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Schmidt, S; Nival, P; Reyss, Jl; Baker, M; Buatmenard, P. |
Dissolved and particulate Th-234 activities were determined and phyto- and zooplankton biomass were periodically measured 8 miles off Nice (Mediterranean Sea) during spring 1987. The results show a strong variability of Th-234 distribution on short time scales in northwestern Mediterranean surface waters. The good correlation observed between the zooplankton biomass and the rate of Th-234 export to deep water in particulate form is in agreement with the assumption that the residence time of particulate Th-234 in oceanic surface waters is controlled by zooplankton grazing. Moreover, our results indicate the importance of salps in particular as efficient removers of small suspended particles in surface waters. |
Tipo: Text |
Palavras-chave: TH-234; ZOOPLANKTON; SCAVENGING; PARTICLE FLUX. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00100/21155/18774.pdf |
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Jouffre, D; Lamhoai, T; Millet, B; Amanieu, M. |
In order better to understand brackish ecosystem functioning, this study deals with zooplankton spatial organization in a North-Mediterranean lagoon (etang de Thau). A statistical treatment - spatial contiguity constrained clustering - is used to divide the lagoon into several homogeneous zones with regard to zooplankton communities. Confrontation between biological and physical patterns (hydroclimatic context data together with results of a numerical simulation of hydrodynamic circulation in the lagoon) tends to show that: 1) Zooplankton community spatial patterns have a short-term significance (few days) and do not reveal any seasonal characteristic; 2) Inversion of the water flows between the lagoon and the sea plays a major role in structuring and... |
Tipo: Text |
Palavras-chave: ZOOPLANKTON; COMMUNITIES; SPATIOTEMPORAL PATTERNS; ECOSYSTEM FUNCTIONING; PHYSICO-BIOLOGICAL RELATION. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00101/21272/18882.pdf |
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Bergeron, Jean-pierre. |
In temperate neritic areas, meteorological conditions prevailing during winter and the following spring play a major role on the main features of the spring development pattern of pelagic ecosystems. Interannual fluctuations of this environment lead to qualitative and quantitative variations of secondary production which may strongly influence processes regulating the recruitment of many species. A method for assessing pelagic secondary production is based on measurement of the activity of an enzyme, aspartate transcarbamylase, and has been carried out during spring periods for six years in succession, in the southwestern part of the English Channel. These works have permitted the establishment of a close correlation between the quantitative variations of... |
Tipo: Text |
Palavras-chave: ASPARTATE TRANSCARBAMYLASE; ENGLISH CHANNEL; RECRUITMENT; DOVER SOLE; ZOOPLANKTON. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00072/18303/15883.pdf |
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Sautour, B; Castel, Jerome. |
Zooplankton distribution in Marennes-Oleron Bay (France) varies during the year and is essentially determined by seasonal rhythms. The whole set of zooplanktonic taxa can be divided into three groups: the first bearing oceanic affinities; the second with estuarine tendencies; and the third more intermediate. Important water flows inhibit the establishment in a specific zone of an autochthonous community (this community is reduced to such species as Acartia discaudata, Acartia grani and Euterpina acutifrons). Zooplanktonic populations reach their maximum abundances at the end of spring and during summer, particularly during spring tide in the inner neritic zone. The estimation of die grazing pressure of copepods (which are the dominant taxa) is variable... |
Tipo: Text |
Palavras-chave: MARENNES-OLERON; ZOOPLANKTON; COPEPODS; BIOMASS; GRAZING. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00099/21055/18681.pdf |
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Corn, M; Belviso, S; Nival, P; Vigot, A; Buatmenard, P. |
We report results from free-drifting sediment trap deployments at 200 m depth which enable measurement of the diel variations in the downward flux of detrital particulate dimethylsulphoniopropionate (DMSPp) over periods of 24-72 hours in three contrasting trophic regimes of the tropical northeastern Atlantic Ocean off Mauritania. The source of DMSPp was the phytoplankton living in surficial water layers. The three regimes exhibited similar strong diel cycles, the nocturnal fluxes being up to 100-fold lower than the daytime fluxes. High (or low) detrital DMSPp, fluxes were associated with high (or low) numbers of pteropods trapped inside the sampling cups. Thus, contamination of sinking material is likely to have occurred, promoting an overestimate of the... |
Tipo: Text |
Palavras-chave: SULFUR; DMS; DMSP; ZOOPLANKTON; SEDIMENTATION. |
Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00098/20886/18500.pdf |
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Brylinski, Jm; Aelbrecht, D. |
Zooplankton and current studies were carried out in the coastal front of the Dover Strait. We show that the maintenance of both offshore and inshore planktonic communities is due to two coupled phenomena: 1) the residual drift of water differs in the upper and in the deeper waters; and 2) the vertical distribution of plankton differs for inshore and offshore species. In the frontal area, the coastal species remain in the lower water layer where the residual drift is landward. Conversely, the offshore species remain in the upper water layer where the residual drift is seaward. |
Tipo: Text |
Palavras-chave: ZOOPLANKTON; FRONT; VERTICAL MIGRATION; RECRUITMENT; ENGLISH CHANNEL. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21144/18763.pdf |
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