Determination of particulate and dissolved primary production using kinetic experiments of 14C incorporation
Morán, J.A.G.; Estrada, M. (1998). Determination of particulate and dissolved primary production using kinetic experiments of 14C incorporation, 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. 97-110 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 |
| Keywords | Biological production > Primary production
Isotopes > Radioisotopes > Carbon isotopes > Carbon 14
Organic matter > Carbon > Organic carbon > Dissolved organic matter > Dissolved organic carbon
Organic matter > Particulates > Particulate organic matter > Organic carbon > Particulate organic carbon
Marine/Coastal |
| Abstract | The production rates of POG and DOG in Gerlache and Bransfield Straits during December 1995-january 1996 (FRUELA 95 cruise) were estimated by means of time-course experiments of 14G-bicarbonate incorporation. A three-compartment carbon exchange model was used. This method was adopted to avoid the artifacts that may appear in end-point experiments due to heterotrophic removal of recently released DOG. A good agreement was found between total organic carbon production rate and the sum of DOG and POG production rates estimated separately (r2=0.94) Overall, the assumption of linearity in end-point experiments appeared to be warranted to POG production rate, but not for DOG production Two types of kinetic curves for DO14G production were found: linear and asymptotic. This difference can be explained in terms of the simultaneous heterotrophic removal of released DOG during the experiment. On average, percentage extracellular release (PER) derived from kinetic experiments was 5% higher than in end-point experiments, although the difference in single cases could be as high as 4-fold. PER for all stations ranged from 3% to 47%, with an average of 24%. In surface waters, POG and DOG production rates were higher in Gerlache Strait than in Bransfield Strait and the Gerlache-Bransfield Confluence. PER values followed an opposite trend. With pooled data from all incubations, there was a positive relationship between log (DOG) and log (POG), but with a slope significant I y smaller than 1. A positive relationship between heterotrophic bacterial production rate (BP), as measured from 3H- Leucine uptake, and DOG production rate was found in the experiments made in Bransfield Strait, but no relationship was found in Gerlache Strait. This difference is discussed in terms of the ecological characteristics of both regions. |
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