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4 results on '"Hubert-Jean Ceccaldi"'

1. Heterotrophic prokaryote distribution along a 2300 km transect in the North Pacific subtropical gyre during a strong La Nina conditions: relationship between distribution and hydrological conditions

Author

Gérald Grégori, Hubert-Jean Ceccaldi, Hisayuki Arakawa, Mathias Girault, Aude Barani, Fuminori Hashihama, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institut méditerranéen d'océanologie ( MIO ), and Centre National de la Recherche Scientifique ( CNRS ) -Université de Toulon ( UTLN ) -Aix Marseille Université ( AMU ) -Institut de Recherche pour le Développement ( IRD )

Subjects
[ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, lcsh:QE1-996.5, lcsh:Life, Biology, Spatial distribution, Salinity, lcsh:Geology, La Niña, lcsh:QH501-531, Oceanography, Eddy, 13. Climate action, Ocean gyre, Anticyclone, lcsh:QH540-549.5, Seawater, 14. Life underwater, lcsh:Ecology, Transect, Ecology, Evolution, Behavior and Systematics, Earth-Surface Processes
Abstract

The spatial distribution of heterotrophic prokaryotes was investigated during the Tokyo–Palau cruise in the western part of the North Pacific subtropical gyre (NPSG) along a north–south transect between 33.60 and 13.25° N. The cruise was conducted in three different hydrological areas identified as the Kuroshio region, the subtropical gyre area and the transition zone. Two eddies were crossed along the transect: one cold-core cyclonic eddy and one warm-core anticyclonic eddy and distributions of the heterotrophic prokaryotes were recorded. By using analytical flow cytometry and a nucleic acid staining protocol, heterotrophic prokaryotes were discriminated into three subgroups depending on their nucleic acid content (low, high and very high nucleic acid contents labelled LNA, HNA and VHNA, respectively). Statistical analyses performed on the data set showed that LNA, mainly associated with low temperature and low salinity, were dominant in all the hydrological regions. In contrast, HNA distribution seemed to be associated with temperature, salinity, Chl a and silicic acid. A latitudinal increase in the HNA / LNA ratio was observed along the north–south transect and was related to higher phosphate and nitrate concentrations. However, the opposite relationship observed for the VHNA / HNA ratio suggested that the link between nucleic acid content and oligotrophic conditions is not linear, underlying the complexity of the biodiversity in the VHNA, HNA and LNA subgroups. In the Kuroshio Current, it is suggested that the high concentration of heterotrophic prokaryotes observed at station 4 was linked to the path of the cold cyclonic eddy core. In contrast, it is thought that low concentrations of heterotrophic prokaryotes in the warm core of the anticyclonic gyre (Sta. 9) are related to the low nutrient concentrations measured in the seawater column. Our results showed that the high variability between the various heterotrophic prokaryote cluster abundances depend both on the mesoscale structures and the oligotrophic gradient.

Published
2015
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2. Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Nina condition: relationship with the hydrological conditions

Author

Fuminori Hashihama, Gérald Grégori, Mathias Girault, Hubert-Jean Ceccaldi, Aude Barani, Shinko Kinouchi, Hisayuki Arakawa, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie ( MIO ), and Centre National de la Recherche Scientifique ( CNRS ) -Université de Toulon ( UTLN ) -Aix Marseille Université ( AMU ) -Institut de Recherche pour le Développement ( IRD )

Subjects
0106 biological sciences, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, Water mass, 010504 meteorology & atmospheric sciences, lcsh:Life, 01 natural sciences, Water column, Ocean gyre, lcsh:QH540-549.5, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, biology, 010604 marine biology & hydrobiology, lcsh:QE1-996.5, Front (oceanography), biology.organism_classification, lcsh:Geology, La Niña, lcsh:QH501-531, Oceanography, Eddy, 13. Climate action, Anticyclone, Prochlorococcus, lcsh:Ecology, Geology
Abstract

The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG) during La Niña, a cold phase of El Niño Southern Oscillation (ENSO). Observations were conducted in a north-south transect (33.6–13.25° N) along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like) defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC) at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature) and La Niña (this study) conditions seems to demonstrate that La Niña conditions lead to higher concentrations of Synechococcus in the Subtropical gyre and a lower abundance of Synechococcus in the Kuroshio region. Our results suggest that the west part of NPSG is a complex area, where different water masses, salinity fronts and eddies lead to a heterogeneous distribution of ultraphytoplankton assemblages in the upper layer of the water column.

Published
2013
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3. The Management of Mediterranean Coastal Habitats: A Plea for a Socio-ecosystem-Based Approach

Author

Mireille Harmelin-Vivien, Daniel Faget, Thierry Thibaut, Thomas Changeux, Jean Blanchot, Richard Sempéré, Sandrine Ruitton, Vanina Pasqualini, Charles-François Boudouresque, Marc Pagano, Adrien Goujard, Aurelie Blanfuné, Francois Carlotti, Daniela Bănaru, Michèle Perret-Boudouresque, Elodie Rouanet, Delphine Thibault, Patrick Astruch, Laurence Le Direach, Diversité, évolution et écologie fonctionnelle marine (DIMAR), Centre National de la Recherche Scientifique (CNRS)-Université de la Méditerranée - Aix-Marseille 2, Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), UR CYROCO (IRD/ARVAM), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), GIS Posidonie, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Ecologie Marine et BIOdiversité (EMBIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Physique et Biologique (LOPB), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Temps, espaces, langages Europe méridionale-Méditerranée (TELEMME), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [Réunion]), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), ICEMASA, University of Cape Town, Université Nice Sophia Antipolis (1965 - 2019) (UNS), Hubert-Jean Ceccaldi, Yves Hénocque, Teruhisa Komatsu, Patrick Prouzet, Benoit Sautour, and Jiro Yoshida

Subjects
0106 biological sciences, [SDV]Life Sciences [q-bio], Biodiversity, Mediterranean, 010603 evolutionary biology, 01 natural sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Marine ecosystem, Ecosystem, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, biodiversity, Abiotic component, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Ecology, 010604 marine biology & hydrobiology, Pelagic zone, 15. Life on land, environmentalist lobbies, [SDE.ES]Environmental Sciences/Environmental and Society, Habitat, 13. Climate action, Benthic zone, [SDE]Environmental Sciences, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, socio-ecosystem, management, Global biodiversity
Abstract

International audience; Biodiversity is often defined erroneously as the number of species. The higher the number of species, the better the status or the health of a habitat is considered to be. Managers, stakeholders and environmentalists worldwide often prioritize the ‘species approach’. The protection of an iconic and endearing species is obviously easier than that of tiny zooplankton species, although the latter may play a far more important role than the former in the functioning of healthy ecosystems. The species approach has been widely favoured compared to the ecosystem approach. However, ‘species-by-species’ management is unrealistic. The problem is that the management of natural habitats is often driven by environmentalist lobbies on the basis of taxonomy (e.g. mammals, turtles, birds, iconic fish, flowering plants, etc.) and disciplinary lobbies (biology, benthos, pelagos, contaminants, currents, etc.). Ecosystems are units of biological and spatial organization that include all the organisms, their interactions, the functional compartments they belong to, along with the components of the abiotic environment. The concept of the socio-ecosystem is useful insofar as it emphasizes the fact that man is part of ecosystems. Here, the authors make use of four case studies, in the Mediterranean Sea, in an attempt to demonstrate the interest of a comprehensive, socio-ecosystem-based approach in the field of environmental management. They also highlight the importance of tackling the coupling between benthic and pelagic ecosystems and between terrestrial and marine ecosystems.

Published
2020
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4. From data to End-to -End Models:15 years of research to describe the dynamics of exploited marine ecosystems in the Eastern Channel

Author

Martin Huret, Sandrine Vaz, Olivier Le Pape, Stéphanie Mahévas, Loïc Gasche, Morgane Travers-Trolet, Raphael Girardin, Paul Marchal, Laboratoire Ressources halieutiques Manche Mer du nord, IFREMER Centre Manche Mer du Nord, (HMMN), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Écologie et Modèles pour l'halieutique (EMH), Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Unité de recherche Sciences et Technologies Halieutiques (STH), UMR 212 EME 'écosystèmes marins exploités' (EME), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM), Hubert-Jean Ceccaldi, Yves Hénocque, Yasuyuki Koike, Teruhisa Komatsu, Georges Stora, Marie-Hélène Tusseau-Vuillemin, Écologie et Modèles pour l'Halieutique (IFREMER EMH), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), 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), Laboratoire Ressources halieutiques Boulogne sur mer (LRHBL), Halieutique Manche Mer du Nord (HMMN), Écologie et Modèles pour l'Halieutique (EMH), and Sciences et Technologies Halieutiques (STH)

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, Ecosystem modelling, Flatfish, 01 natural sciences, Eastern English Channel, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, End-to-end principle, Ecosystem, Marine ecosystem, 14. Life underwater, Sound (geography), 0105 earth and related environmental sciences, Abiotic component, geography, geography.geographical_feature_category, Spatial analyses, business.industry, Ecology, 010604 marine biology & hydrobiology, Environmental resource management, [SDV.SA.STP]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of fishery, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, business, Communication channel
Abstract

Proceedings of the 15th French-Japanese Oceanography Symposium; International audience; Considerable research has been conducted in the past 15 years around the Eastern English Channel ecosystem. Data collected since the 1970s on the biotic and abiotic compartments have been collated and mapped out in the mid-2000. This spatially explicit information formed a sound basis to improve knowledge on, and model, the functioning and dynamics of key ecosystem compartments, with a focus on flatfish species and fisheries and their interactions with other sectors of activity (aggregate extractions, maritime traffic). The more recent ongoing works are dedicated to the integration of those processes into several complementary end-to-end ecosystem models.

Published
2015
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