|The pigment labelling method to estimate "new production" in the sea|
Cailliau, C.; Claustre, H.; Quéguiner, B.; Tréguer, P. (1998). The pigment labelling method to estimate "new production" in the sea, in: Dehairs, F.A. et al. (Ed.) Integrated Marine System Analysis. European Network for Integrated Marine System Analysis FWO Vlaanderen: Proceedings of the second network meeting (Brussels, May 29-31, 1997). pp. 165-171
In: Dehairs, F.A.; Elskens, M.; Goeyens, L. (Ed.) (1998). Integrated Marine System Analysis. European Network for Integrated Marine System Analysis FWO Vlaanderen: Proceedings of the second network meeting (Brussels, May 29-31, 1997). VUB. Laboratorium voor Analytische Chemie: Brussel. 376 pp., more
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VLIZ: Proceedings D 
|Document type: Conference paper|
Biological production; Marine
|Authors|| || Top |
- Cailliau, C.
- Claustre, H.
- Quéguiner, B.
- Tréguer, P., more
In our attempt to estimate, both spatially and temporally, the magnitude and variability of new production in the ocean, the pigment labeling method is an adequate tool. This method is essentially an extension of the basic 14C technique for measuring primary production in the sea. When phytoplankton is incubated in the presence of H14CO-3, the labeled C is incorporated into organic substrates including the different pigments. The modelisation of the incorporation rate of labeled carbon into the different pigments, some of them being very specific, allows the estimate of phytoplankton specific growth rates, free from artefacts due to zooplankton grazing in the incubation bottle. Indeed, determination of the growth rate is based on determination of the pigment specific activity (dpm/µgC), which is a ratio, and thus does not depend on the absolute pigment concentration within the experiment bottle. "New production" is generally attributed to diatoms (and dinoflagellates). A factor, *f-ratio, is here defined as the sum of fucoxanthin (diatoms) and peridinin (dinoflagellates) specific activities, divided by the sum of specific activities of all pigments. This ratiorepresents the part of the labeled carbon incorporation rate by diatoms (and dinoflagellates) to the total incorporation rate of labeled carbon by the total phytoplankton community .In other terms, this ratio characterizes the proportion of "new production" (more precisely the "exportable" production) to total primary production. "New production" is thus estimated, on a short time scale, from the evaluation of the *Fp-ratio and that of primary production, both measured and calculated independently.Additionally, another ratio, the Tp-ratio, is defined as the sum of fucoxanthin (and peridinin) fluxes (µg m-2j-1) measured above the euphotic zone, divided by the sum of fluxes of all pigments. This ratio represents the contribution of diatoms (and dinoflagellates) to the total exported production.The comparison of these two ratios, both estimated from the same pigment signatures, allows a more realistic description of the phytoplankton dynamic on short time scales.