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| Castel, J; Courties, C; Poli, J M. |
| The seasonal pattern of the abundance of the planktonic copepod Eurytemora hirundoides shows the highest numbers are associated with temperatures between 10 and 20 degree C. However, for this temperature range, the abundance is higher in spring than in autumn. The evolution of the intrinsic rate of increase (r sub(m), determined in laboratory), as a function of the evironmental temperature, predicts a peak abundance at the end of May which is consistent with observations. The decrease of r sub(m) occurring from 18 degree C cannot be the only explanation for the decline of the summer population. Other factors are involved: oxygen tension, competition. Two types of action of the temperature, direct in spring, indirect in summer, must be taken into account to... |
| Tipo: Text |
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| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/00247/35788/34301.pdf |
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| Castel, J; Lasserre, P. |
| The "fish reservoirs" of the Arcachon Basin (France) are artificial ponds created in lagoonal marshes. Opportunistic populations of microorganisms and of meiofauna increase the tendency to create dystrophic crisis. Fry stocking of soles (Solea vulgaris ) into the fish ponds have been made to estimate the influence of the predatory activity and bioturbation on the food web. For 10 soles/m super(2), the abundance of opportunistic populations of meiofauna decreases and this result indicates a modification in competitive interactions contributing to a better spatial heterogeneity in the ecosystem. These results could be used in aquaculture ponds to regulate opportunistic microorganisms and meiofauna. |
| Tipo: Text |
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| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/00246/35707/34216.pdf |
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| Relexans, Jc; Lin, Rg; Castel, J; Etcheber, H; Laborde, P. |
| Relationships between benthos and sedimentary organic matter quality were analyzed in the West Gironde Mud Patch (WGMP), on the shelf of the Bay of Biscay, off the Gironde estuary, as part of the multidisciplinary national programme Ecomarge, a JGOFS-France contribution. At three stations located on an east-west transect and at different periods from 1985 to 1988, the following parameters of the sediment were analyzed: POC (particulate organic carbon); SIGMA (sum of easily extractable macromolecules thought to be the most degradable part of particulate organic matter); pigments as indices of organic matter quality; ETS (electron-transport-system) activities and meiofauna densities as indices of benthic responses. Sediments from the WGMP have an overall low... |
| Tipo: Text |
Palavras-chave: BENTHOS; ELECTRON-TRANSPORT-SYSTEM (ETS); MEIOFAUNA; POC QUALITY; ORGANIC MATTER. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00101/21231/18848.pdf |
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| Santos, Pjp; Castel, J; Souzasantos, Lp. |
| The spatial variation of microphytobenthos was investigated with reference to both the estuarine gradient and the intertidal levels of the Gironde estuary, France. Four transects, each with three stations, were surveyed in two different seasons (April and October) during two consecutive years. In addition, the seasonality of microphytobenthic pigment concentration and its relationship to environmental factors were examined by means of weekly sampling at an intertidal mudflat located in the oligo-mesohaline area. Generally, microphytobenthic pigments increased both with increasing salinity and tidal height. Clear seasonal variations were found for microphytobenthic chlorophyll-a concentration. Multivariate analysis showed environmental factors such as... |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20414/18081.pdf |
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| Hussenot, Jerome; Castel, J; Fardeau, Jean-claude; Feuillet-girard, Michèle; Gautier, Dominique; Gouleau, Dominique; Legrand, C; Martin, Jean-louis; Pirastru, L; Ravail, Brigitte; Rince, Y; Sautour, Benoit. |
| Il a été étudié sur 9 bassins de terre expérimentaux de 200 m3, à l'état initial identique, l'influence de 2 types de stimulation sur les populations naturelles planctoniques et benthiques et sur la qualité physico-chimique de I'eau et du sédiment en comparaison avec des bassins de référence non stimulés. |
| Tipo: Text |
Palavras-chave: Marais aquacoles; Productivité naturelle; Fertilisants. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00020/13115/10124.pdf |
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| Quintin, Jean-yves; Castaing, P; Jouanneau, Jean-marie; Oggian, Georges; Poirier, Dominique; Chaurial, Bernard; Serceau, R; Castel, J; Sautour, Benoit. |
| Le schéma général des études écologiques relatives à l'implantation des centrales nucléaires en estuaire prévoit deux étapes: - le projet qui a pour but de préciser l'état écologique du milieu dans la zone qui subira l'influence de la centrale. - la surveillance qui correspond à l'étude des fluctuations naturelles du milieu (variations pluri-annuelles notamment) avant la mise en service de la centrale, et des modifications du milieu après la mise en service de la centrale. Projet et surveillance écologiques sont deux phases complémentaires d'une même étude, qui visent à mettre en évidence les règles évolutives d'un écosystème soumis aux effluents thermiques d'une centrale nucléaire. Les lois recherchées, utilisables à des fins prédictives, ne peuvent... |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00069/18065/15610.pdf |
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