46 results on '"Roques, Cécile"'
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2. Do microbial planktonic communities reflect the ecological changes of Glorieuses coral reefs (Iles Eparses, Western Indian Ocean)?
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Bouvy, Marc, Bélières, Alice, Carré, Claire, Got, Patrice, Pagano, Marc, Agogué, Hélène, Bec, Béatrice, Roques, Cécile, Bigot, Lionel, Chabanet, Pascale, and Dupuy, Christine
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- 2022
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3. Duality of trophic supply and hydrodynamic connectivity drives spatial patterns of Pacific oyster recruitment
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Lagarde, Franck, Fiandrino, Annie, Ubertini, Martin, d’Orbcastel, Emmanuelle Roque, Mortreux, Serge, Chiantella, Claude, Bec, Béatrice, Bonnet, Delphine, Roques, Cécile, Bernard, Ismaël, Richard, Marion, Guyondet, Thomas, Pouvreau, Stéphane, and Lett, Christophe
- Published
- 2019
4. Heterogeneity of Japanese Oyster (Crassostrea Gigas) Spat Collection in a Shellfish Farmed Mediterranean Lagoon
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Lagarde, Franck, Ubertini, Martin, Mortreux, Serge, Perignon, Adeline, Leurion, Axel, Le Gall, Patrik, Chiantella, Claude, Meddah, Slem, Guillou, Jean-Louis, Messiaen, Grégory, Bec, Béatrice, Roques, Cécile, Bonnet, Delphine, Cochet, Hélène, Bernard, Ismaël, Gervasoni, Erika, Richard, Marion, Miron, Gilles, Fiandrino, Annie, Pouvreau, Stéphane, Roque D’orbcastel, Emmanuelle, Komatsu, Teruhisa, editor, Ceccaldi, Hubert-Jean, editor, Yoshida, Jiro, editor, Prouzet, Patrick, editor, and Henocque, Yves, editor
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- 2019
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5. Control of the pH for marine microalgae polycultures: A key point for CO2 fixation improvement in intensive cultures
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Galès, Amandine, Triplet, Sébastien, Geoffroy, Thibault, Roques, Cécile, Carré, Claire, Le Floc’h, Emilie, Lanfranchi, Mélissa, Simier, Monique, Roque d’Orbcastel, Emmanuelle, Przybyla, Cyrille, and Fouilland, Eric
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- 2020
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6. Co-occurrence networks reveal the central role of temperature in structuring the plankton community of the Thau Lagoon
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Trombetta, Thomas, Vidussi, Francesca, Roques, Cécile, Mas, Sébastien, Scotti, Marco, and Mostajir, Behzad
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- 2021
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7. Trophic environments influence size at metamorphosis and recruitment performance of Pacific oysters
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Lagarde, Franck, Richard, Marion, Bec, Béatrice, Roques, Cécile, Mortreux, Serge, Bernard, Ismaël, Chiantella, Claude, Messiaen, Gregory, Nadalini, Jean-Baptiste, Hori, Masakazu, Hamaguchi, Masami, Pouvreau, Stéphane, d’Orbcastel, Emmanuelle Roque, and Tremblay, Réjean
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- 2018
8. Recruitment of the Pacific oyster Crassostrea gigas in a shellfish-exploited Mediterranean lagoon : discovery, driving factors and a favorable environmental window
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Lagarde, Franck, d’orbcastel, Emmanuelle Roque, Ubertini, Martin, Mortreux, Serge, Bernard, Ismaël, Fiandrino, Annie, Chiantella, Claude, Bec, Béatrice, Roques, Cécile, Bonnet, Delphine, Miron, Gilles, Richard, Marion, Pouvreau, Stéphane, and Lett, Christophe
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- 2017
9. A trade-off between mucocytes and bacteriocytes in Loripes orbiculatus gills (Bivalvia, Lucinidae): a mixotrophic adaptation to seasonality and reproductive status in a symbiotic species?
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Roques, Cécile, Grousset, Evelyse, Troussellier, Marc, Hermet, Sophie, Le Carrer, Johan, Sar, Chamroeun, and Caro, Audrey
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- 2020
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10. Failure of bivalve foundation species recruitment related to trophic changes during an extreme heatwave event
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Correia-Martins, Alana, Tremblay, Réjean, Bec, Béatrice, Roques, Cécile, Atteia, Ariane, Gobet, Angélique, Richard, Marion, Hamaguchi, Masami, Miyajima, Toshihiro, Hori, Masakazu, Miron, Gilles, Pouvreau, Stéphane, Lagarde, Franck, Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Saga University [Japon], Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
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Extreme heatwave ,Bivalves ,Ecology ,[SDE.MCG]Environmental Sciences/Global Changes ,Reproduction ,Aquatic Science ,Cascade of environmental effects ,Larval ecology ,Phenology ,Crassostrea gigas ,Trophic changes ,Climate change ,Pacific oyster ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Ecology, Evolution, Behavior and Systematics - Abstract
Bivalves are regulators of coastal lagoons and provide a wide range of ecosystem services. However, coastal lagoons are sensitive to climate change. Our objective was to describe the drivers of the cascade of ecological events that occurred during a summer heatwave and which resulted in recruitment failure of the Pacific oyster Crassostrea gigas. Results show that elevated temperatures and salinity caused a shift in planktonic food availability toward smaller taxa. These trophic changes did not affect food accumulation by oyster larvae or their fatty acid composition but did affect post-metamorphosis success, with up to 24% fewer young metamorphosed postlarvae at some sites and no development of juveniles at all sites. This resulted in the failure of oyster recruitment and in the development of tubeworms, a trophic and spatial competitor that can better ingest small particles. This knowledge suggests that, in the context of marine heatwaves, the ecological limits of oyster larvae are narrower than their physiological limits.
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- 2022
11. Impact of anoxia and oyster mortality on nutrient and microbial planktonic components: A mesocosm study
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Le Ray, Julie, primary, Bec, Béatrice, additional, Fiandrino, Annie, additional, Lagarde, Franck, additional, Cimiterra, Nicolas, additional, Raimbault, Patrick, additional, Roques, Cécile, additional, Rigaud, Sylvain, additional, Régis, Julie, additional, Mostajir, Behzad, additional, Mas, Sébastien, additional, and Richard, Marion, additional
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- 2023
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12. Microbial food web structural and functional responses to oyster and fish as top predators
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Mostajir, Behzad, Roques, Cécile, Bouvier, Corinne, Bouvier, Thierry, Fouilland, Éric, Got, Patrice, Le Floc’h, Emilie, Nouguier, Jean, Mas, Sébastien, Sempéré, Richard, Sime-Ngando, Télesphore, Troussellier, Marc, and Vidussi, Francesca
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- 2015
13. Simultaneous Study of the Growth and Grazing Mortality Rates of Microbial Food Web Components in a Mediterranean Coastal Lagoon
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Pecqueur, David, Courboulès, Justine, Roques, Cécile, Mas, Sébastien, Pete, Romain, Vidussi, Francesca, Mostajir, Behzad, Pecqueur, David, Courboulès, Justine, Roques, Cécile, Mas, Sébastien, Pete, Romain, Vidussi, Francesca, and Mostajir, Behzad
- Abstract
The abundances of 17 cytometric groups encompassing four groups of bacteria, three groups of cyanobacteria, six groups of eukaryotic picophytoplankton (<2–3 µm), and four groups of small eukaryotic nanophytoplankton (between 3 and 6 µm) were studied in the Thau Lagoon across different seasonal conditions. Among them, the growth (µ) and mortality rates due to grazing (g) of 12 groups of bacteria, cyanobacteria, and eukaryotic pico- and nanophytoplankton were simultaneously studied in the Thau Lagoon via four dilution experiments across different seasonal conditions. The abundances of heterotrophic flagellates and ciliates and their potential predators were studied and linked to prey mortality. Bacteria were more active than phytoplankton and displayed the highest growth and grazing mortality rates. Most studied groups had g:µ ratios > 1, suggesting that predators efficiently grazed and transferred these preys. Surprisingly, the observed variations in predator abundance across seasons did not necessarily correspond with changes in grazing pressure. The significant positive relationship found between water temperature and bacterial grazing mortality rates and the reverse trend observed for larger eukaryotic prey suggested that warmer water increases small prokaryote transfer to higher trophic levels but disadvantages larger eukaryotic prey transfer.
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- 2022
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14. Epibiotic bacterial community of Sphaeroma serratum (Crustacea, Isopoda) : relationship with molt status
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Caro, Audrey, Escalas, Arthur, Bouvier, Corinne, Grousset, Evelyse, Lautredou-Audouy, Nicole, Roques, Cécile, Charmantier, Mireille, and Gros, Olivier
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- 2012
15. Simultaneous Study of the Growth and Grazing Mortality Rates of Microbial Food Web Components in a Mediterranean Coastal Lagoon
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Pecqueur, David, primary, Courboulès, Justine, additional, Roques, Cécile, additional, Mas, Sébastien, additional, Pete, Romain, additional, Vidussi, Francesca, additional, and Mostajir, Behzad, additional
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- 2022
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16. Effects of experimental warming and increased ultraviolet B radiation on the Mediterranean plankton food web
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Vidussi, Francesca, Mostajir, Behzad, Fouilland, Eric, Le Floc’h, Emilie, Nouguier, Jean, Roques, Cécile, Got, Patrice, Thibault-Botha, Delphine, Bouvier, Thierry, and Troussellier, Marc
- Published
- 2011
17. Phénomène d’Eaux Vertes à Picochlorum en lagune de Thau pendant les années 2018 et 2019. Observations environnementales
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Lagarde, Franck, Atteia Van Lis, Ariane, Gobet, Angelique, Richard, Marion, Mostajir, Behzad, Roques, Cécile, Foucault, Elodie, Messiaen, Gregory, Hubert, Clarisse, Cimiterra, Nicolas, Derolez, Valerie, and Bec, Beatrice
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Malaïgue ,Aphelidium-like ,Climate Change ,Climate Variability ,Thau Lagoon ,Variabilité Climatique ,Green Water Phenomenon ,Cascade d’Effets ,Evènements Extrêmes ,Changement Climatique ,Anoxia ,Extreme Events ,Canicule Marine ,Cascading Effects ,Changement de Communautés Phytoplanctoniques ,Eaux Vertes ,Phytoplankton Community Change ,Picochlorum ,Marine Heatwave ,Réchauffement ,Warming ,Lagune de Thau ,Anoxie - Abstract
After having been eutrophied until the 2000s, the Thau lagoon has been now on an ecological restoration trajectory according to the oligotrophisation process. However, 2018 appeared to be a turning point in its ecological functioning due to its disturbed hydroclimatic context with the appearance of an unprecedented phenomenon of green water significantly impacting the oyster farming sector in its productivity and socio-economy. Already described in the 1980s in the Leucate lagoon, this phenomenon had never been observed in Thau and the need to observe in order to understand led to the carrying out of environmental monitoring from January 2019 to January 2020 on 3 stations. The description of the spatio-temporal dynamics of phytoplankton and of the species causing green water was associated with the biogeochemistry of lagoon waters (nitrogen, phosphorus and silicate nutrients) and the dynamics of autotrophic and heterotrophic eukaryotic communities. This monitoring was completed by a diagnosis of macrophytes (including macroalgae and seagrass beds) carried out in 2019 in order to measure the impact of disturbances on this compartment. The hypothesis of a link between the remarkable hydroclimatic context of 2018 and this green water phenomenon was put forward. Our results showed that the hydroclimatic context of the Thau Basin has evolved with a trend towards an increase in annual average water temperatures (+1.6°C over 20 years between 2000 and 2019), with an increase in annual average salinities (+2 PSU between 2000 and 2019) and more intense periods of oversalinity (up to 110 days in 2012 and maximums of 42.9 in 2016). Winter storms, spring thunderstorms, summer heatwave, anoxy and autumn Mediterranean episodes of intense precipitation make 2018 an atypical year. This succession of extreme events resulted in the phenomenon of green water. This project helped to find the origin: a bloom of Picochlorum, a picophytoplankton known to be thermotolerant and halotolerant. Picochlorum dominated the phytoplankton from December 2018 to April 2019 followed by minor developments until August 2019. The return to more typical phytoplankton communities occurred in September 2019 until the end of monitoring in February 2020. This bloom could be linked to massive inputs of nitrogen and phosphate nutrients linked successively to heavy rainfall in spring, to the summer anoxy and to the autumn rainfall of the Mediterranean episodes. The population dynamics of Picochlorum was controlled by nutrients but probably also by a parasitoid predator of the Aphelidium type that was identified in a preliminary way. The precise identification of this parasitoid remains a prospect. The impacts of the malaigue and green water phenomena on the macrophytes have led to a decrease in the total macrophyte cover. The relative cover of reference species, such as eelgrass, has also decreased, with a greater impact on the western part of the basin. The extreme hydroclimatic events of 2018 induced a cascade of ecological effects with changes in phytoplankton communities. It took one year after the 2018 anoxy to return to the previous state, as in the case of the green waters of the Leucate lagoon in the 1980s. Mediterranean lagoon systems represent high-stakes areas with ecological, environmental, societal and economic issues. The ecological restoration of Mediterranean lagoons and the associated goods and services requires an understanding of the dynamics of the various physical, chemical, biological and societal compartments, in order to support the marine culture sectors and anticipate their future trajectories, particularly in a context of anthropisation and global change., Après avoir été eutrophisée jusque dans les années 2000, la lagune de Thau est depuis sur une trajectoire de restauration écologique selon le processus d’oligotrophisation. Cependant, l’année 2018 est apparue comme une année de bascule dans son fonctionnement écologique par son contexte hydroclimatique perturbé avec l’apparition d’un phénomène inédit d’eaux vertes impactant significativement la filière ostréicole dans sa productivité et sa socio-économie. Déjà décrit dans les années 1980 dans la lagune de Leucate, ce phénomène n’avait jamais été observé dans Thau et le besoin d’observer pour comprendre a abouti à la réalisation d’un suivi environnemental de janvier 2019 à janvier 2020 sur 3 stations. La description de la dynamique spatio-temporelle du phytoplancton et de l’espèce à l’origine d’eaux vertes a été associée à la biogéochimie des eaux lagunaires (nutriments azotés, phosphorés et silicatés) et à la dynamique des communautés eucaryotes autotrophes et hétérotrophes. Ce suivi a été complété par un diagnostic des macrophytes (incluant les macroalgues et les herbiers) réalisé en 2019 afin de mesurer l’impact des perturbations sur ce compartiment. L’hypothèse du lien entre le contexte hydroclimatique remarquable de l’année 2018 et ce phénomène d’eaux vertes a été posée. Nos résultats ont montré que le contexte hydroclimatique du bassin de Thau a évolué avec une tendance à l’augmentation des moyennes annuelles de températures de l’eau (+1.6°C sur 20 ans entre 2000 et 2019), avec l’augmentation des moyennes annuelles de salinités (+2 PSU entre 2000 et 2019) et des périodes de sursalinités plus intenses (jusqu’à 110 jours en 2012 et des maximums à 42,9 en 2016). Les tempêtes hivernales, les orages printaniers, la canicule estivale, la malaïgue et les épisodes méditerranéens automnaux de précipitations intenses font de l’année 2018, une année atypique. Cette succession d’évènements extrêmes a eu pour conséquence le phénomène d’eaux vertes. Ce projet a permis d’en trouver l’origine : une efflorescence de Picochlorum, picophytoplancton connu pour être thermotolérant et halotolérant. Picochlorum a dominé le phytoplancton de décembre 2018 à avril 2019 suivi de développements mineurs jusqu’en aout 2019. Le retour à des communautés phytoplanctoniques plus typiques s’est fait en septembre 2019 jusqu’à la fin du suivi en février 2020. Cette efflorescence a pu être reliée à des apports massifs en nutriments azotés et phosphatés liés successivement à des précipitations fortes au printemps, à la malaïgue estivale et aux précipitations automnales des épisodes méditerranéens. La dynamique de population du Picochlorum a été contrôlée par les nutriments mais probablement aussi par un prédateur parasitoïde de type Aphelidium identifié de façon préliminaire. L’identification précise de ce parasitoïde reste une perspective. Les impacts des phénomènes de malaïgue et d’eaux vertes sur les macrophytes ont induit une diminution du recouvrement total en macrophytes. Le recouvrement relatif en espèce de référence, comme les zostères, a également diminué avec un impact plus important sur la partie ouest du bassin. Les évènements extrêmes hydroclimatiques de 2018 ont induit une cascade d’effets écologiques avec changement de communautés phytoplanctoniques. Il aura fallu une année après la malaïgue de 2018 pour voir le retour à l’état antérieur, comme dans le cas des eaux vertes de la lagune de Leucate dans les années 1980. Les systèmes lagunaires méditerranéens représentent des zones à forts enjeux avec des problématiques écologiques, environnementales, sociétales et économiques. La restauration écologique des lagunes méditerranéennes et des biens et services associés nécessite de comprendre la dynamique des différents compartiments physiques, chimiques, biologiques et sociétaux, pour accompagner les filières des cultures marines et d’anticiper leurs trajectoires futures, en particulier dans un contexte d’anthropisation et de changement global.
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- 2021
18. Pelagic population dynamics of Aurelia sp. in French Mediterranean lagoons
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Marques, Raquel, Albouy-Boyer, Séverine, Delpy, Floriane, Carré, Claire, Le Flocʼh, Émilie, Roques, Cécile, Molinero, Juan-Carlos, and Bonnet, Delphine
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- 2015
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19. Environmental drivers of plankton communities in coastal waters: the central role of temperature revealed by co-occurrence networks
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Trombetta, Thomas, primary, Vidussi, Francesca, additional, Roques, Cécile, additional, Mas, Sébastien, additional, Scotti, Marco, additional, and Mostajir, Behzad, additional
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- 2021
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20. Rapid responses of pristine marine planktonic communities in experimental approach to diuron and naphthalene (Juan de Nova Island, Western Indian Ocean)
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Bouvy, Marc, Dupuy, Christine, Got, Patrice, Domaizon, Isabelle, Carré, Claire, Pagano, Marc, Debroas, Didier, Roques, Cécile, Leboulanger, Christophe, Bouvy, Marc, Dupuy, Christine, Got, Patrice, Domaizon, Isabelle, Carré, Claire, Pagano, Marc, Debroas, Didier, Roques, Cécile, and Leboulanger, Christophe
- Abstract
Planktonic communities from Juan de Nova lagoon were submitted to a single exposure of diuron or naphthalene in triplicate outdoor 40-L mesocosms for 5 days. The study followed the temporal changes of the assemblages by determining abundances and taxonomic level of microbial (heterotrophic prokaryotes, picocyanobacteria, heterotrophic protists and phytoplankton) and metazooplankton communities. Exposure to both contaminants did not result in significant changes in phytoplankton abundances. Microscopic identification demonstrated the dominance of Bacillariophyta (mostly Chaetoceros tenuissimus) accounting for more than 95% of the microalgae detected in all mesocosms. Using 18S rRNA metabarcoding, temporal changes in the proportion of eukaryotic operational taxonomic units (OTUs) were highlighted for most taxonomic groups. Diuron had no significant effect on the abundance of eukaryotic picoheterotrophs, ciliates, whereas naphthalene had a significant positive effect on heterotrophic prokaryotes. Metazooplankton was not significantly modified under contaminant exposure, except for copepods nauplii in presence of diuron. Multivariate analysis indicated significant responses of communities linked to the experimental time and conditions. The analysis also revealed a modification of the trophic relationships among communities over time, from a dominant multivorous food web after 48 h towards a reduced microbial loop after 120 h of experiment time.
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- 2021
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21. Bacterial carbon dependence on freshly produced phytoplankton exudates under different nutrient availability and grazing pressure conditions in coastal marine waters
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Fouilland, Eric, Tolosa, Imma, Bonnet, Delphine, Bouvier, Corinne, Bouvier, Thierry, Bouvy, Marc, Got, Patrice, Le Flocʼh, Emilie, Mostajir, Behzad, Roques, Cécile, Sempéré, Richard, Sime-Ngando, Télesphore, and Vidussi, Francesca
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- 2014
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22. Marine Microbial Food Web Networks During Phytoplankton Bloom and Non-bloom Periods: Warming Favors Smaller Organism Interactions and Intensifies Trophic Cascade
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Trombetta, Thomas, Vidussi, Francesca, Roques, Cécile, Scotti, Marco, Mostajir, Behzad, Trombetta, Thomas, Vidussi, Francesca, Roques, Cécile, Scotti, Marco, and Mostajir, Behzad
- Abstract
Microbial food web organisms are at the base of the functioning of pelagic ecosystems and support the whole marine food web. They are very reactive to environmental changes and their interactions are modified in response to different productive periods such as phytoplankton bloom and non-bloom as well as contrasted climatic years. To study ecological associations, identify potential interactions between microorganisms and study the structure of the microbial food web in coastal waters, a weekly monitoring was carried out in the Thau Lagoon on the French Mediterranean coast. The monitoring lasted from winter to late spring during two contrasting climatic years, a typical Mediterranean (2015) and a year with an extreme warm winter (2016). Correlation networks comprising 110 groups/taxa/species were constructed to characterize potential possible interactions between the microorganisms during bloom and non-bloom periods. Complex correlation networks during the bloom and dominated by negative intraguild correlations and positive correlations of phytoplankton with bacteria. Such pattern can be interpreted as a dominance of competition and mutualism. In contrast, correlation networks during the non-bloom period were less complex and mostly dominated by tintinnids associations with bacteria mostly referring to potential feeding on bacteria, which suggests a shift of biomass transfer from phytoplankton-dominated food webs during bloom to more bacterioplankton-based food webs during non-bloom. Inter-annual climatic conditions significantly modified the structure of microbial food webs. The warmer year favored relationships among smaller group/taxa/species at the expense of large phytoplankton and ciliates, possibly due to an intensification of the trophic cascade with a potential shift in energy circulation through microbial food web. Our study compares a typical Mediterranean spring with another mimicking the prospected intensification of global warming; if such consideratio
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- 2020
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23. Rapid responses of pristine marine planktonic communities in experimental approach to diuron and naphthalene (Juan de Nova Island, Western Indian Ocean)
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Bouvy, Marc, primary, Dupuy, Christine, additional, Got, Patrice, additional, Domaizon, Isabelle, additional, Carré, Claire, additional, Pagano, Marc, additional, Debroas, Didier, additional, Roques, Cécile, additional, and Leboulanger, Christophe, additional
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- 2021
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24. Marine Microbial Food Web Networks During Phytoplankton Bloom and Non-bloom Periods: Warming Favors Smaller Organism Interactions and Intensifies Trophic Cascade
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Trombetta, Thomas, primary, Vidussi, Francesca, additional, Roques, Cécile, additional, Scotti, Marco, additional, and Mostajir, Behzad, additional
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- 2020
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25. Trophic ecology of a blooming jellyfish (Aurelia coerulea) in a Mediterranean coastal lagoon
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Marques, Raquel, primary, Bonnet, Delphine, additional, Carré, Claire, additional, Roques, Cécile, additional, and Darnaude, Audrey M., additional
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- 2020
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26. Distribution and dynamics of microbial communities in a thalassohaline crater lake (Dziani Dzaha , Mayotte)
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Got, Patrice, Bouvy, Marc, Roques, Cécile, Bernard, Cécile, Leboulanger, Christophe, Ader, Magali, Sarazin, Gérard, Jézéquel, Didier, Hugoni, Mylène, Agogué, Hélène, and Troussellier, Marc
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- 2019
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27. Chapitre III. Le couple dispositif/pratique dans les échanges interpersonnes
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Després-Lonnet, Marie, primary, Gentes, Annie, additional, Moreau, Émilie, additional, and Roques, Cécile, additional
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- 2003
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28. Importance of ecological interactions during wastewater treatment using High Rate Algal Ponds under different temperate climates
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Galès, Amandine, Bonnafous, Anaïs, Carré, Claire, Jauzein, Vincent, Lanouguère, Elodie, Le Floc'H, Emilie, Pinoit, Joanna, Poullain, Clothilde, Roques, Cécile, Sialve, Bruno, Simier, Monique, Steyer, Jean-philippe, Fouilland, Eric, Galès, Amandine, Bonnafous, Anaïs, Carré, Claire, Jauzein, Vincent, Lanouguère, Elodie, Le Floc'H, Emilie, Pinoit, Joanna, Poullain, Clothilde, Roques, Cécile, Sialve, Bruno, Simier, Monique, Steyer, Jean-philippe, and Fouilland, Eric
- Abstract
Several studies focused on wastewater treatment in High Rate Algal Ponds (HRAP) suggest that highly variable climatic conditions cause large variations of microalgal biomass productivity. In the present study, we show that similar carbon, nitrogen and phosphorus removal efficiencies were reached in different HRAPs treating urban wastewaters located in two different temperate (Mediterranean and oceanic) climates. Furthermore, similar ecological successions were observed in these HRAPs. During the start-up phase, the consumption of organic matter by detritivores, already present in the wastewater, appears to be necessary for the microalgae to grow within two weeks in spring. The growth of the rapid-growing species, Chlorella sp., followed by the grazing-resilient species, Scenedesmus sp., combined with nitrifying and denitrifying bacterial activity, removed most the ammonia. The resulting exhaustion of ammonia would limit the complete removal of dissolved COD by bacteria and phosphate by microalgae in the HRAPs. This study shows that similar biological and environmental constraints were applied on the HRAPs, making the process efficiency highly reproducible under different temperate latitudes.
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- 2019
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29. The complete methylome of an entomopathogenic bacterium reveals the existence of loci with unmethylated Adenines
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Payelleville, Amaury, Legrand, Ludovic, Ogier, Jean-Claude, Roques, Cécile, Roulet, Alain, Bouchez, Olivier, Mouammine, Annabelle, Givaudan, Alain, Brillard, Julien, Diversité, Génomes & Interactions Microorganismes - Insectes [Montpellier] (DGIMI), Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM), Laboratoire des interactions plantes micro-organismes (LIPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), GeT PlaGe, Genotoul, Institut National de la Recherche Agronomique (INRA), Department of Fundamental Microbiology, Faculty of Biology and Medicine, Université de Lausanne (UNIL), INRA Plant Health and Environment (SPE) division : SPE2015-65359, SPE-IB17-DiscriMet, GAIA doctoral school : 584, Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Génome et Transcriptome - Plateforme Génomique (GeT-PlaGe), Institut National de la Recherche Agronomique (INRA)-Plateforme Génome & Transcriptome (GET), Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3)
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DNA, Bacterial ,Site-Specific DNA-Methyltransferase (Adenine-Specific) ,Insecta ,entomopathogenic bacteria ,lcsh:Medicine ,régulation génétique ,Article ,regulator gene ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Animals ,Nucleotide Motifs ,lcsh:Science ,Promoter Regions, Genetic ,bactérie entomopathogène ,photorhabdus luminescens ,différenciation cellulaire ,Vegetal Biology ,Whole Genome Sequencing ,méthylation de l'ADN ,Adenine ,lcsh:R ,Microbiology and Parasitology ,prokaryote ,Gene Expression Regulation, Bacterial ,DNA Methylation ,Microbiologie et Parasitologie ,Eukariota ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,Genetic Loci ,lcsh:Q ,Photorhabdus ,Genome, Bacterial ,Biologie végétale - Abstract
DNA methylation can serve to control diverse phenomena in eukaryotes and prokaryotes, including gene regulation leading to cell differentiation. In bacteria, DNA methylomes (i.e., methylation state of each base of the whole genome) have been described for several species, but methylome profile variation during the lifecycle has rarely been studied, and only in a few model organisms. Moreover, major phenotypic changes have been reported in several bacterial strains with a deregulated methyltransferase, but the corresponding methylome has rarely been described. Here we report the first methylome description of an entomopathogenic bacterium, Photorhabdus luminescens. Eight motifs displaying a high rate of methylation (>94%) were identified. The methylome was strikingly stable over course of growth, but also in a subpopulation responsible for a critical step in the bacterium’s lifecycle: successful survival and proliferation in insects. The rare unmethylated GATC motifs were preferentially located in putative promoter regions, and most of them were methylated after Dam methyltransferase overexpression, suggesting that DNA methylation is involved in gene regulation. Our findings bring key insight into bacterial methylomes and encourage further research to decipher the role of loci protected from DNA methylation in gene regulation.
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- 2018
30. Importance of ecological interactions during wastewater treatment using High Rate Algal Ponds under different temperate climates
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Galès, Amandine, primary, Bonnafous, Anaïs, additional, Carré, Claire, additional, Jauzein, Vincent, additional, Lanouguère, Elodie, additional, Le Floc'h, Emilie, additional, Pinoit, Joanna, additional, Poullain, Clothilde, additional, Roques, Cécile, additional, Sialve, Bruno, additional, Simier, Monique, additional, Steyer, Jean-Philippe, additional, and Fouilland, Eric, additional
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- 2019
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- View/download PDF
31. Trophic ecology of a blooming jellyfish (Aurelia coerulea) in a Mediterranean coastal lagoon.
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Marques, Raquel, Bonnet, Delphine, Carré, Claire, Roques, Cécile, and Darnaude, Audrey M.
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JELLYFISHES ,CRASSOSTREA ,MARINE zooplankton ,PACIFIC oysters ,ISOTOPIC signatures ,ECOLOGY ,COMPETITION (Biology) ,LAGOONS - Abstract
The current lack of knowledge on the trophic ecology of scyphozoans, particularly at the benthic stage, prevents a full understanding of the controls on many jellyfish blooms. The blooming scyphozoan (Aurelia coerulea) completes its entire life cycle in the Thau lagoon (southern France), where the annual population dynamics of both its benthic and pelagic stages have been described. This offered an exceptional framework to investigate the trophic processes regulating jellyfish populations over time. To this aim, stable isotopic signature analysis (δ13C and δ15N) was used to infer the diet of both A. coerulea scyphistomae and medusae over 1 year. These results were matched with medusae gut content analysis and with the monthly abundances of local plankton groups. Lastly, the isotopic signatures of A. coerulea scyphistomae and medusae were compared with those of the oysters (Crassostrea gigas) cultivated in the lagoon to evaluate the potential interspecific trophic competition. The results revealed two seasonal shifts in the trophic niche of A. coerulea and substantial overlap between the diets of its benthic and pelagic stages. Conversely, trophic niche overlaps with the oysters were restricted, suggesting a limited impact of the local jellyfish bloom on shellfish production. Phytoplankton, microzooplankton, mesozooplankton, and sedimentary organic matter were all important food sources during critical periods of A. coerulea life‐cycle. However, microzooplankton abundance was found to be key for the production of buds by the scyphistomae and, therefore it is likely to control the benthic population size and, thereby, to modulate the intensity of its annual bloom in Thau. [ABSTRACT FROM AUTHOR]
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- 2021
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32. The role played by predators in a high rate algal pond for wastewater treatment
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Martínez, Carlos, Fouilland, Eric, Galès, Amandine, Roques, Cécile, Jauzein, Vincent, Steyer, Jean-Philippe, Mairet, Francis, Bernard, Olivier, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de Recherche pour le Développement (IRD), Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), SAUR, International Water Association (IWA). INT., ProdInra, Migration, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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[SDV] Life Sciences [q-bio] ,[SDE] Environmental Sciences ,zooplancton ,microalgae ,[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences ,grazing ,process modelling ,wastewater - Abstract
International audience; Microalgae can be grown with wastewater in order to reduce the production cost, and recycle nitrogen and phosphorus from waste. Indeed, microalgal systems show great potential for extensive nutrient removal in wastewater treatment. High Rate Algal Ponds (HRAPs) however contain other organisms whose impact can be strong on the process dynamics. This work quantifies the role played by detritivores and algivores through a modelling approach. We present a model, in the framework of Activated Sludge Model, intended to describe the interaction between microalgae, zooplankton, and bacteria. The model is calibrated and tested with experimental data from a HARP fed with a WWTP. We show first that detritivores can have a positive role while they clarify the medium and provide light access to the algae stimulating micro-algae growth. The interaction microalgae/zoo-plankton is, however, much more complicated and grazing maintains a pressure on microalgae, and reduces the removal process efficiency.
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- 2017
33. Microbial Diversity and Cyanobacterial Production in Dziani Dzaha Crater Lake, a Unique Tropical Thalassohaline Environment
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Leboulanger, Christophe, Agogué, Hélène, Bernard, Cécile, Bouvy, Marc, Carré, Claire, Cellamare, Maria, Duval, Charlotte, Fouilland, Eric, Got, Patrice, Intertaglia, Laurent, Lavergne, Céline, Le Floc'h, Emilie, Roques, Cécile, Sarazin, Gérard, MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Molécules de Communication et Adaptation des Micro-Organismes (MCAM), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS)
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Chlorophyll ,[SDV]Life Sciences [q-bio] ,lcsh:Medicine ,Marine and Aquatic Sciences ,Biochemistry ,Comoros ,RNA, Ribosomal, 16S ,Cluster Analysis ,Biomass ,Photosynthesis ,lcsh:Science ,Islands ,Principal Component Analysis ,Geography ,Ecology ,Temperature ,Biodiversity ,Hydrogen-Ion Concentration ,Plants ,Plankton ,Nucleic acids ,Chemistry ,Ribosomal RNA ,Physical Sciences ,[SDE]Environmental Sciences ,Water Microbiology ,Research Article ,Freshwater Environments ,Chemical Elements ,Cell biology ,Cellular structures and organelles ,Ecological Metrics ,Algae ,Nitrogen ,Biomass (Ecology) ,Cyanobacteria ,Surface Water ,Sea Water ,Animals ,Non-coding RNA ,Models, Statistical ,Bacteria ,Chlorophyll A ,lcsh:R ,Ecology and Environmental Sciences ,Organisms ,Aquatic Environments ,Biology and Life Sciences ,Bodies of Water ,Invertebrates ,Carbon ,Oxygen ,Lakes ,Phytoplankton ,Earth Sciences ,RNA ,lcsh:Q ,Hydrology ,Ribosomes - Abstract
International audience; This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.6–14.5 g L-1 eq. CO32-, i.e. 160–220 mM compare to around 2–2.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 μg chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the photosynthetic biomass was dominated (>97% of total biovolume) by the filamentous cyanobacteria Arthrospira sp. with a straight morphotype. In situ daily photosynthetic oxygen production ranged from 17.3 to 22.2 g O2 m-2 d-1, consistent with experimental production / irradiance measurements and modeling. Heterotrophic bacterioplankton was extremely abundant, with cell densities up to 1.5 108 cells mL-1 in the whole water column. Isolation and culture of 59 Eubacteria strains revealed the prevalence of alkaliphilic and halophilic organisms together with taxa unknown to date, based on 16S rRNA gene analysis. A single cloning-sequencing approach using archaeal 16S rDNA gene primers unveiled the presence of diverse extremophilic Euryarchaeota. The water chemistry of Dziani Dzaha Lake supports the hypothesis that it was derived from seawater and strongly modified by geological conditions and microbial activities that increased the alkalinity. Dziani Dzaha has a unique consortium of cyanobacteria, phytoplankton, heterotrophic Eubacteria and Archaea, with very few unicellular protozoa, that will deserve further deep analysis to unravel its uncommon diversity. A single taxon, belonging to the genus Arthrospira, was found responsible for almost all photosynthetic primary production.
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- 2017
34. Étude des facteurs influençant la conservation des racines de betteraves sucrières, et des changements physiologiques au cours du stockage en lien avec la qualité industrielle
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Roques, Cécile, STAR, ABES, Institut Charles Viollette (ICV) - ULR 7394 (ICV), Université d'Artois (UA)-Université du Littoral Côte d'Opale (ULCO)-Institut Supérieur d'Agriculture-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université des Sciences et Technologie de Lille - Lille I, Patrice Halama, and Bertrand Vandoorne
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[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,Sucrose ,[SDV.SA] Life Sciences [q-bio]/Agricultural sciences ,Kestose - Abstract
Searching for innovative and favourable solutions in order to adapt to the abolition of production quotas, Tereos, an agricultural cooperative, leader of the French sugar market, is interested in the physiological changes which occur in the sugar beet roots during storage. The study of factors affecting the storability of roots, the analysis of physical and biochemical changes, and the identification of degradation indicators, are the main objectives of this thesis. This work was carried out in collaboration with the industrial direction. The link between the agronomical quality and the industrial quality is addressed for the first time in a joint project. Indeed, the physical and biochemical transformations suffered by roots during the conservation in piles induce the production of new molecules, and some of them are harmful for the sucrose extraction.With physical resistance tests and chromatographic analysis, some of the physiological changes of the roots are identified, and the sugar losses during storage are extended. Thanks to the introduction of new projects, as the study of volatile organic compounds and microbiological analysis, indicators of root degradation are suggested., Á la recherche de solutions innovantes et prometteuses pour I'adaptation à l'abolition des quotas de production, Tereos, coopérative agricole, leader du marché du sucre en France, s'intéresse aux changements physiologiques subis par les racines de betteraves sucrières au cours du stockage. L'étude des facteurs impactant le stockage des racines, I'analyse des modifications physiques et biochimiques, et l'identification d'indicateurs de dégradation ont fait I'objet de cette thèse. Ce travail a été mené en collaboration avec le service industriel. Le lien entre la qualité agronomique et la qualité industrielle des racines est pour la première fois abordé dans un projet commun. En effet, les transformations physiques et biochimiques subies par les racines pendant la conservation en silo induisent la production de nouvelles molécules, dont certaines sont nuisibles à l'extraction du saccharose. Par des tests de résistances physiques et des analyses chromatographiques, certains changements physiologiques des racines sont identifiés, et les pertes en sucre au cours du stockage sont approfondies. Grâce à I'introduction de projets nouveaux, tels que l'étude des composés organiques volatils et les analyses microbiologiques, des indicateurs de dégradation des racines sont suggérés.
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- 2017
35. Microbial successions during wastewater treatment start-up using microalgae
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Galès, Amandine, Lanouguere, Elodie, Bonnafous, Anaïs, Carré, Claire, Roques, Cécile, Leboulanger, Christophe, Caro, Audrey, Floc'h, Emilie, Poullain, Clothilde, Sialve, Bruno, Steyer, Jean-Philippe, Jauzein, Vincent, Fouilland, Eric, Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut de Recherche pour le Développement (IRD), SAUR, International Water Association (IWA). INT., and Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)
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[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2017
36. Oyster Farming, Temperature, and Plankton Influence the Dynamics of Pathogenic Vibrios in the Thau Lagoon
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Lopez-Joven, Carmen, primary, Rolland, Jean-Luc, additional, Haffner, Philippe, additional, Caro, Audrey, additional, Roques, Cécile, additional, Carré, Claire, additional, Travers, Marie-Agnès, additional, Abadie, Eric, additional, Laabir, Mohamed, additional, Bonnet, Delphine, additional, and Destoumieux-Garzón, Delphine, additional
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- 2018
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37. Control of the pH for marine microalgae polycultures: A key point for CO2fixation improvement in intensive cultures
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Galès, Amandine, Triplet, Sébastien, Geoffroy, Thibault, Roques, Cécile, Carré, Claire, Le Floc’h, Emilie, Lanfranchi, Mélissa, Simier, Monique, Roque d’Orbcastel, Emmanuelle, Przybyla, Cyrille, and Fouilland, Eric
- Abstract
•The highest conversion of CO2into carbon biomass was reached at pH 7.•The theoretical maximal biological conversion of CO2was estimated to be ca.60 %.•Lower and higher pH favoured respectively the amoebae and copepod development.•pH can be a tool for favouring one microalgal species among a natural assemblage.
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- 2020
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38. Chapitre III. Le couple dispositif/pratique dans les échanges interpersonnes
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Després-Lonnet, Marie, Gentes, Annie, Moreau, Émilie, and Roques, Cécile
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écriture numérique ,sociologie de la lecture ,Bibliothèque nationale de France ,Sociology ,pratique numérique ,internet ,Web ,SOC026000 ,JHB - Abstract
1. Une recherche spécifique dans un projet cohérent L’étude présentée dans ce chapitre a été structurée par deux types de choix que cette introduction vise à expliciter : elle porte sur un type de dispositif occupant une place particulière dans le processus de communication; elle part d’une approche de la technique remettant en cause l’approche habituelle des outils informatiques. Par le réseau et en réseau: forme écrite, dispositif technique et pratique de communication Au sein de la thémati...
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- 2013
39. Lire, écrire, récrire
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Babou, Igor, Béguin, Annette, Brochu, Danièle, Cotte, Dominique, Davallon, Jean, Després-Lonnet, Marie, Gentes, Annie, Jeanneret, Yves, Labelle, Sarah, Le Marec, Joëlle, Moreau, Émilie, Noël-Cadet, Nathalie, Perrier, Valérie, Quinton, Philippe, Roques, Cécile, Souchier, Emmanuël, Souchier, Emmanuël, Jeanneret, Yves, and Le Marec, Joëlle
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écriture numérique ,sociologie de la lecture ,Bibliothèque nationale de France ,Sociology ,pratique numérique ,internet ,Web ,SOC026000 ,JHB - Abstract
Quelles relations peut-il y avoir entre un ensemble de « sites Web » reliés à la Bibliothèque nationale de France, des messages électroniques échangés par un groupe d’étudiants, un corpus de « textes Web » sur les OGM (organismes génétiquement modifiés) ou bien encore les pratiques de travail dans une bibliothèque en cours de réaménagement ? Ces différents « terrains d’analyse » ont en commun d’être des lieux privilégiés pour observer la circulation des formes écrites dans la société et la façon dont cette circulation participe de la médiation sociale des savoirs. Issu d’une série de questionnements sur les transformations contemporaines du rapport à l’écrit, le projet de ce livre se fonde sur un ensemble de recherches individuelles et collectives menées depuis plusieurs années autour de « l’écrit d’écran », des « écrits de réseaux » et de l’analyse des usages des nouvelles technologies liées aux institutions culturelles. Recherches mues par le même souci de cerner et de comprendre les interrelations tissées entre le technique, le sémiotique et les usages des médias informatisés.
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- 2013
40. Pelagic population dynamics ofAureliasp. in French Mediterranean lagoons
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Marques, Raquel, primary, Albouy-Boyer, Séverine, additional, Delpy, Floriane, additional, Carré, Claire, additional, Le Floc'h, Émilie, additional, Roques, Cécile, additional, Molinero, Juan-Carlos, additional, and Bonnet, Delphine, additional
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- 2015
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41. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats
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De Wit, Rutger, primary, Gautret, Pascale, additional, Bettarel, Yvan, additional, Roques, Cécile, additional, Marlière, Christian, additional, Ramonda, Michel, additional, Nguyen Thanh, Thuy, additional, Tran Quang, Huy, additional, and Bouvier, Thierry, additional
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- 2015
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42. Significance of Plankton Community Structure and Nutrient Availability for the Control of Dinoflagellate Blooms by Parasites: A Modeling Approach
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Alves-de-Souza, Catharina, primary, Pecqueur, David, additional, Le Floc’h, Emilie, additional, Mas, Sébastien, additional, Roques, Cécile, additional, Mostajir, Behzad, additional, Vidussi, Franscesca, additional, Velo-Suárez, Lourdes, additional, Sourisseau, Marc, additional, Fouilland, Eric, additional, and Guillou, Laure, additional
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- 2015
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43. Contrasted responses of Ruditapes decussatus (filter and deposit feeding) and Loripes lacteus (symbiotic) exposed to polymetallic contamination (Port-Camargue, France)
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Caro, Audrey, primary, Chereau, Gaetan, additional, Briant, Nicolas, additional, Roques, Cécile, additional, Freydier, Rémi, additional, Delpoux, Sophie, additional, Escalas, Arthur, additional, and Elbaz-Poulichet, Françoise, additional
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- 2015
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44. Bacterial carbon dependence on freshly produced phytoplankton exudates under different nutrient availability and grazing pressure conditions in coastal marine waters
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Fouilland, Eric, primary, Tolosa, Imma, additional, Bonnet, Delphine, additional, Bouvier, Corinne, additional, Bouvier, Thierry, additional, Bouvy, Marc, additional, Got, Patrice, additional, Le Floc'h, Emilie, additional, Mostajir, Behzad, additional, Roques, Cécile, additional, Sempéré, Richard, additional, Sime-Ngando, Télesphore, additional, and Vidussi, Francesca, additional
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- 2013
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45. Phénomène d’Eaux Vertes à Picochlorum en lagune de Thau pendant les années 2018 et 2019. Observations environnementales
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Lagarde, Franck, Bec, Beatrice, Atteia Van Lis, Ariane, Gobet, Angelique, Richard, Marion, Derolez, Valerie, Mostajir, Behzad, Roques, Cécile, Foucault, Elodie, Messiaen, Gregory, Hubert, Clarisse, and Cimiterra, Nicolas
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Climate Change ,Cascade d’Effets ,Changement Climatique ,Anoxia ,Extreme Events ,Cascading Effects ,Changement de Communautés Phytoplanctoniques ,Picochlorum ,Marine Heatwave ,Lagune de Thau ,Anoxie ,2. Zero hunger ,Malaïgue ,Aphelidium-like ,Climate Variability ,Thau Lagoon ,Variabilité Climatique ,15. Life on land ,Green Water Phenomenon ,6. Clean water ,Evènements Extrêmes ,13. Climate action ,Canicule Marine ,Eaux Vertes ,Phytoplankton Community Change ,Réchauffement ,Warming - Abstract
After having been eutrophied until the 2000s, the Thau lagoon has been now on an ecological restoration trajectory according to the oligotrophisation process. However, 2018 appeared to be a turning point in its ecological functioning due to its disturbed hydroclimatic context with the appearance of an unprecedented phenomenon of green water significantly impacting the oyster farming sector in its productivity and socio-economy. Already described in the 1980s in the Leucate lagoon, this phenomenon had never been observed in Thau and the need to observe in order to understand led to the carrying out of environmental monitoring from January 2019 to January 2020 on 3 stations. The description of the spatio-temporal dynamics of phytoplankton and of the species causing green water was associated with the biogeochemistry of lagoon waters (nitrogen, phosphorus and silicate nutrients) and the dynamics of autotrophic and heterotrophic eukaryotic communities. This monitoring was completed by a diagnosis of macrophytes (including macroalgae and seagrass beds) carried out in 2019 in order to measure the impact of disturbances on this compartment. The hypothesis of a link between the remarkable hydroclimatic context of 2018 and this green water phenomenon was put forward. Our results showed that the hydroclimatic context of the Thau Basin has evolved with a trend towards an increase in annual average water temperatures (+1.6°C over 20 years between 2000 and 2019), with an increase in annual average salinities (+2 PSU between 2000 and 2019) and more intense periods of oversalinity (up to 110 days in 2012 and maximums of 42.9 in 2016). Winter storms, spring thunderstorms, summer heatwave, anoxy and autumn Mediterranean episodes of intense precipitation make 2018 an atypical year. This succession of extreme events resulted in the phenomenon of green water. This project helped to find the origin: a bloom of Picochlorum, a picophytoplankton known to be thermotolerant and halotolerant. Picochlorum dominated the phytoplankton from December 2018 to April 2019 followed by minor developments until August 2019. The return to more typical phytoplankton communities occurred in September 2019 until the end of monitoring in February 2020. This bloom could be linked to massive inputs of nitrogen and phosphate nutrients linked successively to heavy rainfall in spring, to the summer anoxy and to the autumn rainfall of the Mediterranean episodes. The population dynamics of Picochlorum was controlled by nutrients but probably also by a parasitoid predator of the Aphelidium type that was identified in a preliminary way. The precise identification of this parasitoid remains a prospect. The impacts of the malaigue and green water phenomena on the macrophytes have led to a decrease in the total macrophyte cover. The relative cover of reference species, such as eelgrass, has also decreased, with a greater impact on the western part of the basin. The extreme hydroclimatic events of 2018 induced a cascade of ecological effects with changes in phytoplankton communities. It took one year after the 2018 anoxy to return to the previous state, as in the case of the green waters of the Leucate lagoon in the 1980s. Mediterranean lagoon systems represent high-stakes areas with ecological, environmental, societal and economic issues. The ecological restoration of Mediterranean lagoons and the associated goods and services requires an understanding of the dynamics of the various physical, chemical, biological and societal compartments, in order to support the marine culture sectors and anticipate their future trajectories, particularly in a context of anthropisation and global change., Après avoir été eutrophisée jusque dans les années 2000, la lagune de Thau est depuis sur une trajectoire de restauration écologique selon le processus d’oligotrophisation. Cependant, l’année 2018 est apparue comme une année de bascule dans son fonctionnement écologique par son contexte hydroclimatique perturbé avec l’apparition d’un phénomène inédit d’eaux vertes impactant significativement la filière ostréicole dans sa productivité et sa socio-économie. Déjà décrit dans les années 1980 dans la lagune de Leucate, ce phénomène n’avait jamais été observé dans Thau et le besoin d’observer pour comprendre a abouti à la réalisation d’un suivi environnemental de janvier 2019 à janvier 2020 sur 3 stations. La description de la dynamique spatio-temporelle du phytoplancton et de l’espèce à l’origine d’eaux vertes a été associée à la biogéochimie des eaux lagunaires (nutriments azotés, phosphorés et silicatés) et à la dynamique des communautés eucaryotes autotrophes et hétérotrophes. Ce suivi a été complété par un diagnostic des macrophytes (incluant les macroalgues et les herbiers) réalisé en 2019 afin de mesurer l’impact des perturbations sur ce compartiment. L’hypothèse du lien entre le contexte hydroclimatique remarquable de l’année 2018 et ce phénomène d’eaux vertes a été posée. Nos résultats ont montré que le contexte hydroclimatique du bassin de Thau a évolué avec une tendance à l’augmentation des moyennes annuelles de températures de l’eau (+1.6°C sur 20 ans entre 2000 et 2019), avec l’augmentation des moyennes annuelles de salinités (+2 PSU entre 2000 et 2019) et des périodes de sursalinités plus intenses (jusqu’à 110 jours en 2012 et des maximums à 42,9 en 2016). Les tempêtes hivernales, les orages printaniers, la canicule estivale, la malaïgue et les épisodes méditerranéens automnaux de précipitations intenses font de l’année 2018, une année atypique. Cette succession d’évènements extrêmes a eu pour conséquence le phénomène d’eaux vertes. Ce projet a permis d’en trouver l’origine : une efflorescence de Picochlorum, picophytoplancton connu pour être thermotolérant et halotolérant. Picochlorum a dominé le phytoplancton de décembre 2018 à avril 2019 suivi de développements mineurs jusqu’en aout 2019. Le retour à des communautés phytoplanctoniques plus typiques s’est fait en septembre 2019 jusqu’à la fin du suivi en février 2020. Cette efflorescence a pu être reliée à des apports massifs en nutriments azotés et phosphatés liés successivement à des précipitations fortes au printemps, à la malaïgue estivale et aux précipitations automnales des épisodes méditerranéens. La dynamique de population du Picochlorum a été contrôlée par les nutriments mais probablement aussi par un prédateur parasitoïde de type Aphelidium identifié de façon préliminaire. L’identification précise de ce parasitoïde reste une perspective. Les impacts des phénomènes de malaïgue et d’eaux vertes sur les macrophytes ont induit une diminution du recouvrement total en macrophytes. Le recouvrement relatif en espèce de référence, comme les zostères, a également diminué avec un impact plus important sur la partie ouest du bassin. Les évènements extrêmes hydroclimatiques de 2018 ont induit une cascade d’effets écologiques avec changement de communautés phytoplanctoniques. Il aura fallu une année après la malaïgue de 2018 pour voir le retour à l’état antérieur, comme dans le cas des eaux vertes de la lagune de Leucate dans les années 1980. Les systèmes lagunaires méditerranéens représentent des zones à forts enjeux avec des problématiques écologiques, environnementales, sociétales et économiques. La restauration écologique des lagunes méditerranéennes et des biens et services associés nécessite de comprendre la dynamique des différents compartiments physiques, chimiques, biologiques et sociétaux, pour accompagner les filières des cultures marines et d’anticiper leurs trajectoires futures, en particulier dans un contexte d’anthropisation et de changement global.
46. Microbial Diversity and Cyanobacterial Production in Dziani Dzaha Crater Lake, a Unique Tropical Thalassohaline Environment.
- Author
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Leboulanger C, Agogué H, Bernard C, Bouvy M, Carré C, Cellamare M, Duval C, Fouilland E, Got P, Intertaglia L, Lavergne C, Le Floc'h E, Roques C, and Sarazin G
- Subjects
- Biomass, Carbon chemistry, Chlorophyll metabolism, Chlorophyll A, Cluster Analysis, Comoros, Geography, Hydrogen-Ion Concentration, Islands, Models, Statistical, Nitrogen chemistry, Oxygen analysis, Oxygen chemistry, Photosynthesis, Phytoplankton, Principal Component Analysis, RNA, Ribosomal, 16S metabolism, Temperature, Biodiversity, Cyanobacteria, Lakes microbiology, Water Microbiology
- Abstract
This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.6-14.5 g L-1 eq. CO32-, i.e. 160-220 mM compare to around 2-2.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 μg chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the photosynthetic biomass was dominated (>97% of total biovolume) by the filamentous cyanobacteria Arthrospira sp. with a straight morphotype. In situ daily photosynthetic oxygen production ranged from 17.3 to 22.2 g O2 m-2 d-1, consistent with experimental production / irradiance measurements and modeling. Heterotrophic bacterioplankton was extremely abundant, with cell densities up to 1.5 108 cells mL-1 in the whole water column. Isolation and culture of 59 Eubacteria strains revealed the prevalence of alkaliphilic and halophilic organisms together with taxa unknown to date, based on 16S rRNA gene analysis. A single cloning-sequencing approach using archaeal 16S rDNA gene primers unveiled the presence of diverse extremophilic Euryarchaeota. The water chemistry of Dziani Dzaha Lake supports the hypothesis that it was derived from seawater and strongly modified by geological conditions and microbial activities that increased the alkalinity. Dziani Dzaha has a unique consortium of cyanobacteria, phytoplankton, heterotrophic Eubacteria and Archaea, with very few unicellular protozoa, that will deserve further deep analysis to unravel its uncommon diversity. A single taxon, belonging to the genus Arthrospira, was found responsible for almost all photosynthetic primary production., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2017
- Full Text
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