorophyll a concentration and phytoplankton classes in water samples obtained during POLARSTERN cruise ANT-XXIV/3
Neven, I. (Contributor), Stefels, J. (Contributor), van Heuven, S. (Contributor), Baar ,de, H. (Contributor) & Elzenga, T. (Contributor), University of Groningen, 8-Aug-2011
DOI: 10.1594/PANGAEA.817741, https://doi.pangaea.de/10.1594/PANGAEA.817741
Dataset