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| Dauchez, S; Queguiner, B; Treguer, P; Zeyons, C. |
| Nitrogen (N-15) and carbon (C-14) uptake rates and hydrological, chemical and biological parameters were monitored at a single station during spring (March-April 1989) in a coastal eutrophic ecosystem of western Europe : the Bay of Brest. Before the spring growth of phytoplankton populations, total nitrogen and carbon uptake rates were low (almost-equal-to 0.3-mu-mol C.1(-1).h-1 and almost-equal-to 0.025-mu-mol N.l(-1).h-1). During the spring bloom, these uptake rates reached high values (0.5-mu-mol C.1(-1).h-1 and 0.28-mu-mol N.1(-1).h-1); at this time, nitrate was the main source of nitrogen production, although relative preference index (RPI) values showed that ammonium was the preferred nitrogen form for phytoplankton (RPI (NO3) < 1 ; RPI (NH4) >... |
| Tipo: Text |
Palavras-chave: CARBON UPTAKE; EUTROPHIC ECOSYSTEM; NITROGEN UPTAKE; PARTICULATE MATTER; PHYTOPLANKTON. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00102/21282/18891.pdf |
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| Delmas, R; Hafsaoui, M; Le Jehan, S; Queguiner, B; Treguer, P. |
| The fertilization of an eutrophic ecosystem of Western Europe (the Bay of Brest, 180 km super(2)) is observed from 1979 to 1982. Rich inputs in nutrients and dissolved organic matter flow into this semi-enclosed basin which waters are well mixed by the intensive action of tides. Natural and waste waters inputs are variable on a seasonal and annual scale; this induces large variations on the phytoplanktonic communities. This ecosystem presents high levels of primary production and low degree of maturity. By means of a model, the nitrate uptake by phytoplankton photosynthetic activity is simulated during spring 1980. |
| Tipo: Text |
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| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/00247/35802/34315.pdf |
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| Prego, R; Park, Yh; Barciela, Mc; Morvan, J; Poncin, J; Treguer, P. |
| The subantarctic frontal zone surveyed during the April-May 1991 SUZIL cruise in the Crozet-Kerguelen Amsterdam area shows a strong horizontal (north to south) gradient of dissolved silicate, increasing with depth, from 5 to 10 mu molSi kg(-1) at 100 m, and 10 to 70 mu molSi kg(-1) at 600 m. The northern limit of this frontal zone, which is formed by the confluence of the Subtropical and Subantarctic Fronts, is delimited at the surface by the 2 mu molSi kg(-1) silicate isoline. Silicate-salinity diagrams also allow different water regimes to be positioned relative to the frontal zone. This sloping interface is between two water bodies, one to the north with more saline subtropical waters of less concentrated silicate than the southern one, corresponding to... |
| Tipo: Text |
Palavras-chave: Silicate; Tracer; Frontal zone; Silicate-salinity diagram; Crozet Basin; Southern Ocean. |
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00239/35063/34593.pdf |
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