|Experimental and theoretical approach of the production and transformation of organic matter in a semi-enclosed basin|
Dubois, D.M.; Mayzaud, P. (1976). Experimental and theoretical approach of the production and transformation of organic matter in a semi-enclosed basin, in: Persoone, G. et al. (Ed.) Proceedings of the 10th European Symposium on Marine Biology, Ostend, Belgium, Sept. 17-23, 1975: 2. Population dynamics of marine organisms in relation with nutrient cycling in shallow waters. pp. 231-245
In: Persoone, G.; Jaspers, E. (Ed.) (1976). Proceedings of the 10th European Symposium on Marine Biology, Ostend, Belgium, Sept. 17-23, 1975: 2. Population dynamics of marine organisms in relation with nutrient cycling in shallow waters. IZWO/Universa Press: Wetteren. ISBN 90-6281-002-0. 712 pp., more
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|Document type: Conference paper|
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- Dubois, D.M.
- Mayzaud, P., more
In this paper a mathematical model of the phytoplankton and the herbivorous zooplankton populations is presented, which takes into account the importance of the very large pool of non-living particulate matter and the possible capability of the herbivorous copepods to adjust their assimilation to the food concentration. From chemical analysis of deep particulate matter, the detrital carbon appears to be constituted of protein, carbohydrates and lipids and its nutritive value cannot be ignored. Herbivorous copepods graze on both living and non-living carbon as long as the size of the particles are suitable for the animal. The study of digestive enzymes of copepods also shows that the enzyme activity varies with the food concentration. This suggests that grazers are unlikely to be involved in phenomena such as superfluous feeding or even feeding at saturation level. From experimental and theoretical considerations, it appears that grazing is directly a function of the adaptation time of the grazers to their food available. For mesoscale spatio-temporal variations of populations, the Ivlev-Parsons' grazing curve must be modified to take into account the fact that, due to acclimation, the saturation level must be a function of the food available. Since most of the models of marine food chain are considering phytoplankton as the major food source and grazing as passively following the Ivlev-Parsons' equation, the characteristics described are bound to change the overall dynamics of such models.