[en] A 4-year time series (2001–2004) of the partial pressure of CO2 (pCO2) and air-sea CO2 fluxes is
reported in the Scheldt estuarine plume. This system is oversaturated in CO2 with respect to the
atmosphere, except during the spring phytoplanktonic bloom, and acts as a net source of CO2 to the
atmosphere of 0.7 mol C m 2 yr 1 that represents 7 to 27% of the inner Scheldt estuary CO2 emission.
Results also highlight that a high spatial and temporal coverage of the surface pCO2 in coastal ecosystems
is crucial for reliable estimations of air-sea CO2 fluxes. The seasonal variations of pCO2 seem to be more
dominated by biological activities (photosynthesis/respiration) than by temperature change. A
stochiometrically linked C/P mass balance budget failed to provide net ecosystem production estimates
consistent with the pCO2 dynamics in this area. It is hypothesized that this discrepancy is related to
physiological characteristics of the dominant phytoplanktonic species (Phaeocystis sp.) within the studied
area. On the basis of a preliminary dissolved inorganic carbon input/output budget, the annual emission of
CO2 toward the atmosphere seems to be largely due to the outgassing of the inputs of CO2 from the inner
Scheldt estuary, rather than due to organic carbon degradation.
Disciplines :
Aquatic sciences & oceanology
Author, co-author :
Schiettecatte, Laure-Sophie; Université Libre de Bruxelles > Océanographie Chimique et Géochimie des Eaux
Gazeau, Frédéric; Vrije Universiteit Brussel > Analytische en Milieu Chemie
Van der Zee, Claar; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique
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