Data/hora: 10/06/2024 16:21:52

Provedor de dados: | 5
País: | France
Título: | Evolution de communautés phytoplanctoniques après fertilisation modérée
Autores: | Jacques, G.; De Billy, G.
Data: | 1979
Ano: | 1979
Palavras-chave: | Phytoplancton; Fertilisation; Chémostat.; Phytoplankton; Nutrient; Enrichment; Chemostat.
Resumo: | One approach to the problem of aquaculture consists in a simple acceleration of natural processes in extended areas of salt or brackish water. From this point of view, the authors have been in­terested in the effect of moderate fertilization on natural communi­ties . A first series of experiments (8) was made in an exter­nal tank of 3000 liters. After fertilization, the development of flowering diatoms was obtained each time. The time of latency, the level of production reached, the composition of the final communities is to some extent variable, but bacterial development may be neglec­ted. In contrast to earlier results, obtained in small volumes of water, these experiments have always led to simplified communities mostly dominated by the diatom Skeletonema costatum. The biomass rea­ched, after a fertilization simulating "an upwelling" of mediterra­nean deep water, is of the same order as the highest amount observed in natural oceanic regions, from 20 to 30 mg Chl. a.m-3. A second series of experiments (4) was made by means of a chemostat whereby a continual flux of nutrients also simulated an upwelling. In the equilibrium stage, the biomass reached is close to that observed in the tank, but the remarkable fact is the great flexibility of adaption of the plurispecific communities. The equi­librium state is reached (for the same enrichment) with the range of increased flux from 30% to 150% a day. The diversity is higher than in the large tank and the role of Skeletonema costatum is negligible. The communities are dominated by Nitzschia closterium and by smaller forms of Chaetoceros : in particular, C. simplex, C. insignis, C. curvisetus. The problem of control of the specific composition still persists.
Tipo: | Text
Idioma: | Francês

Identificador:

http://archimer.ifremer.fr/doc/00306/41688/40897.pdf

http://archimer.ifremer.fr/doc/00306/41688/

Editor: | Publications du Centre National pour l'Exploitation des Océans (CNEXO). Série : Actes de colloques, n° 7, 1979, pp. 715-742
Formato: | application/pdf

Fonte:

Centre National pour l’Exploitation des Océan, 1979

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