A propos du rôle des bactéries planctoniques dans les ecosystèmes marins: communication présentée à l'Ecole Européenne d'Eté d'Environnement, Louvain-la-Neuve, juillet 1977
Joiris, C. (1977). A propos du rôle des bactéries planctoniques dans les ecosystèmes marins: communication présentée à l'Ecole Européenne d'Eté d'Environnement, Louvain-la-Neuve, juillet 1977. Vrije Universiteit Brussel: Louvain-la-Neuve. 21 pp. |  |
| Abstract | Resulting from synecological studies in some areas of the southern North Sea, a contradiction became evident between measurements of primary production and determinations of the activities consuming organic matter. In the Southern Bight, the consumption is 10 to 20 times higher than the production. This means that the primary production has been underestimated, and/or the consumption over-estimated. In order to discuss the validity of the methods used for determining the respiration activities, some results are presented: a. during a 24 h. cycle at the Sluice-Dock of Ostend, the variations of the oxygen concentration in the water are explained by the measured activities and diffusion fluxes; b. two different methods are shown to give comparable results : the initial rate of oxygen consumption and the anapheratic fixation of CO2.The extrapolation of measured respiration rates in function of time and depth is discussed. The obtained results for organic matter, respiration activities and their ratio: the turnover rate, are compared with other ones from the literature. No argument was found against the validity of the methods used for the determination of respiration activities. There- fore, it is suggested to look also for possible errors in the evaluation of primary production, and more particularly to the respiration and excretion activities of phytoplancton in the dark: at night and under the euphatic zone. |
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