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Bec, Beatrice; Collos, Yves; Souchu, Philippe; Vaquer, Andre; Lautier, Jacques; Fiandrino, Annie; Benau, Laurent; Orsoni, Valerie; Laugier, Thierry. |
We explored the role of natural and anthropogenic environmental perturbations in shaping the community structure and dynamics of pico- and nanophytoplankton in coastal waters. The distribution patterns of phycoerythrin-rich picocyanobacteria (PE-CYAN) and phycocyanin-rich picocyanobacteria (PC-CYAN), autotrophic picoeukaryotes (PEUK) and nanophytoplankton (NANO) were examined over a period of 3 yr in 24 Mediterranean coastal lagoons displaying wide trophic gradients (from 0.2 to 630 mu g chlorophyll a [chl a] l(-1)) and salinity gradients (from fresh to marine waters). In summer, picoplanktonic abundances reached 3 x 10(8) cells l(-1), 5 x 10(9) cells l(-1) and 6 x 10(10) cells l(-1) for PE-CYAN, PC-CYAN and PEUK, respectively. PE-CYAN and PC-CYAN showed... |
Tipo: Text |
Palavras-chave: Autotrophic picoeukaryotes; Picocyanobacteria; Nanophytoplankton; Abundance; Biomass; Eutrophication; Mediterranean lagoons. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14267/11547.pdf |
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Morelle, Jerome; Schapira, Mathilde; Francoise, Sylvaine; Courtay, Gaelle; Orvain, Francis; Claquin, Pascal. |
In parallel to phytoplankton community dynamics, transparent exopolymeric particles (TEP) and exopolymeric substances (EPS) were investigated along the salinity gradient of a temperate estuary (Seine estuary, Normandy, France) over the course of a year. The phytoplankton community was mainly dominated by marine diatom species (especially Skeletonema sp., Nitzschia sp., and Paralia sulcata) associated with a spring bloom of pico-eukaryotes and the development of Cryptophyceae in summer. The decreases in species richness and salinity were correlated along the estuary and a significant exponential relationship between species richness and primary production was identified. Concentrations of TEP and EPS (soluble and bound carbohydrates) are highly dynamic in... |
Tipo: Text |
Palavras-chave: Picophytoplankton; Nanophytoplankton; Exopolymeric substances; Species richness. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00440/55189/56645.pdf |
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Ramírez-romero, Eduardo; Molinero, Juan-carlos; Sommer, Ulrich; Salhi, Noussaiba; Kéfi - Daly Yahia, Ons; Daly Yahia, Mohamed Néjib. |
Structural changes in plankton primary producers have large implications for food web dynamics, energy fluxes and the vertical export of biogenic particulate carbon. Here we examine phytoplankton data spanning the period 1993–2008 from the Bay of Tunis, southwestern Mediterranean Sea, in relation to long term hydroclimate variability. We show a conspicuous shift in the structure of the phytoplankton community characterized by an increase of small-sized species and diversity loss, revealing a dominance of smaller blooming diatoms and cyanobacteria. Such changes were concurrent with marked modifications in hydroclimatic patterns experienced in the Bay of Tunis consisting of a shift towards enhanced winter precipitation together with rising temperatures. This... |
Tipo: Text |
Palavras-chave: Size structural changes; Diversity loss; Ocean warming; Nanophytoplankton; Phytoplankton diversity; Southwestern mediterranean. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00602/71405/76566.pdf |
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Thomas, Y.; Garen, Pierre; Courties, C.; Charpy, L.. |
Spatial and temporal scales of variability in phyto- and bacterioplankton abundance were investigated in a deep atoll lagoon (Ahe, French Polynesia), Ahe Lagoon showed a classical phytoplankton composition, but its picophytoplankton (Prochlorococcus, Synechococcus and picoeukaryotes) concentrations are higher than the mean for Polynesian atoll lagoons. Phyto- and bacterioplankton descriptors were highly variable, with mean CVs of >20% in most cases: day night, day-to-day, vertical, lagoonal and seasonal. Phytoplankton biomass, which was estimated by in vivo fluorescence, was higher in the deep layer than in the upper layer. This pattern was detected on a day night scale, showing transitory vertical gradients, and through long-term events that were... |
Tipo: Text |
Palavras-chave: Flow cytometry; Picophytoplankton; Nanophytoplankton; Bacterioplankton; Vertical distribution; Day-to-day dynamics; Large-scale heterogeneity; Deep atoll lagoon; French Polynesia. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11425/7963.pdf |
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