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Auteur (up) Fouilland, E.; Mostajir, B.; Levasseur, M.; Roy, S.; Vidussi, F.; de Mora, S.; Demers, S.
Titre Effect of mixing on the structure of a natural plankton community: a mesocosm study Type Article scientifique
Année 2016 Publication Revue Abrégée Vie et Milieu
Volume 66 Numéro 3-4 Pages 251-259
Mots-Clés Accumulation; Composition; nitrogen; Phytoplankton Biomass; Phytoplankton Species; Structure Of The Pelagic Food Web; Transport Rates; turbulence; Vertical Mixing
Résumé A plankton community (< 202 μm) from the St. Lawrence Estuary was isolated

in four outdoor mesocosms with SLOW and fast mixing regimes. Variations in the concentrations

of nutrients, chlorophyll a (Chl a), nitrogen transport rates and plankton species composition

were monitored over a 10 day period. The vertical mixing times (Tm) for the slow and

fast mixing regimes were 180 and 60 min, corresponding to a vertical eddy diffusivity (Kv) of

2.34 and 7.03 cm2 s–1, respectively. The different mixing regimes had a strong effect on the

physiology of the phytoplankton and the specific structure of the plankton assemblage. The

Slow mixing regime stimulated the development of a mixed community of flagellates, small

diatoms and proto-metazooplankton while the fast mixing regime triggered the development

of a large diatom-dominated community with lower abundances of proto-metazooplankton. At

the end of the 10 day experiment, the Chl a concentrations were 50 % higher in the mesocosms

with the fast mixing regime than in those with the slow mixing regime. These results indicate

that, under low nutrient conditions, higher turbulence gives a competitive advantage to diatoms

and decreases the zooplankton grazing pressure, resulting in net positive growth. Extrapolation

of these results to natural systems suggests that a wind-driven mixing event may increase

the net phytoplankton biomass production of a stratified water column, even if there is no external

input of nutrients.
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Numéro d'Appel MARBEC @ alain.herve @ collection 2082
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Auteur (up) Fournier, J.; Dupuy, C.; Bouvy, M.; Couraudon-Réale, M.; Charpy, L.; Pouvreau, S.; Le Moullac, G.; Le Pennec, M.; Cochard, J.-C.
Titre Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia) Type Article scientifique
Année 2012 Publication Revue Abrégée Marine Pollution Bulletin
Volume 65 Numéro 10–12 Pages 490-499
Mots-Clés Clearance rates; French Polynesia; Pinctada margaritifera; Protists; phytoplankton
Résumé
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Volume de collection Numéro de collection Edition
ISSN 0025-326x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 770
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Auteur (up) Garrido, M.; Cecchi, P.; Collos, Y.; Agostini, S.; Pasqualini, V.
Titre Water flux management and phytoplankton communities in a Mediterranean coastal lagoon. Part I: How to promote dinoflagellate dominance? Type Article scientifique
Année 2016 Publication Revue Abrégée Marine Pollution Bulletin
Volume 104 Numéro 1–2 Pages 139-152
Mots-Clés Biguglia, Eutrophication; Mediterranean coastal lagoon; Phytoplankton; Prorocentrum minimum; Water management
Résumé The Biguglia lagoon is a shallow Mediterranean coastal ecosystem where eutrophication is increasing for years. A channel supplying freshwater was cleared in 2009 to enhance lagoon water circulation and alleviate dystrophic crises. Monthly monitoring was started in 2010 to document the impacts of this action on abiotic characteristics and phytoplankton communities. Three stations were surveyed (by microscopy and HPLC). Evidence suggests that this operation had an unexpected outcome. Salinity footprints indicated the succession of three main hydrological sequences that depended on rainfall and circulation pattern. Diatoms and dinoflagellates dominated the first sequence, characterized by heavy rainfall, while Prorocentrum minimum became progressively the dominant species in the second period (increasing salinities) with extensive bloom over the whole lagoon (5.93 × 10-5 cells·L− 1) during the third period. These phytoplankton successions and community structures underline the risk of pernicious effects arising from remediation efforts, in the present case based on increasing freshwater inputs.
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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0025-326x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1525
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Auteur (up) Garrido, M.; Cecchi, P.; Malet, N.; Bec, B.; Torre, F.; Pasqualini, V.
Titre Evaluation of FluoroProbe® performance for the phytoplankton-based assessment of the ecological status of Mediterranean coastal lagoons Type Article scientifique
Année 2019 Publication Revue Abrégée Environ Monit Assess
Volume 191 Numéro 4 Pages 204
Mots-Clés FluoroProbe®; Hplc; Mediterranean coastal lagoons; Monitoring; Phytoplankton
Résumé The European Water Framework Directive and several other legislations worldwide have selected phytoplankton for monitoring the ecological status of surface waters. This assessment is a complicated task in coastal lagoons due to their intrinsic variability, prompting moves to use real-time measurements. Here, we tested the ability of the submersible spectrofluorometer FluoroProbe® to accurately estimate the phytoplankton biomass and to efficiently discriminate spectral groups in Mediterranean coastal lagoons, by using sub-surface water samples (n = 107) collected at Biguglia lagoon (Corsica) in different environmental situations (salinity and trophic state) from March 2012 to December 2014. We compared the estimates of biomass and phytoplankton group composition obtained with the FluoroProbe® (in situ and lab measurements) with the spectrofluorimetrically measured biomass and HPLC-derived quantifications of pigment concentrations. FluoroProbe® provided good estimates of the total phytoplankton biomass (particularly, the lab measurements). The FluoroProbe® data were significantly correlated with the HPLC results, except for the in situ measurements of very weak concentrations of blue-green and red algae. Our findings indicate that factory-calibrated FluoroProbe® is an efficient and easy-to-use real-time phytoplankton monitoring tool in coastal lagoons, especially as an early warning system for the detection of potentially harmful algal blooms. Practical instructions dedicated to non-specialist field operators are provided. A simple and efficient method for discarding in situ measurement outliers is also proposed.
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Volume de collection Numéro de collection Edition
ISSN 1573-2959 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2527
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Auteur (up) Garrido, M.; Cecchi, P.; Vaquer, A.; Pasqualini, V.
Titre Effects of sample conservation on assessments of the photosynthetic efficiency of phytoplankton using PAM fluorometry Type Article scientifique
Année 2013 Publication Revue Abrégée Deep-Sea Res. Part I-Oceanogr. Res. Pap.
Volume 71 Numéro Pages 38-48
Mots-Clés diatom, quantum yield, temperature, parameters; PAM fluorescence, Phytoplankton, Temperature Biguglia lagoon; physiological-responses, marine-phytoplankton, oxygen evolution, benthic; rapid light curves, chlorophyll-a fluorescence, in-vivo,
Résumé Pulse Amplitude Modulated (PAM) fluorometry is now a widely used method for the assessment of phytoplankton fitness, with an increasing popularity in field assessments. It is usually recommended to carry out measurements swiftly after collection, but the number of samples and analytical procedures needed to obtain valuable datasets sometimes makes immediate analysis impracticable, forcing delays between fluorescence measurements. Conservation conditions of samples before analysis may potentially affect their photosynthetic performances but no formal study documenting such impacts appears available in the literature. The aim of this study was to investigate the effects of storage conditions (temperature, duration) on photosynthetic parameters in different phytoplankton communities (characterized in situ by a BBE fluoroprobe) sampled during summer in different environmental locations in a Mediterranean lagoon (Biguglia lagoon, Corsica, France). PAM-fluorescence parameters were measured after three different conservation durations (2-4 h, 6-8 h and 10-12 h after collection) on samples stored at three different temperatures (15 degrees C, 25 degrees C and 35 degrees C). Results showed that storage at the highest temperature severely impacted photosynthetic parameters, with cumulative effects as storage duration increased. For phytoplankton samples collected in warm or tropical environments, storage at “room temperature” (25 degrees C) only appeared a valid option if measurements have to be carried out strictly within a very short delay. Inversely, cooling the samples (i.e. conservation at 15 degrees C) did not induce significant effects, independently of storage duration. Cooling appeared the best solution when sampling-to-analysis delay goes over a few hours. Long-term storage ( > 8 h) should definitively be avoided. (C) 2012 Elsevier Ltd. All rights reserved.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0967-0637 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 552
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