Author: "Mireille Pujo-Pay" - Searchworks@Jio Institute Digital Library Search Results

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1. Open science resources from the Tara Pacific expedition across coral reef and surface ocean ecosystems

Author: Fabien Lombard, Guillaume Bourdin, Stéphane Pesant, Sylvain Agostini, Alberto Baudena, Emilie Boissin, Nicolas Cassar, Megan Clampitt, Pascal Conan, Ophélie Da Silva, Céline Dimier, Eric Douville, Amanda Elineau, Jonathan Fin, J. Michel Flores, Jean-François Ghiglione, Benjamin C. C. Hume, Laetitia Jalabert, Seth G. John, Rachel L. Kelly, Ilan Koren, Yajuan Lin, Dominique Marie, Ryan McMinds, Zoé Mériguet, Nicolas Metzl, David A. Paz-García, Maria Luiza Pedrotti, Julie Poulain, Mireille Pujo-Pay, Joséphine Ras, Gilles Reverdin, Sarah Romac, Alice Rouan, Eric Röttinger, Assaf Vardi, Christian R. Voolstra, Clémentine Moulin, Guillaume Iwankow, Bernard Banaigs, Chris Bowler, Colomban de Vargas, Didier Forcioli, Paola Furla, Pierre E. Galand, Eric Gilson, Stéphanie Reynaud, Shinichi Sunagawa, Matthew B. Sullivan, Olivier P. Thomas, Romain Troublé, Rebecca Vega Thurber, Patrick Wincker, Didier Zoccola, Denis Allemand, Serge Planes, Emmanuel Boss, and Gaby Gorsky
Subjects: Science
Abstract: Abstract The Tara Pacific expedition (2016–2018) sampled coral ecosystems around 32 islands in the Pacific Ocean and the ocean surface waters at 249 locations, resulting in the collection of nearly 58 000 samples. The expedition was designed to systematically study warm-water coral reefs and included the collection of corals, fish, plankton, and seawater samples for advanced biogeochemical, molecular, and imaging analysis. Here we provide a complete description of the sampling methodology, and we explain how to explore and access the different datasets generated by the expedition. Environmental context data were obtained from taxonomic registries, gazetteers, almanacs, climatologies, operational biogeochemical models, and satellite observations. The quality of the different environmental measures has been validated not only by various quality control steps, but also through a global analysis allowing the comparison with known environmental large-scale structures. Such publicly released datasets open the perspective to address a wide range of scientific questions.
Published: 2023
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2. Development of a Frugal, In Situ Sensor Implementing a Ratiometric Method for Continuous Monitoring of Turbidity in Natural Waters

Author: Raul Sanchez, Michel Groc, Renaud Vuillemin, Mireille Pujo-Pay, and Vincent Raimbault
Subjects: turbidity, frugal sensors, ratiometric, in situ, water quality, Chemical technology, TP1-1185
Abstract: Turbidity is a commonly used indicator of water quality in continental and marine waters and is mostly caused by suspended and colloidal particles such as organic and inorganic particles. Many methods are available for the measurement of turbidity, ranging from the Secchi disk to infrared light-based benchtop or in situ turbidimeters as well as acoustic methods. The operational methodologies of the large majority of turbidity instruments involve the physics of light scattering and absorption by suspended particles when light is passed through a sample. As such, in the case of in situ monitoring in water bodies, the measurement of turbidity is highly influenced by external light and biofouling. Our motivation for this project is to propose an open-source, low-cost in situ turbidity sensor with a suitable sensitivity and operating range to operate in low-to-medium-turbidity natural waters. This prototype device combines two angular photodetectors and two infrared light sources with different positions, resulting in two different types of light detection, namely nephelometric (i.e., scattering) and attenuation light, according to the ISO 7027 method. The mechanical design involves 3D-printed parts by stereolithography, which are compatible with commercially available waterproof enclosures, thus ensuring easy integration for future users. An effort was made to rely on mostly off-the-shelf electronic components to encourage replication of the system, with the use of a highly integrated photometric front-end commonly used in portable photoplethysmography systems. The sensor was tested in laboratory conditions against a commercial benchtop turbidimeter with Formazin standards. The monitoring results were analyzed, obtaining a linear trendline from 0 to 50 Nephelometric Turbidity Unit (NTU) and an accuracy of +/−0.4 NTU in the 0 to 10 NTU range with a response time of less than 100 ms.
Published: 2023
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3. Microbial Diversity and Activity During the Biodegradation in Seawater of Various Substitutes to Conventional Plastic Cotton Swab Sticks

Author: Justine Jacquin, Nolwenn Callac, Jingguang Cheng, Carolane Giraud, Yonko Gorand, Clement Denoual, Mireille Pujo-Pay, Pascal Conan, Anne-Leila Meistertzheim, Valerie Barbe, Stéphane Bruzaud, and Jean-François Ghiglione
Subjects: plastisphere, biofouling, plastic biodegradation, single-used plastics, microbial colonization, Microbiology, QR1-502
Abstract: The European Parliament recently approved a new law banning single-use plastic items for 2021 such as plastic plates, cutlery, straws, cotton swabs, and balloon sticks. Transition to a bioeconomy involves the substitution of these banned products with biodegradable materials. Several materials such as polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), poly(butylene succinate) (PBS), polyhydroxybutyrate-valerate (PHBV), Bioplast, and Mater-Bi could be good candidates to substitute cotton swabs, but their biodegradability needs to be tested under marine conditions. In this study, we described the microbial life growing on these materials, and we evaluated their biodegradability in seawater, compared with controls made of non-biodegradable polypropylene (PP) or biodegradable cellulose. During the first 40 days in seawater, we detected clear changes in bacterial diversity (Illumina sequencing of 16S rRNA gene) and heterotrophic activity (incorporation of 3H-leucine) that coincided with the classic succession of initial colonization, growth, and maturation phases of a biofilm. Biodegradability of the cotton swab sticks was then tested during another 94 days under strict diet conditions with the different plastics as sole carbon source. The drastic decrease of the bacterial activity on PP, PLA, and PBS suggested no bacterial attack of these materials, whereas the bacterial activity in PBAT, Bioplast, Mater-Bi, and PHBV presented similar responses to the cellulose positive control. Interestingly, the different bacterial diversity trends observed for biodegradable vs. non-biodegradable plastics allowed to describe potential new candidates involved in the degradation of these materials under marine conditions. This better understanding of the bacterial diversity and activity dynamics during the colonization and biodegradation processes contributes to an expanding baseline to understand plastic biodegradation in marine conditions and provide a foundation for further decisions on the replacement of the banned single-used plastics.
Published: 2021
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4. Seasonal and Interannual Variability of the CO2 System in the Eastern Mediterranean Sea: A Case Study in the North Western Levantine Basin

Author: Cathy Wimart-Rousseau, Thibaut Wagener, Marta Álvarez, Thierry Moutin, Marine Fourrier, Laurent Coppola, Laure Niclas-Chirurgien, Patrick Raimbault, Fabrizio D’Ortenzio, Xavier Durrieu de Madron, Vincent Taillandier, Franck Dumas, Pascal Conan, Mireille Pujo-Pay, and Dominique Lefèvre
Subjects: carbonate system, Mediterranean Sea, acidification, CO2 fluxes, Levantine Sea, inorganic carbon, Science, General. Including nature conservation, geographical distribution, QH1-199.5
Abstract: The seasonal variability of the carbonate system in the eastern Mediterranean Sea (EMed) was investigated based on discrete total alkalinity (AT), total dissolved inorganic carbon (CT), and pH measurements collected during three cruises around Crete between June 2018 and March 2019. This study presents a detailed description of this new carbonate chemistry dataset in the eastern Mediterranean Sea. We show that the North Western Levantine Basin (NWLB) is unique in terms of range of AT variation vs. CT variation in the upper water column over an annual cycle. The reasons for this singularity of the NWLB can be explained by the interplay between strong evaporation and the concomitant consumption of CT by autotrophic processes. The high range of AT variations, combined to temperature changes, has a strong impact on the variability of the seawater pCO2 (pCO2SW). Based on Argo float data, an entire annual cycle for pCO2SW in the NWLB has been reconstructed in order to estimate the temporal sequence of the potential “source” and “sink” of atmospheric CO2. By combining this dataset with previous observations in the NWLB, this study shows a significant ocean acidification and a decrease in the oceanic surface pHT25 of −0.0024 ± 0.0004 pHT25 units.a–1. The changes in the carbonate system are driven by the increase of atmospheric CO2 but also by unexplained temporal changes in the surface AT content. If we consider that the EMed will, in the future, encounter longer, more intense and warmer summer seasons, this study proposes some perspectives on the carbonate system functioning of the “future” EMed.
Published: 2021
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5. Relative Influence of Plastic Debris Size and Shape, Chemical Composition and Phytoplankton-Bacteria Interactions in Driving Seawater Plastisphere Abundance, Diversity and Activity

Author: Jingguang Cheng, Justine Jacquin, Pascal Conan, Mireille Pujo-Pay, Valérie Barbe, Matthieu George, Pascale Fabre, Stéphane Bruzaud, Alexandra Ter Halle, Anne-Leila Meistertzheim, and Jean-François Ghiglione
Subjects: plastic litter, plastisphere, biofilm, biofouling, colonization, microbial ecotoxicology, Microbiology, QR1-502
Abstract: The thin film of life that inhabits all plastics in the oceans, so-called “plastisphere,” has multiple effects on the fate and impacts of plastic in the marine environment. Here, we aimed to evaluate the relative influence of the plastic size, shape, chemical composition, and environmental changes such as a phytoplankton bloom in shaping the plastisphere abundance, diversity and activity. Polyethylene (PE) and polylactide acid (PLA) together with glass controls in the forms of meso-debris (18 mm diameter) and large-microplastics (LMP; 3 mm diameter), as well as small-microplastics (SMP) of 100 μm diameter with spherical or irregular shapes were immerged in seawater during 2 months. Results of bacterial abundance (confocal microscopy) and diversity (16S rRNA Illumina sequencing) indicated that the three classical biofilm colonization phases (primo-colonization after 3 days; growing phase after 10 days; maturation phase after 30 days) were not influenced by the size and the shape of the materials, even when a diatom bloom (Pseudo-nitzschia sp.) occurred after the first month of incubation. However, plastic size and shape had an effect on bacterial activity (3H leucine incorporation). Bacterial communities associated with the material of 100 μm size fraction showed the highest activity compared to all other material sizes. A mature biofilm developed within 30 days on all material types, with higher bacterial abundance on the plastics compared to glass, and distinct bacterial assemblages were detected on each material type. The diatom bloom event had a great impact on the plastisphere of all materials, resulting in a drastic change in diversity and activity. Our results showed that the plastic size and shape had relatively low influence on the plastisphere abundance, diversity, and activity, as compared to the plastic composition or the presence of a phytoplankton bloom.
Published: 2021
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6. Nutrient Fluxes Associated With Submarine Groundwater Discharge From Karstic Coastal Aquifers (Côte Bleue, French Mediterranean Coastline)

Author: Simon Bejannin, Joseph James Tamborski, Pieter van Beek, Marc Souhaut, Thomas Stieglitz, Olivier Radakovitch, Christelle Claude, Pascal Conan, Mireille Pujo-Pay, Olivier Crispi, Emilie Le Roy, and Claude Estournel
Subjects: submarine groundwater discharge, Mediterranean sea, radium isotopes, thermal infrared remote sensing, nutrient fluxes, GEOTRACES, Environmental sciences, GE1-350
Abstract: Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the nearshore permeable sediments and coastal aquifer. Field work was conducted at different periods of the year to study the temporal variability of the chemical fluxes. Offshore transects of 223Ra and 224Ra were used to derive horizontal eddy diffusivity coefficients that were subsequently combined with surface water nutrient gradients (NO2− + NO3−, DSi) to determine the net nutrient fluxes from SGD. The estimated DSi and (NO2− + NO3−) fluxes are 6.2 ± 5.0 *103 and 4.0 ± 2.0 *103 mol d−1 per km of coastline, respectively. We attempted to further constrain these SGD fluxes by combining horizontal eddy diffusivity and 228Ra gradients. However, SGD endmember selection in this area (terrestrial groundwater discharge vs. porewater) adds further uncertainty to the flux calculation and thus prevented us from calculating a reliable flux using this latter method. Additionally, the relatively long half-life of 228Ra (5.75 y) makes it sensitive to specific circulation patterns in this coastal region, including sporadic intrusions of Rhône river waters that impact both the 228Ra and nutrient surface water distributions. We show that SGD nutrient fluxes locally reach up to 20 times the nutrient fluxes from a small river (Huveaune River). On a regional scale, DSi fluxes driven by SGD vary between 0.1 and 1.4% of the DSi inputs of the Rhône River, while the (NO2− + NO3−) fluxes driven by SGD on this 22 km long coastline are between 0.1 and 0.3% of the Rhône River inputs, the largest river that discharges into the Mediterranean Sea. Interestingly, the nutrient fluxes reported here are similar in magnitude compared with the fluxes quantified along the sandy beach of La Franqui, in the western Gulf of Lions (Tamborski et al., 2018), despite the different lithology of the two areas (karst systems vs. unconsolidated sediment).
Published: 2020
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7. Expanding Tara Oceans Protocols for Underway, Ecosystemic Sampling of the Ocean-Atmosphere Interface During Tara Pacific Expedition (2016–2018)

Author: Gabriel Gorsky, Guillaume Bourdin, Fabien Lombard, Maria Luiza Pedrotti, Samuel Audrain, Nicolas Bin, Emmanuel Boss, Chris Bowler, Nicolas Cassar, Loic Caudan, Genevieve Chabot, Natalie R. Cohen, Daniel Cron, Colomban De Vargas, John R. Dolan, Eric Douville, Amanda Elineau, J. Michel Flores, Jean Francois Ghiglione, Nils Haëntjens, Martin Hertau, Seth G. John, Rachel L. Kelly, Ilan Koren, Yajuan Lin, Dominique Marie, Clémentine Moulin, Yohann Moucherie, Stéphane Pesant, Marc Picheral, Julie Poulain, Mireille Pujo-Pay, Gilles Reverdin, Sarah Romac, Mathew B. Sullivan, Miri Trainic, Marc Tressol, Romain Troublé, Assaf Vardi, Christian R. Voolstra, Patrick Wincker, Sylvain Agostini, Bernard Banaigs, Emilie Boissin, Didier Forcioli, Paola Furla, Pierre E. Galand, Eric Gilson, Stéphanie Reynaud, Shinichi Sunagawa, Olivier P. Thomas, Rebecca Lisette Vega Thurber, Didier Zoccola, Serge Planes, Denis Allemand, and Eric Karsenti
Subjects: neuston/plankton genomics/taxonomy/imaging, aerosols, NCP, IOP, trace metals, microplastic, Science, General. Including nature conservation, geographical distribution, QH1-199.5
Abstract: Interactions between the ocean and the atmosphere occur at the air-sea interface through the transfer of momentum, heat, gases and particulate matter, and through the impact of the upper-ocean biology on the composition and radiative properties of this boundary layer. The Tara Pacific expedition, launched in May 2016 aboard the schooner Tara, was a 29-month exploration with the dual goals to study the ecology of reef ecosystems along ecological gradients in the Pacific Ocean and to assess inter-island and open ocean surface plankton and neuston community structures. In addition, key atmospheric properties were measured to study links between the two boundary layer properties. A major challenge for the open ocean sampling was the lack of ship-time available for work at “stations”. The time constraint led us to develop new underway sampling approaches to optimize physical, chemical, optical, and genomic methods to capture the entire community structure of the surface layers, from viruses to metazoans in their oceanographic and atmospheric physicochemical context. An international scientific consortium was put together to analyze the samples, generate data, and develop datasets in coherence with the existing Tara Oceans database. Beyond adapting the extensive Tara Oceans sampling protocols for high-resolution underway sampling, the key novelties compared to Tara Oceans’ global assessment of plankton include the measurement of (i) surface plankton and neuston biogeography and functional diversity; (ii) bioactive trace metals distribution at the ocean surface and metal-dependent ecosystem structures; (iii) marine aerosols, including biological entities; (iv) geography, nature and colonization of microplastic; and (v) high-resolution underway assessment of net community production via equilibrator inlet mass spectrometry. We are committed to share the data collected during this expedition, making it an important resource important resource to address a variety of scientific questions.
Published: 2019
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8. Nanoplanktonic diatoms are globally overlooked but play a role in spring blooms and carbon export

Author: Karine Leblanc, Bernard Quéguiner, Frédéric Diaz, Véronique Cornet, Mónica Michel-Rodriguez, Xavier Durrieu de Madron, Chris Bowler, Shruti Malviya, Melilotus Thyssen, Gérald Grégori, Mathieu Rembauville, Olivier Grosso, Julie Poulain, Colomban de Vargas, Mireille Pujo-Pay, and Pascal Conan
Subjects: Science
Abstract: Diatoms are major oceanic primary producers, but some species belonging to the nano- and even picoplankton size are poorly characterized. Here the authors describe a massive spring bloom of the smallest known diatom in the Mediterranean Sea and reveal their general oversight at the global scale.
Published: 2018
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9. Aerosol inputs affect the optical signatures of dissolved organic matter in NW Mediterranean coastal waters

Author: E. Denisse Sánchez-Pérez, Isabel Marín, Sdena Nunes, Fran L. Aparicio, Laura Fernández-González, Francesc Peters, Mireille Pujo-Pay, Pascal Conan, and Cèlia Marrasé
Subjects: fdom, aerosol deposition, doc, mediterranean sea, Aquaculture. Fisheries. Angling, SH1-691
Abstract: Aeolian inputs of organic and inorganic nutrients to the ocean are important as they can enhance biological production in surface waters, especially in oligotrophic areas like the Mediterranean. The Mediterranean littoral is particularly exposed to both anthropogenic and Saharan aerosol depositions on a more or less regular basis. During the last few decades experimental studies have been devoted to examining the effect of inorganic nutrient inputs from dust on microbial activity. In this study, we performed experiments at two different locations of the NW Mediterranean, where we evaluated the changes in the quality and quantity of dissolved organic matter due to atmospheric inputs of different origin (Saharan and anthropogenic) and its subsequent transformations mediated by microbial activities. In both experiments the humic-like and protein-like substances, and the fluorescence quantum yield increased after addition. In general, these changes in the quality of dissolved organic matter did not significantly affect the prokaryotes. The recalcitrant character of the fluorescent dissolved organic matter (FDOM) associated with aerosols was confirmed, as we found negligible utilization of chromophoric compounds over the experimental period. We framed these experiments within a two-year time series data set of atmospheric deposition and coastal surface water analyses. These observations showed that both Saharan and anthropogenic inputs induced changes in the quality of organic matter, increasing the proportion of FDOM substances. This increase was larger during Saharan dust events than in the absence of Saharan influence.
Published: 2016
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10. Microbial Ecotoxicology of Marine Plastic Debris: A Review on Colonization and Biodegradation by the 'Plastisphere'

Author: Justine Jacquin, Jingguang Cheng, Charlène Odobel, Caroline Pandin, Pascal Conan, Mireille Pujo-Pay, Valérie Barbe, Anne-Leila Meistertzheim, and Jean-François Ghiglione
Subjects: bacteria, marine plastics debris, colonization, biodegradation, metabolic pathways, Microbiology, QR1-502
Abstract: Over the last decades, it has become clear that plastic pollution presents a global societal and environmental challenge given its increasing presence in the oceans. A growing literature has focused on the microbial life growing on the surfaces of these pollutants called the “plastisphere,” but the general concepts of microbial ecotoxicology have only rarely been integrated. Microbial ecotoxicology deals with (i) the impact of pollutants on microbial communities and inversely (ii) how much microbes can influence their biodegradation. The goal of this review is to enlighten the growing literature of the last 15 years on microbial ecotoxicology related to plastic pollution in the oceans. First, we focus on the impact of plastic on marine microbial life and on the various functions it ensures in the ecosystems. In this part, we also discuss the driving factors influencing biofilm development on plastic surfaces and the potential role of plastic debris as vector for dispersal of harmful pathogen species. Second, we give a critical view of the extent to which marine microorganisms can participate in the decomposition of plastic in the oceans and of the relevance of current standard tests for plastic biodegradability at sea. We highlight some examples of metabolic pathways of polymer biodegradation. We conclude with several questions regarding gaps in current knowledge of plastic biodegradation by marine microorganisms and the identification of possible directions for future research.
Published: 2019
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11. Marine Biodegradation of Tailor-Made Polyhydroxyalkanoates (Pha) Influenced by the Chemical Structure and Associated Bacterial Communities

Author: Ghiglione, Jean-François, primary, Philip, Léna, additional, lemechko, pierre, additional, EYHERAGUIBEL, Boris, additional, Meistertzheim, Anne-Leila, additional, Mireille, Pujo-Pay, additional, conan, pascal, additional, Barbe, Valérie, additional, Bruzaud, Stéphane, additional, and Derippe, Gabrielle, additional
Published: 2023
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12. Evidence of coupled autotrophy and heterotrophy on plastic biofilms and its influence on surrounding seawater

Author: Pascal Conan, Léna Philip, Eva Ortega-Retuerta, Charlène Odobel, Clélia Duran, Caroline Pandin, Carolane Giraud, Anne-Leila Meistertzheim, Valérie Barbe, Alexandra Ter Hall, Mireille Pujo-Pay, Jean-François Ghiglione, Université Paris Cité (UPCité), Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC), Institut de sciences exactes et appliquées (ISEA), Université de la Nouvelle-Calédonie (UNC), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), SMODD - Systèmes Moléculaires Organisés et Développement Durable (SMODD), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT)
Subjects: History, Autotrophic Processes, Polymers and Plastics, Bacteria, Health, Toxicology and Mutagenesis, Microplastics, Heterotrophic Processes, General Medicine, Toxicology, Pollution, Industrial and Manufacturing Engineering, Carbon, Polyethylene, Biofilms, [CHIM]Chemical Sciences, Seawater, Business and International Management, Plastics
Abstract: We measured phytoplankton primary production and heterotrophic bacterial activities on microplastics and seawater in the Northwestern Mediterranean Sea during two 3-month spring periods over 2 consecutive years. Microorganisms growing on a 5 mm diameter low density polyethylene films (LDPE; 200 μm thick) faced two contrasting conditions depending on the year. Spring 2018 was characterized by consistent nutrient inputs and bloom development. In spring 2019, nutrient inputs and bloom were low. For the first time, we observed a clear coupling between primary production and heterotrophic prokaryote production on microplastics during both years, but with different intensity between years that reflected the crucial role of the trophic environmental conditions (nutrient supply) in shaping microbial activities on plastics. We found that high primary production on plastics could support the whole (net autotrophy) or the majority of the bacterial carbon demand needed for heterotrophic activities, supplemented by other carbon sources if surrounding waters are highly productive. We propose that microbial activity on plastics influences the microbial community in the surrounding seawater, especially when the environmental conditions are less favorable. An illustrative image of the role of plastics in the environment could be that of an inverter in an electrical circuit that mitigates both positive and negative variations. Our results highlight the potential role of the plastisphere in shaping biogeochemical cycles in the context of increasing amounts of plastic particles in the marine environment.
Published: 2022

13. Supplementary material to 'Seasonal and interannual variability of the pelagic ecosystem and of the organic carbon budget in the Rhodes Gyre (Eastern Mediterranean): influence of winter mixing'

Author: Joelle Habib, Caroline Ulses, Claude Estournel, Milad Fakhri, Patrick Marsaleix, Mireille Pujo-Pay, Pascal Conan, Marine Fourrier, Laurent Coppola, Alexandre Mignot, and Laurent Mortier
Published: 2022

14. Seasonal and interannual variability of the pelagic ecosystem and of the organic carbon budget in the Rhodes Gyre (Eastern Mediterranean): influence of winter mixing

Author: Joelle Habib, Caroline Ulses, Claude Estournel, Milad Fakhri, Patrick Marsaleix, Mireille Pujo-Pay, Pascal Conan, Marine Fourrier, Laurent Coppola, Alexandre Mignot, Laurent Mortier, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Council for Scientific Research = Conseil national de la recherche scientifique du Liban [Lebanon] (CNRS-L), Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), OSU Stations marines (STAMAR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Mercator Ocean International [Toulouse], Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: [SDV]Life Sciences [q-bio]
Abstract: The Rhodes Gyre is a cyclonic persistent feature of the general circulation of the Levantine Basin in the eastern Mediterranean Sea. Although it is located in the most oligotrophic basin of the Mediterranean Sea, it is a relatively high primary production area due to strong winter nutrient supply associated with the formation of Levantine Intermediate Water. In this study, a 3D coupled hydrodynamic-biogeochemical model (SYMPHONIE/Eco3M-S) was used to characterize the seasonal and interannual variability of the Rhodes Gyre’s ecosystem and to estimate an annual organic carbon budget over the 2013–2020 period. Comparisons of model outputs with satellite data and compiled in situ data from cruises and BioGeoChemical-Argo floats revealed the ability of the model to reconstruct the main seasonal and spatial biogeochemical dynamics of the Levantine Basin. The model results indicated that during the winter mixing period, phytoplankton first progressively grow sustained by nutrient supply. Then, short episodes of convection driven by heat loss and wind events, favoring nutrient injections, organic carbon export, and inducing light limitation on primary production, alternate with short episodes of phytoplankton growth. The estimate of the annual organic carbon budget indicated that the Rhodes Gyre is an autotrophic area with a positive net community production in the upper layer (0–150 m) amounting to 31.2 ± 6.9 g C m-2 year-1. Net community production in the upper layer is almost balanced over the seven-year period by physical transfers, (1) via downward export (16.8 ± 6.2 g C m-2 year-1) and (2) through lateral transport towards the surrounding regions (14.1 ± 2.1 g C m-2 year-1). The intermediate layer (150–400 m) also appears to be a source of organic carbon for the surrounding Levantine Sea (7.5 ± 2.8 g C m-2 year-1) mostly through the subduction of Levantine Intermediate Water following winter mixing. The Rhodes Gyre shows high interannual variability with enhanced primary production, net community production, and exports during years marked by intense heat losses and deep mixed layers. However, annual primary production appears to be only partially driven by winter vertical mixing. Based on our results, we can speculate that future increase of temperature and stratification could strongly impact the carbon fluxes in this region.
Published: 2022

15. Sponge Organic Matter Recycling: Reduced Detritus Production Under Extreme Environmental Conditions

Author: Maggioni, Federica, primary, Bell, James J., additional, Mireille, Pujo-Pay, additional, Megan, Shaffer, additional, Carlo, Cerrano, additional, Hugues, Lemonnier, additional, Yves, Letourneur, additional, and Riccardo, Rodolfo-Metalpa, additional
Published: 2022
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16. The Bouraké semi-enclosed lagoon (New Caledonia). A natural laboratory to study the life-long adaptation of a coral reef ecosystem to climate change-like conditions

Author: Federica Maggioni, Claude Payri, Carlo Cerrano, Yves Letourneur, Barbara Calcinai, Mireille Pujo-Pay, Riccardo Rodolfo-Metalpa, Jérome Aucan, and Francesca Benzoni
Subjects: geography, geography.geographical_feature_category, Benthic zone, Ecology, Environmental science, Climate change, Seawater, Ecosystem, Estuary, Coral reef, Mangrove, Reef
Abstract: According to current experimental evidence, coral reefs could disappear within the century if CO2 emissions remain unabated. However, recent discoveries of diverse and high cover reefs that already thrive under extreme conditions seem to contradict these projections. Volcanic CO2 vents, semi-enclosed lagoons and mangrove estuaries are unique study sites where one or more ecologically relevant parameters for life in the oceans are close or even worse than currently projected for the year 2100. These natural analogues of future conditions hold new hope for the future of coral reefs and provide unique natural laboratories to explore how reef species could keep pace with climate change. To achieve this, it is essential to characterize their environment as a whole, and accurately consider all possible environmental factors that may differ from what is expected in the future and that may possibly alter the ecosystem response. In this study, we focus on the semi-enclosed lagoon of Bouraké (New Caledonia, SW Pacific Ocean) where a healthy reef ecosystem thrives in warm, acidified and deoxygenated water. We used a multi-scale approach to characterize the main physical-chemical parameters and mapped the benthic community composition (i.e., corals, sponges, and macroalgae). The data revealed that most physical and chemical parameters are regulated by the tide, strongly fluctuate 3 to 4 times a day, and are entirely predictable. The seawater pH and dissolved oxygen decrease during falling tide and reach extreme low values at low tide (7.2 pHT and 1.9 mg O2 L−1 at Bouraké, vs 7.9 pHT and 5.5 mg O2 L−1 at reference reefs). Dissolved oxygen, temperature, and pH fluctuates according to the tide of up to 4.91 mg O2 L−1, 6.50 °C, and 0.69 pHT units on a single day. Furthermore, the concentration of most of the chemical parameters was one- to 5-times higher at the Bouraké lagoon, particularly for organic and inorganic carbon and nitrogen, but also for some nutrients, notably silicates. Surprisingly, despite extreme environmental conditions and altered seawater chemical composition, our results reveal a diverse and high cover community of macroalgae, sponges and corals accounting for 28, 11 and 66 species, respectively. Both environmental variability and nutrient imbalance might contribute to their survival under such extreme environmental conditions. We describe the natural dynamics of the Bouraké ecosystem and its relevance as a natural laboratory to investigate the benthic organism’s adaptive responses to multiple stressors like future climate change conditions.
Published: 2021

17. Supplementary material to 'The Bouraké semi-enclosed lagoon (New Caledonia). A natural laboratory to study the life-long adaptation of a coral reef ecosystem to climate change-like conditions'

Author: Federica Maggioni, Mireille Pujo-Pay, Jérome Aucan, Carlo Cerrano, Barbara Calcinai, Claude Payri, Francesca Benzoni, Yves Letourneur, and Riccardo Rodolfo-Metalpa
Published: 2021

18. Microbial Diversity and Activity During the Biodegradation in Seawater of Various Substitutes to Conventional Plastic Cotton Swab Sticks

Author: Justine Jacquin, Nolwenn Callac, Jingguang Cheng, Carolane Giraud, Yonko Gorand, Clement Denoual, Mireille Pujo-Pay, Pascal Conan, Anne-Leila Meistertzheim, Valerie Barbe, Stéphane Bruzaud, Jean-François Ghiglione, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Biopôle Clermont - Limagne, Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE [Réunion]), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut de Recherche pour le Développement (IRD), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Microbiology (medical), microbial colonization, Heterotroph, plastic biodegradation, Microbiology, law.invention, Biofouling, 03 medical and health sciences, chemistry.chemical_compound, Polylactic acid, law, biofouling, Food science, Cellulose, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, plastisphere, 030304 developmental biology, Original Research, 0303 health sciences, 030306 microbiology, Biofilm, Biodegradation, QR1-502, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, single-used plastics, Seawater, Cotton swab
Abstract: The European Parliament recently approved a new law banning single-use plastic items for 2021 such as plastic plates, cutlery, straws, cotton swabs, and balloon sticks. Transition to a bioeconomy involves the substitution of these banned products with biodegradable materials. Several materials such as polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), poly(butylene succinate) (PBS), polyhydroxybutyrate-valerate (PHBV), Bioplast, and Mater-Bi could be good candidates to substitute cotton swabs, but their biodegradability needs to be tested under marine conditions. In this study, we described the microbial life growing on these materials, and we evaluated their biodegradability in seawater, compared with controls made of non-biodegradable polypropylene (PP) or biodegradable cellulose. During the first 40 days in seawater, we detected clear changes in bacterial diversity (Illumina sequencing of 16S rRNA gene) and heterotrophic activity (incorporation of 3H-leucine) that coincided with the classic succession of initial colonization, growth, and maturation phases of a biofilm. Biodegradability of the cotton swab sticks was then tested during another 94 days under strict diet conditions with the different plastics as sole carbon source. The drastic decrease of the bacterial activity on PP, PLA, and PBS suggested no bacterial attack of these materials, whereas the bacterial activity in PBAT, Bioplast, Mater-Bi, and PHBV presented similar responses to the cellulose positive control. Interestingly, the different bacterial diversity trends observed for biodegradable vs. non-biodegradable plastics allowed to describe potential new candidates involved in the degradation of these materials under marine conditions. This better understanding of the bacterial diversity and activity dynamics during the colonization and biodegradation processes contributes to an expanding baseline to understand plastic biodegradation in marine conditions and provide a foundation for further decisions on the replacement of the banned single-used plastics.
Published: 2020

19. Mismatched dynamics of dissolved organic carbon and chromophoric dissolved organic matter in the coastal NW Mediterranean Sea

Author: Mireille Pujo-Pay, Elvia D. Sánchez-Pérez, Eva Ortega-Retuerta, Francesc Peters, Cèlia Marrasé, Pascal Conan, Ministerio de Economía y Competitividad (España), Consejo Nacional de Ciencia y Tecnología (México), Agencia Estatal de Investigación (España), Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chlorophyll a, Environmental Engineering, 010504 meteorology & atmospheric sciences, Meteorological events, 010501 environmental sciences, 01 natural sciences, chemistry.chemical_compound, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Rivers, Phytoplankton, Dissolved organic carbon, Mediterranean Sea, Environmental Chemistry, Photic zone, Ecosystem, Dissolved organic matter, 14. Life underwater, Waste Management and Disposal, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Abiotic component, Chlorophyll A, Fluorescent DOM, Chromophoric DOM, 15. Life on land, Spring bloom, Pollution, 6. Clean water, Carbon, Colored dissolved organic matter, chemistry, 13. Climate action, Environmental chemistry, Environmental science
Abstract: 9 pages, 7 figures, 3 tables, Coastal marine ecosystems are strongly influenced by different occasional events, such as intense winds, mixing, rain and river discharges. These events can directly or indirectly cause changes in dissolved organic matter (DOM) quality through a cascade of different biotic and abiotic processes. Changes in DOM quality are often associated with changes in DOM optical properties. Thus, examining the dynamics of chromophoric DOM (CDOM) can provide valuable information about biological and physical processes that have occurred in the ecosystem. Episodic meteorological events, particularly in temperate areas, appear very abruptly and induce very rapid responses; therefore, high time-resolved measurements are needed to capture them. We used a weekly sampling scheme to characterize DOM and nutrient dynamics in the NW Mediterranean coastal station ‘SOLA’. From February 2013 to April 2014, we measured several physical and chemical variables including temperature, salinity, inorganic nutrients, chlorophyll a dissolved organic carbon (DOC), CDOM and fluorescent DOM (FDOM). During this period, two extremely high fresh water intrusions greatly influenced the dynamics of some DOM fractions, in particular the FDOM. Inorganic nutrients and chlorophyll a showed seasonal patterns: A winter period characterized by a high nutrient concentration in surface waters favored the phytoplankton spring bloom; then, summer stratification extended until autumn. This stratification led to nutrient depletion and, consequently, lower chlorophyll a values in the photic zone. The CDOM and FDOM optical active fractions did not follow temporal trends similar to total DOC. This was likely because the potential sources and sinks of these DOM pools are microbial activity and light exposure, and these were acting simultaneously but in opposite directions. Interestingly, DOC exhibited the highest concentrations in summer, coinciding with nutrient and chlorophyll a minima. To explain this mismatch, we propose a sequence of abiotic and biotic phenomena that drive DOC temporal dynamics, This study was supported by the MERMeX/MISTRALS project and is a contribution to international SOLAS program and the projects ANIMA (CTM2015-65720-R) and DOREMI (CTM2012-34294) from the Spanish Ministerio de Economia y Competitividad. E.D. Sánchez-Pérez would like to thank the Consejo Nacional de Ciencia y Tecnologia (CONACyT) for their financial support through a PhD fellowship, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)
Published: 2020

20. Nutrient fluxes associated wth submarine groundwater discharge from karstic coastal aquifers (Côte Bleue, French Mediterranean Coastline)

Author: Emilie Le Roy, Olivier Crispi, Christelle Claude, Marc Souhaut, Pieter van Beek, Olivier Radakovitch, Mireille Pujo-Pay, Joseph Tamborski, Pascal Conan, Thomas Stieglitz, Claude Estournel, Simon Bejannin, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre for TropicalWater and Aquatic Ecosystem Research (TropWATER), School of Earth and Environmental Sciences [Australia], James Cook University (JCU)-James Cook University (JCU), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (IRSN/PSE-ENV/SRTE/LRTA), Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), and PSE-ENV/SRTE/LRTA
Subjects: Biogeochemical cycle, nutrient fluxes, 010504 meteorology & atmospheric sciences, submarine groundwater discharge, Aquifer, thermal infrared remote sensing, 010501 environmental sciences, 01 natural sciences, Mediterranean sea, radium isotopes, Groundwater discharge, 14. Life underwater, Transect, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, lcsh:Environmental sciences, 0105 earth and related environmental sciences, General Environmental Science, 2. Zero hunger, Hydrology, lcsh:GE1-350, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, 6. Clean water, Submarine groundwater discharge, GEOTRACES, 13. Climate action, Environmental science, Surface water, Groundwater
Abstract: Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the nearshore permeable sediments and coastal aquifer. Field work was conducted at different periods of the year to study the temporal variability of the chemical fluxes. Offshore transects of 223Ra and 224Ra were used to derive horizontal eddy diffusivity coefficients that were subsequently combined with surface water nutrient gradients (NO2− + NO3−, DSi) to determine the net nutrient fluxes from SGD. The estimated DSi and (NO2− + NO3−) fluxes are 6.2 ± 5.0 *103 and 4.0 ± 2.0 *103 mol d−1 per km of coastline, respectively. We attempted to further constrain these SGD fluxes by combining horizontal eddy diffusivity and 228Ra gradients. However, SGD endmember selection in this area (terrestrial groundwater discharge vs. porewater) adds further uncertainty to the flux calculation and thus prevented us from calculating a reliable flux using this latter method. Additionally, the relatively long half-life of 228Ra (5.75 y) makes it sensitive to specific circulation patterns in this coastal region, including sporadic intrusions of Rhône river waters that impact both the 228Ra and nutrient surface water distributions. We show that SGD nutrient fluxes locally reach up to 20 times the nutrient fluxes from a small river (Huveaune River). On a regional scale, DSi fluxes driven by SGD vary between 0.1 and 1.4% of the DSi inputs of the Rhône River, while the (NO2− + NO3−) fluxes driven by SGD on this 22 km long coastline are between 0.1 and 0.3% of the Rhône River inputs, the largest river that discharges into the Mediterranean Sea. Interestingly, the nutrient fluxes reported here are similar in magnitude compared with the fluxes quantified along the sandy beach of La Franqui, in the western Gulf of Lions (Tamborski et al., 2018), despite the different lithology of the two areas (karst systems vs. unconsolidated sediment).
Published: 2020

21. Submarine karstic springs as a source of nutrients and bioactive trace metals for the oligotrophic Northwest Mediterranean Sea

Author: Jean-Luc Seidel, Joseph Tamborski, Pascal Conan, Marc Souhaut, Pieter van Beek, Marc Diego-Feliu, Jean-François Ghiglione, Armand Szafran, Mireille Pujo-Pay, Charlène Odobel, Jordi Garcia-Orellana, Bruno Arfib, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Hydrosciences Montpellier (HSM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Service National d'Observation sur le KARST (SNO Karst), Institut national des sciences de l'Univers (INSU - CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Universitat Autònoma de Barcelona (UAB), FEDER - Europe and Region Occitanie Pyrenees-Mediterranee (SELECT project)Generalitat de Catalunya2018 SGR-1588, ANR-15-CE01-0004,MED-SGD,Décharges d'eau souterraine en mer : étude d'une source cachée d'éléments chimiques à l'océan(2015), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Subjects: 0106 biological sciences, Submarine groundwater discharge, Environmental Engineering, 010504 meteorology & atmospheric sciences, Radium isotopes, Karst, Aquifer, 01 natural sciences, Mediterranean sea, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Spring (hydrology), Environmental Chemistry, Trace metal, 14. Life underwater, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Hydrology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, Baseflow, 010604 marine biology & hydrobiology, Nutrients, 15. Life on land, Pollution, [SDE.ES]Environmental Sciences/Environmental and Society, 6. Clean water, Springs, GEOTRACES, 13. Climate action, Environmental science, Seawater, Groundwater
Abstract: International audience; Groundwater springs in karstified carbonate aquifers are known to transport carbon, nutrients and trace elements to the coastal ocean. The biogeochemical significance of submarine karstic springs and their impact on coastal primary production are often difficult to quantify. We investigated several karstic springs, including the first-order Port-Miou spring, in an urbanized watershed that is also severely impacted by sewage effluent (Calanques of Marseille-Cassis, France). Karstic springs were elevated in major nutrients and bioactive trace metals over Mediterranean seawater, with relatively low concentration ranges. Groundwater NO3- was likely derived from atmosphere-aquifer interactions, while DOC:DON ratios reveal that NO2- and NH4+ was autochthonously produced during mixing between karst groundwater and seawater. Submarine groundwater discharge (SGD) during March 2018 (wet season, baseflow conditions) was 6.7 ± 2.0 m3 s-1 for the entire investigated coastline, determined from simultaneous 224Ra and 226Ra mass balances. The contribution of groundwater PO43-, the major limiting nutrient of the Mediterranean Sea, sustained only 1% of primary production adjacent to sewage outfall, but between 7 and 100% of the local primary production in areas that were not impacted by sewage. Groundwater and seawater Fe:DIN and Fe:DIP ratios suggest that Fe was not a limiting micro-nutrient during the period of study, where bioactive trace metal fluxes were dominated by sewage and atmospheric deposition, although excess Fe from groundwater may locally enhance N fixation. Groundwater solute fluxes may easily vary by a factor of two or more over time because karst aquifers are sensitive to precipitation, as is the case of the regional carbonate karstified aquifer of Port-Miou, highlighting the critical importance of properly characterizing nutrient and trace metal inputs in these coastal environments.
Published: 2020

22. Programmed cell death in diazotrophs and the fate of organic matter in the western tropical South Pacific Ocean during the OUTPACE cruise

Author: Dina Spungin, Nathalie Leblond, Cécile Dupouy, Natalia Belkin, Marcus Stenegren, Rachel A. Foster, Sophie Bonnet, Mireille Pujo-Pay, Ilana Berman-Frank, Andrea Caputo, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: 0106 biological sciences, Chlorophyll a, 010504 meteorology & atmospheric sciences, lcsh:Life, 01 natural sciences, chemistry.chemical_compound, lcsh:QH540-549.5, Phytoplankton, Organic matter, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, Earth-Surface Processes, South Pacific Gyre, 0105 earth and related environmental sciences, chemistry.chemical_classification, Biomass (ecology), biology, 010604 marine biology & hydrobiology, lcsh:QE1-996.5, biology.organism_classification, lcsh:Geology, lcsh:QH501-531, Oceanography, Trichodesmium, chemistry, 13. Climate action, [SDE]Environmental Sciences, Environmental science, Diazotroph, lcsh:Ecology, Bloom
Abstract: The fate of diazotroph (N2 fixers) derived carbon (C) and nitrogen (N) and their contribution to vertical export of C and N in the western tropical South Pacific Ocean was studied during OUTPACE (Oligotrophy to UlTra-oligotrophy PACific Experiment). Our specific objective during OUTPACE was to determine whether autocatalytic programmed cell death (PCD), occurring in some diazotrophs, is an important mechanism affecting diazotroph mortality and a factor regulating the vertical flux of organic matter and, thus, the fate of the blooms. We sampled at three long duration (LD) stations of 5 days each (LDA, LDB and LDC) where drifting sediment traps were deployed at 150, 325 and 500 m depth. LDA and LDB were characterized by high chlorophyll a (Chl a) concentrations (0.2–0.6 µg L−1) and dominated by dense biomass of the filamentous cyanobacterium Trichodesmium as well as UCYN-B and diatom–diazotroph associations (Rhizosolenia with Richelia-detected by microscopy and het-1 nifH copies). Station LDC was located at an ultra-oligotrophic area of the South Pacific gyre with extremely low Chl a concentration (∼ 0.02 µg L−1) with limited biomass of diazotrophs predominantly the unicellular UCYN-B. Our measurements of biomass from LDA and LDB yielded high activities of caspase-like and metacaspase proteases that are indicative of PCD in Trichodesmium and other phytoplankton. Metacaspase activity, reported here for the first time from oceanic populations, was highest at the surface of both LDA and LDB, where we also obtained high concentrations of transparent exopolymeric particles (TEP). TEP were negatively correlated with dissolved inorganic phosphorus and positively coupled to both the dissolved and particulate organic carbon pools. Our results reflect the increase in TEP production under nutrient stress and its role as a source of sticky carbon facilitating aggregation and rapid vertical sinking. Evidence for bloom decline was observed at both LDA and LDB. However, the physiological status and rates of decline of the blooms differed between the stations, influencing the amount of accumulated diazotrophic organic matter and mass flux observed in the traps during our experimental time frame. At LDA sediment traps contained the greatest export of particulate matter and significant numbers of both intact and decaying Trichodesmium, UCYN-B and het-1 compared to LDB where the bloom decline began only 2 days prior to leaving the station and to LDC where no evidence for bloom or bloom decline was seen. Substantiating previous findings from laboratory cultures linking PCD to carbon export in Trichodesmium, our results from OUTPACE indicate that nutrient limitation may induce PCD in high biomass blooms such as displayed by Trichodesmium or diatom–diazotroph associations. Furthermore, PCD combined with high TEP production will tend to facilitate cellular aggregation and bloom termination and will expedite vertical flux to depth.
Published: 2018

23. Open-ocean convection process: A driver of the winter nutrient supply and the spring phytoplankton distribution in the Northwestern Mediterranean Sea

Author: Mathieu Rembauville, Pascal Conan, Jocelyne Caparros, Jean-François Ghiglione, Claude Estournel, Louise Oriol, Fayçal Kessouri, Fabrizio D'Ortenzio, Caroline Ulses, Vincent Taillandier, Elvia D. Sanchez-Perez, Xavier Durrieu de Madron, Tatiana Severin, Mireille Pujo-Pay, and Nicolas Mayot
Subjects: 0106 biological sciences, Convection, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Spring bloom, Oceanography, 01 natural sciences, Geophysics, Mediterranean sea, Water column, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Nanophytoplankton, Phytoplankton, Convective mixing, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, Geology, 0105 earth and related environmental sciences
Abstract: This study was a part of the DeWEX project (Deep Water formation EXperiment), designed to better understand the impact of dense water formation on the marine biogeochemical cycles. Here, nutrient and phytoplankton vertical and horizontal distributions were investigated during a deep open-ocean convection event and during the following spring bloom in the Northwestern Mediterranean Sea (NWM). In February 2013, the deep convection event established a surface nutrient gradient from the center of the deep convection patch to the surrounding mixed and stratified areas. In the center of the convection area, a slight but significant difference of nitrate, phosphate and silicate concentrations was observed possibly due to the different volume of deep waters included in the mixing or to the sediment resuspension occurring where the mixing reached the bottom. One of this process, or a combination of both, enriched the water column in silicate and phosphate, and altered significantly the stoichiometry in the center of the deep convection area. This alteration favored the local development of microphytoplankton in spring, whereas nanophytoplankton dominated neighboring locations where the convection reached the deep layer but not the bottom. This study shows that the convection process influences both winter nutrients distribution and spring phytoplankton distribution and community structure. Modifications of the convection spatial scale and intensity (i.e. convective mixing depth) is likely to have strong consequences on phytoplankton community structure and distribution in the NWM, and thus on the marine food web.
Published: 2017

24. Deep sediment resuspension and thick nepheloid layer generation by open-ocean convection

Author: Anthony Bosse, Jean-François Ghiglione, S. Kunesch, Patrick Marsaleix, N. Delsaut, Loïc Houpert, C. Curtil, Tatiana Severin, Léo Berline, Lionel Guidi, Pierre Testor, Mireille Pujo-Pay, Pascal Conan, X. Durrieu de Madron, Séverine Martini, Simon Ramondenc, and Christian Tamburini
Subjects: 0106 biological sciences, Convection, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Nepheloid layer, Lead (sea ice), Sediment, Particulates, Oceanography, Mooring, 01 natural sciences, Bathyal zone, Geophysics, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, Sediment transport, Geology, 0105 earth and related environmental sciences
Abstract: The Gulf of Lions in the northwestern Mediterranean is one of the few sites around the world ocean exhibiting deep open‐ocean convection. Based on 6 year long (2009–2015) time series from a mooring in the convection region, shipborne measurements from repeated cruises, from 2012 to 2015, and glider measurements, we report evidence of bottom thick nepheloid layer formation, which is coincident with deep sediment resuspension induced by bottom‐reaching convection events. This bottom nepheloid layer, which presents a maximum thickness of more than 2000 m in the center of the convection region, probably results from the action of cyclonic eddies that are formed during the convection period and can persist within their core while they travel through the basin. The residence time of this bottom nepheloid layer appears to be less than a year. In situ measurements of suspended particle size further indicate that the bottom nepheloid layer is primarily composed of aggregates between 100 and 1000 µm in diameter, probably constituted of fine silts. Bottom‐reaching open ocean convection, as well as deep dense shelf water cascading that occurred concurrently some years, lead to recurring deep sediments resuspension episodes. They are key mechanisms that control the concentration and characteristics of the suspended particulate matter in the basin, and in turn affect the bathypelagic biological activity
Published: 2017

25. Multicontamination phenomena occur more often than expected in Mediterranean coastal watercourses: Study case of the Têt River (France)

Author: Dominique Aubert, Olivier Verneau, Jennifer Sola, Christophe Menniti, Mireille Pujo-Pay, Carmen Palacios, Brice Reoyo-Prats, Wolfgang Ludwig, Pascal Conan, Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), and Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Mediterranean climate, Têt river, Environmental Engineering, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, 010501 environmental sciences, 01 natural sciences, pollution of watercourses, Contaminants, 11. Sustainability, Environmental Chemistry, Waste Management and Disposal, 0105 earth and related environmental sciences, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Hydrology, Pollutant, Storm, Particulates, [SDE.ES]Environmental Sciences/Environmental and Society, Pollution, 6. Clean water, [SDU]Sciences of the Universe [physics], 13. Climate action, Mediterranean sea Southeast France, Environmental science, Combined sewer, rainfalls and floods, Water quality, Surface runoff, Surface water
Abstract: International audience; Contaminants found in watercourses are not only the result of anthropogenic activities but also depend on river's seasonal hydrodynamics. This is particularly true in Mediterranean climate regions where long dry periods are interrupted by strong rainfalls. Storm events remobilize particles from soils and sediments and, as a consequence, the load of particulate matter in rivers can be quite considerable, severely affecting water quality. Nevertheless, an absence of fieldwork studies exists concerning the simultaneous dynamics of mixtures of pollutants in river waters, particularly during strong rainfalls and floods. Our study assessed the concentrations of six families of pollutants, including pesticides, at these events, and compared them to those observed at drought sampling periods. We have used as model a typical Mediterranean coastal river from Southeast France, the Têt River, whose hydrodynamics and major elements fluxes have been fairly investigated. As expected, our results show that chemical mixtures due to human activities occur and that they are particularly relevant during storm events. But the results of our study argue that exceptional multicontamination phenomena actually happen more often than expected because they are linked to recurrent sudden intense rainfall events in the Mediterranean. In particular, combined sewer overflows are responsible for this major issue in urbanized areas, whereas runoff and leaching will be the most important sources of pollutant mixtures occurring at flood flow peak. After an overview of the sources responsible for chronic multiple stressors events in regions under a Mediterranean climate regime worldwide, we revisit best management measures to reduce risks from the presence of chemical mixtures in the environment.
Published: 2017

26. Aerosol inputs affect the optical signatures of dissolved organic matter in NW Mediterranean coastal waters

Author: Laura Fernández-González, Isabel Marín, Francesc Peters, Pascal Conan, Mireille Pujo-Pay, E. Denisse Sánchez-Pérez, Cèlia Marrasé, Fran L. Aparicio, Sdena Nunes, Consejo Nacional de Ciencia y Tecnología (México), European Commission, and Ministerio de Economía y Competitividad (España)
Subjects: 0106 biological sciences, Mediterranean climate, 010504 meteorology & atmospheric sciences, SH1-691, DOC, Aquatic Science, Mineral dust, Oceanography, Mar Mediterráneo, 01 natural sciences, lcsh:Aquaculture. Fisheries. Angling, Nutrient, Dissolved organic carbon, FDOM, Mediterranean Sea, Aquaculture. Fisheries. Angling, Aerosol deposition, Organic matter, mediterranean sea, 0105 earth and related environmental sciences, lcsh:SH1-691, chemistry.chemical_classification, Ecology, fdom, 010604 marine biology & hydrobiology, doc, Aerosol, Deposición de aerosoles, chemistry, Environmental chemistry, Environmental science, Aeolian processes, Surface water, aerosol deposition
Abstract: 10 pages, 6 figures, 1 table, [EN] Aeolian inputs of organic and inorganic nutrients to the ocean are important as they can enhance biological production in surface waters, especially in oligotrophic areas like the Mediterranean. The Mediterranean littoral is particularly exposed to both anthropogenic and Saharan aerosol depositions on a more or less regular basis. During the last few decades experimental studies have been devoted to examining the effect of inorganic nutrient inputs from dust on microbial activity. In this study, we performed experiments at two different locations of the NW Mediterranean, where we evaluated the changes in the quality and quantity of dissolved organic matter due to atmospheric inputs of different origin (Saharan and anthropogenic) and its subsequent transformations mediated by microbial activities. In both experiments the humic-like and protein-like substances, and the fluorescence quantum yield increased after addition. In general, these changes in the quality of dissolved organic matter did not significantly affect the prokaryotes. The recalcitrant character of the fluorescent dissolved organic matter (FDOM) associated with aerosols was confirmed, as we found negligible utilization of chromophoric compounds over the experimental period. We framed these experiments within a two-year time series data set of atmospheric deposition and coastal surface water analyses. These observations showed that both Saharan and anthropogenic inputs induced changes in the quality of organic matter, increasing the proportion of FDOM substances. This increase was larger during Saharan dust events than in the absence of Saharan influence, [ES] Los aportes atmosféricos de nutrientes orgánicos e inorgánicos al océano son importantes ya que pueden aumentar la producción biológica en aguas superficiales, especialmente en las zonas oligotróficas como el Mediterráneo. El litoral del Mediterráneo está particularmente expuesto a aportes de origen antropogénico y a deposiciones de polvo sahariano de forma más o menos regular. Durante las últimas décadas los estudios experimentales se han dedicado, sobre todo, a examinar el efecto de la entrada de nutrientes inorgánicos atmosféricos sobre la actividad microbiana. En este estudio, se realizaron experimentos con comunidades microbianas procedentes de dos zonas del Mediterráneo noroccidental. Se evaluaron los cambios en la calidad y cantidad de la materia orgánica disuelta debido a aportes atmosféricos de distinto origen y sus posteriores transformaciones mediadas por actividades microbianas. En ambos experimentos las sustancias orgánicas fluorescentes y el rendimiento cuántico de fluorescencia aumentaron después de la adición de material atmosférico. En general, estos cambios en la calidad de la materia orgánica no afectaron significativamente a los organismos procariotas. El carácter recalcitrante de la materia orgánica disuelta fluorescente (FDOM) contenida en los aerosoles se confirmó ya que la utilización de compuestos cromóforos durante el período experimental fue insignificante. Los resultados obtenidos se contextualizan en relación con una serie temporal de dos años de datos adquiridos de deposición atmosférica y análisis de agua superficial costera. La variabilidad temporal de estas dos variables mostró que tanto los aportes saharianos como antropogénicos provocaron cambios en la calidad de la materia orgánica disuelta en aguas superficiales, incrementando la fracción fluorescente. Éste aumento resultó ser mayor durante eventos de polvo sahariano que en ausencia de ellos, This study was supported by the projects 1179-1198. ADEPT (CTM2011-23458), DOREMI (CTM2012-342949) and ANIMA (CTM2015-65720-R MINECO/FEDER, UE). E.D. Sánchez-Pérez would like to thank the Consejo Nacional de Ciencia y Tecnologia (CONACyT) for their financial support through a PhD fellowship. I. Marín thanks the FPI Spanish scholarship programme for its support (BES 2012-052976)
Published: 2016
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27. Spatiotemporal variability in Terminos Lagoon (Mexico) waters during the 2009–2010 drought reveals upcoming trophic status shift in response to climate change

Author: Montserrat Origel-Moreno, Pascal Conan, Francisco José Gutiérrez Mendieta, Christian Grenz, Jorge Zavala-Hidalgo, Alain Muñoz Caravaca, Jean-François Ghiglione, Mireille Pujo-Pay, Sandrine Chifflet, Lionel Denis, Adolfo Contreras Ruiz Esparza, Renaud Fichez, Pascal Douillet, Carlos Linares, 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), Université de Sherbrooke (UdeS), Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México (UNAM), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS), Caractérisation et modélisation des échanges dans des lagons soumis aux influences terrigènes et anthropiques (CAMELIA), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Institut de Recherche pour le Développement (IRD [Guyane]), Universidad Autónoma Metropolitana [Mexico] (UAM), Universidad Autonoma Metropolitana, Unidad Cuajimalpa, Centro de Ciencias de la Atmosfera [Mexico], 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 national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), and Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord])
Subjects: 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Climate change, 010501 environmental sciences, 01 natural sciences, Trophic status, Hydrology (agriculture), 14. Life underwater, El Niño, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Mexico, Global change, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Trophic level, Global and Planetary Change, Community structure, Sampling (statistics), Biota, 15. Life on land, Coastal lagoon, 6. Clean water, Salinity, Oceanography, 13. Climate action, Environmental science, Hydrology, El Nino
Abstract: International audience; The 2009-2010 El Niño was accompanied by a severe drought strongly impacting Mexico as well as Central America, the Caribbean, and the southern USA. The present work aims at assessing how such a major climatic event impacted the hydrological typology of transitional waters in Terminos Lagoon, one of the largest shallow tropical lagoons fringing the Gulf of Mexico. Spatiotemporal inter-comparison of hydrological conditions was conducted by pairing a reference multiparametric dataset (14 hydrological parameters versus 34 sampling stations) averaged over the October 2008 to July 2010 period with each sampling occurrence dataset and running Principal Component Analyses (PCA), setting the reference-survey dataset as active variables and each sampling occurrence dataset as non-active (supplementary) variables. It revealed that the exceptional deficit in freshwater supply to the lagoon during the 2009-2010 El Niño drastically reduced hydrological diversity and lowered the trophic status of the lagoon. Short-term shifts in environmental status are common in transitional waters and responsible for temporary shifts in community structure but climate change projections show a significant long-term decrease in the freshwater discharge at the regional scale that will impact Terminos Lagoon as well as other coastal lagoons of Mexico and Central America. When combined with sea level rise, such a decrease will result in a long-term shift in hydrological conditions with a subsequent increase in salinity and a decrease in the diversity of environmental conditions affecting trophic status, will have a long-term impact on the biota.
Published: 2019

28. The composition and distribution of semi-labile dissolved organic matter across the southwest Pacific

Author: Christos Panagiotopoulos, Mireille Pujo-Pay, Mar Benavides, France van Wambeke, Richard Sempere, 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), Laboratoire d'océanographie biologique de Banyuls (LOBB), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: South west Pacific, lcsh:QE1-996.5, lcsh:Life, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, GEOF, lcsh:Geology, lcsh:QH501-531, [SDU]Sciences of the Universe [physics], lcsh:QH540-549.5, OUTPACE, Dissolved organic matter, lcsh:Ecology, Carbohydrates/chemistry, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Abstract: The distribution and dynamics of dissolved organic carbon (DOC) and dissolved combined neutral sugars (DCNS) were studied across an increasing oligotrophic gradient (18 to 22∘ S latitude) in the tropical South Pacific Ocean, spanning from the Melanesian Archipelago (MA) area to the western part of the South Pacific gyre (WGY), in austral summer as a part of the OUTPACE project. Our results show that DOC and DCNS concentrations exhibited no statistical differences between the MA and WGY areas (0–200 m: 47–81 µM C for DOC and 0.2-4.2 µM C for DCNS). However, due to a deepening of the euphotic zone, a deeper penetration of DOC was noticeable at 150 m of depth at the WGY area. Excess DOC (DOCEX) was determined as the difference between surface and deep-sea DOC values, and euphotic zone integrated stocks of both DOC and DOCEX were higher in the WGY than the MA area. Considering DOCEX as representative of semi-labile DOC (DOCSL), its residence time was calculated as the ratio of DOCSL to bacterial carbon demand (BCD). This residence time was 176±43 days (n=3) in the WGY area, about 3 times longer than in the MA area (Tr=51±13 days, n=8), suggesting an accumulation of semi-labile dissolved organic matter (DOM) in the surface waters of WGY. Average epipelagic (0–200 m) DCNS yields (DCNS × DOC−1) based on volumetric data were roughly similar in both areas, accounting for ∼2.8 % of DOC. DCNS exhibited a longer residence time in WGY (Tr=91±41 days, n=3) than in MA (Tr=31±10 days, n=8), further suggesting that this DCNS pool persists longer in the surface waters of the WGY. The accumulation of DOCEX in the surface waters of WGY is probably due to very slow bacterial degradation due to nutrient and/or energy limitation of heterotrophic prokaryotes, indicating that biologically produced DOC can be stored in the euphotic layer of the South Pacific gyre for a long period.
Published: 2019

29. Impact of an intense water column mixing (0-1500 m) on prokaryotic diversity and activities during an open-ocean convection event in the NW Mediterranean Sea

Author: Caroline Sauret, Christian Tamburini, Xavier Durrieu de Madron, Fayçal Kessouri, Mehdi Boutrif, Pascal Conan, Tatiana Severin, Jean-François Ghiglione, Jocelyne Caparros, Thomas Duhaut, Marc Garel, Louise Oriol, and Mireille Pujo-Pay
Subjects: 0106 biological sciences, chemistry.chemical_classification, Convection, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Ecology, 010604 marine biology & hydrobiology, Pelagic zone, Biology, 01 natural sciences, Microbiology, Water column, Mediterranean sea, Oceanography, chemistry, Seawater, Organic matter, Thermohaline circulation, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract: Open-ocean convection is a fundamental process for thermohaline circulation and biogeochemical cycles that causes spectacular mixing of the water column. Here, we tested how much the depth-stratified prokaryotic communities were influenced by such an event, and also by the following re-stratification. The deep convection event (0-1500 m) that occurred in winter 2010-2011 in the NW Mediterranean Sea resulted in a homogenization of the prokaryotic communities over the entire convective cell, resulting in the predominance of typical surface Bacteria, such as Oceanospirillale and Flavobacteriales. Statistical analysis together with numerical simulation of vertical homogenization evidenced that physical turbulence only was not enough to explain the new distribution of the communities, but acted in synergy with other parameters such as exported particulate and dissolved organic matters. The convection also stimulated prokaryotic abundance (+21%) and heterotrophic production (+43%) over the 0-1500 m convective cell, and resulted in a decline of cell-specific extracellular enzymatic activities (-67%), thus suggesting an intensification of the labile organic matter turnover during the event. The rapid re-stratification of the prokaryotic diversity and activities in the intermediate layer 5 days after the intense mixing indicated a marked resilience of the communities, apart from the residual deep mixed water patch.
Published: 2016

30. The composition and distribution of labile dissolved organic matter across the south west Pacific

Author: Christos Panagiotopoulos, Mireille Pujo Pay, Mar Benavides, France Van Wambeke, and Richard Sempéré
Abstract: The distribution and dynamics of dissolved organic carbon (DOC) and dissolved combined neutral sugars (DCNS) were studied across an increasing oligotrophic gradient (−18 to −22° N latitude) spanning from the Melanesian Archipelago (MA) area to the western part of the south Pacific gyre (WGY), in austral summer, as a part of the OUTPACE project. Our results showed DOC and DCNS concentrations exhibited little differences among the MA and WGY areas (0–200 m: 55–78 µMC for DOC and 1.5–2 µMC for DCNS), however, a deeper penetration of DOC was noticeable at 150 m depth at the WGY area. This finding was also reflected to the DOC and semi-labile DOC (DOCSL) stocks values (integration 0–200 m) for which we found higher values in the WGY than the MA area. The high excess DOCSL measured in WGY was characterized by a high residence time (130 ± 31 days (n = 3)) about three times higher than the MA region (Tr = 40 ± 7 days (n = 8)) suggesting an accumulation of the semi-labile DOM in the surface waters of WGY. DCNS yields (DCNS-C x DOC−1 %) also followed this pattern with higher values recorded in the WGY (3.2 ± 1.3 %) than MA (2.8 ± 0.8 %) highlighting the presence of semi-labile dissolved organic material (DOM) in the form of polysaccharides. These polysaccharides also exhibited a higher residence time in WGY (Tr = 8 ± 4 days, n = 3) than in MA (Tr = 3 ± 1days, n = 8) suggesting that this DCNS pool persists longer in the surface waters of the WGY. The accumulation of DOCSL in the surface waters of WGY is probably due to the very slow bacterial degradation due to nutrient limitation indicating that biologically produced DOC can be stored in the euphotic layer for a very long period.
Published: 2018

31. Dynamics of particulate organic matter composition in coastal systems: Forcing of spatio-temporal variability at multi-systems scale

Author: Philippe Pineau, Aurore Gueux, Martine Bréret, Sophie Ferreira, Muriel Crouvoisier, Cédric Leroux, Pascal Claquin, Francois Dindinaud, Peggy Rimmelin-Maury, Camilla Liénart, Elsa Breton, Gaël Guillou, Pascal Conan, Mireille Pujo-Pay, Patrick Raimbault, Franck Petit, Béatrice Lauga, Emilie Grossteffan, Nicolas Susperregui, Michel Lafont, Paco Rodriguez Tress, Véronique Lagadec, Emmanuelle Sultan, Eric Maria, Pierre-Guy Sauriau, Yann Bozec, Julien Guillaudeau, Jézabel Lamoureux, Sandrine Geslin, Fabien Aubert, Orianne Jolly, Anne-Marie Corre, Nicolas Savoye, Maïa Durozier, Laurence Costes, Eric Feunteun, Sabrina Bichon, Stéphane L'Helguen, Eric Macé, Benoit Lebreton, Nicolas Lachaussée, Christophe Boinet, Valérie David, Vincent Marieu, Laure Mousseau, Jocelyne Caparros, Hervé Derriennic, Yolanda Del Amo, Vanessa Rouaud, Jean-Paul Lehodey, Sébastien Aubin, Robert Duran, Thierry Cariou, Nicole Garcia, Line Bourasseau, Pierre Ramond, Vincent Hanquiez, Eric Lecuyer, Jérémy Devesa, Antoine Nowaczyk, UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Dynamiques de l'Environnement Côtier (DYNECO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Environnements et Paléoenvironnements OCéaniques (EPOC), Centre De Recherche et d'Enseignement sur les Systèmes Côtiers (CRESCO), Station marine Dinard, Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), CHImie Marine (CHIM), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Nutrition et Neurobiologie intégrée (NutriNeuro), Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Ecole nationale supérieure de chimie, biologie et physique, Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Villefranche-sur-mer (OOVM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), 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), 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 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), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie et de biogéochimie (LOB), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Centre de recherches en environnement côtier (CREC), Université de Caen Normandie (UNICAEN), Institut des Milieux Aquatiques, PERMALA-LIGA, funded by the Aquitaine Regional Council, EC2CO-DRIL MOSLIT, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Dynamiques des Écosystèmes Côtiers (DYNECO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Adaptation et diversité en milieu marin (ADMM), Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche de Roscoff (FR2424), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Ecole nationale supérieure de chimie, biologie et physique, 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), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut de Recherche pour le Développement (IRD), Analytical, Environmental and Geo- Chemistry, Vrije Universiteit [Brussels] (VUB), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université de Lille-Université du Littoral Côte d'Opale-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Universitaire Européen de la Mer (IUEM), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Nutrition et Neurobiologie intégrée (NutriNeur0), Ecole nationale supérieure de chimie, biologie et physique-Institut Polytechnique de Bordeaux-Université Sciences et Technologies - Bordeaux 1-Institut National de la Recherche Agronomique (INRA)-Université Bordeaux Segalen - Bordeaux 2, Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Evolution des Systèmes Naturels et Modifiés (LESNM), Muséum national d'Histoire naturelle (MNHN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Centre de recherche et d'enseignement des systèmes côtiers (CRESCO), Muséum national d'Histoire naturelle (MNHN), UMS 3113, Institut Universitaire Européen de la Mer (IUEM), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO), Qualité des eaux et prévention des pollutions (UR QELY), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Station Marine, Université de Lille, Sciences et Technologies-PRES Université Lille Nord de France-Centre National de la Recherche Scientifique (CNRS), Sorbonne Universités, Centre d'Analyse et d'Intervention Sociologiques (CADIS), École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS), EMBIO, Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Laboratoire Biens, Normes, Contrats (LBNC), Avignon Université (AU), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Pau et des Pays de l'Adour (UPPA), Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Pau et des Pays de l'Adour (UPPA), 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)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Environmental forcing, Forcing (mathematics), Aquatic Science, 01 natural sciences, Water column, Particulate organic matter, Phytoplankton, medicine, Coastal systems, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Trophic level, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, 010604 marine biology & hydrobiology, ACL, Geology, Estuary, Seasonality, medicine.disease, Meta-analysis, Oceanography, 13. Climate action, Benthic zone, [SDE]Environmental Sciences, Environmental science, Sedimentary rock, France, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: International audience; In costal systems, particulate organic matter (POM) results from a multiplicity of sources having their respective dynamics in terms of production, decomposition, transport and burial. The POM pool experiences thus considerable spatial and temporal variability. In order to better understand this variability, the present study employs statistical multivariate analyses to investigate links between POM composition and environmental forcings for a panel of twelve coastal systems distributed along the three maritime regions of France and monitored weekly to monthly for 1 to 8 years.At multi-system scale, two main gradients of POC composition have been identified: a 'Continent-Ocean' gradient associated with hydrodynamics, sedimentary dynamics and depth of the water column, and a gradient of trophic status related to nutrient availability. At local scale, seasonality of POC composition appears to be station-specific but still related to part of the above-mentioned forcings. A typology of systems was established by coupling spatial and temporal variability of POC composition. Four groups were highlighted: (1) the estuarine stations where POC composition is dominated by terrestrial POM and driven by hydrodynamics and sedimentary processes, (2) the oligotrophic systems, characterized by the contribution of diazotrophs due to low nutrient availability, and the marine meso/eutroph systems whose POC composition is (3) either deeply dominated by phytoplankton or (4) dominated by phytoplankton but where the contribution of continental and benthic POC is not negligible and is driven by hydrodynamics, sedimentary processes and the height of the water column.Finally, the present study provides several insights into the different forcings to POM composition and dynamics in temperate coastal systems at local and multi-system scales. This work also presents a methodological approach that establishes statistical links between forcings and POM composition, helping to gain more objectively insight of forcings.
Published: 2018

32. Supplementary material to 'Programmed cell death in diazotrophs and the fate of organic matter in the Western Tropical South Pacific Ocean during the OUTPACE cruise'

Author: Dina Spungin, Natalia Belkin, Rachel Foster, Marcus Stenegren, Andrea Caputo, Mireille Pujo-Pay, Nathalie Leblond, Cecile Dupouy, Sophie Bonnet, and Ilana Berman-Frank
Published: 2018

33. Dynamics of phytoplankton and heterotrophic bacterioplankton in the western tropical South Pacific Ocean along a gradient of diversity and activity of diazotrophs

Author: France Van Wambeke, Audrey Gimenez, Solange Duhamel, Cécile Dupouy, Dominique Lefevre, Mireille Pujo-Pay, and Thierry Moutin
Subjects: 0106 biological sciences, Deep chlorophyll maximum, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, biology, 010604 marine biology & hydrobiology, Primary production, New production, biology.organism_classification, 01 natural sciences, Oceanography, Ocean gyre, Phytoplankton, Environmental science, Photic zone, Prochlorococcus, Bloom, 0105 earth and related environmental sciences
Abstract: Heterotrophic prokaryotic production (BP) was studied in the Western Tropical South Pacific using the leucine technique. Integrated over the euphotic zone, BP ranged from 58–120 mg C m−2 d−1 within the Melanesian Archipelago, and from 31–50 mg C m−2 within the subtropical gyre. Nitrogen was often one of the main factor controlling BP on short time scale as shown using enrichment experiments, followed by dissolved inorganic phosphate (DIP) near the surface and labile organic carbon deeper in the euphotic zone. With N2 fixation being one of the most important fluxes fueling new production, we explored relationships between BP, primary production (PP) and N2 fixation rates. BP variability was better explained by the variability of N2 fixation rates than by that of PP in surface waters of the Melanesian Archipelago, which were characterized by N depleted layers, and low DIP turnover times (TDIP < 100 h). However, BP was more significantly correlated with PP but not with N2 fixation rates where DIP was more available (TDIP > 100 h), i.e. in a layer deeper than the euphotic zone -including the deep chlorophyll maximum depths- in the Melanesian Archipelago, or within the entire euphotic zone in the subtropical gyre. Bacterial growth efficiency (BGE) ranged from 6–10 %. Applying correcting factors to estimate gross primary production and correcting BP for Prochlorococcus assimilation of leucine, we showed a large variability in the contribution of gross primary production to bacterial C demand. Exploration of a bloom collapse at one site south of Vanuatu showed the importance of blooms, which can persist over extensive distance for long periods of time, and can maintaining net autotrophy where they occur. Using a Lagragian sampling strategy during 6 days, long duration sites allowed for the study of the rapid changes including BP, primary production and BGE, that occurred during the bloom collapse.
Published: 2018

34. Aphotic N2 fixation along an oligotrophic to ultraoligotrophic transect in the Western Tropical South Pacific Ocean

Author: Mar Benavides, Katyanne M. Shoemaker, Pia H. Moisander, Jutta Niggemann, Thorsten Dittmar, Solange Duhamel, Olivier Grosso, Mireille Pujo-Pay, Sandra Hélias-Nunige, and Sophie Bonnet
Subjects: 14. Life underwater
Abstract: The western tropical South Pacific (WTSP) Ocean has been recognized as a global hotspot of dinitrogen (N2) fixation. Here, as in other marine environments across the oceans, N2 fixation studies have focused in the sunlit layer. However, studies have confirmed the importance of aphotic N2 fixation activity, although until now only one had been performed in the WTSP. In order to increase our knowledge of aphotic N2 fixation in the WTSP, here we measure N2 fixation rates and identify diazotrophic phylotypes in the mesopelagic layer along a transect spanning from New Caledonia to French Polynesia. Because non-cyanobacterial diazotrophs presumably need external dissolved organic matter (DOM) sources for their nutrition, we also identified DOM compounds using Fourier Transform Ion Cyclotron Mass Spectrometry (FTICRMS). N2 fixation rates were low (average 0.63 ± 0.07 nmol N L−1 d−1), but consistently detected across all depths and stations, representing ~ 6–88 % of photic N2 fixation. N2 fixation rates were not significantly correlated to DOM compounds. The analysis of nifH gene amplicons revealed a wide diversity of non-cyanobacterial diazotrophs, majorly matching clusters 1 and 3. Interestingly, a distinct phylotype from the major nifH subcluster 1G dominated at 650 dbar, coinciding with the oxygenated Sub-Antarctic Mode Water (SAMW). This consistent pattern suggests that the distribution of aphotic diazotroph communities is to some extent controlled by water mass structure. While the data available is still too scarce to elucidate the distribution and controls of mesopelagic non-cyanobacterial diazotrophs in the WTSP, their prevalence in the mesopelagic layer and the consistent detection of active N2 fixation activity at all depths sampled during our study suggest that aphotic N2 fixation may contribute significantly to fixed nitrogen inputs in this area.
Published: 2018

35. Supplementary material to 'Aphotic N2 fixation along an oligotrophic to ultraoligotrophic transect in the Western Tropical South Pacific Ocean'

Author: Mar Benavides, Katyanne M. Shoemaker, Pia H. Moisander, Jutta Niggemann, Thorsten Dittmar, Solange Duhamel, Olivier Grosso, Mireille Pujo-Pay, Sandra Hélias-Nunige, and Sophie Bonnet
Published: 2018

36. A comparison between water circulation and terrestrially-driven dissolved silica fluxes to the Mediterranean Sea traced using radium isotopes

Author: Christophe Monnin, Marc Souhaut, Pieter van Beek, Christelle Claude, Simon Bejannin, Thomas Stieglitz, Mireille Pujo-Pay, Pierre Anschutz, Jordi Garcia-Orellana, Céline Charbonnier, Olivier Crispi, Aladin Andrisoa, Joseph Tamborski, Pascal Conan, Valentí Rodellas, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona [Barcelona] (UAB), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Laboratoire d'Océanographie Microbienne (LOMIC), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Environnement Toulouse (GET), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre for Tropical Water Research & Aquatic Ecosystem Research (TropWATER), James Cook University, Vrije Universiteit [Brussels] (VUB), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), James Cook University (JCU), Vrije Universiteit Brussel (VUB), ANR-MED-SGD [ANR-15-CE01-0004], FEDER, Region Occitanie Pyrenees-Mediterranee (SELECT project), ANR-MED-SGD, Generalitat de Catalunya [2018 SGR-1588], MinECo [MDM2015-0552], RAction of the French Agence National de Recherche ANR [ANR-14-ACHN-0007-01], Labex OT-Med - 'Investissements d'Avenir' program through the AMIDEX project [ANR-11-LABEX-0061, ANR-11-IDEX-0001-02], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Subjects: Submarine groundwater discharge, 010504 meteorology & atmospheric sciences, Dissolved silica, Radium isotopes, 010501 environmental sciences, 01 natural sciences, Mediterranean sea, Geochemistry and Petrology, Mediterranean Sea, 14. Life underwater, Transect, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Pore water exchange, Sediment, 6. Clean water, Circulation, Oceanography, 13. Climate action, Environmental science, Seawater, Surface water, Groundwater
Abstract: International audience; The circulation of seawater through permeable coastal sediments is increasingly recognized as an important source of nutrients, including dissolved silica (DSi), to the coastal ocean. Here, we utilized a Ra isotope (223 Ra, 224 Ra ex , 228 Ra) mass balance to quantify DSi fluxes driven by water circulation to a small shallow coastal lagoon (La Palme; French Mediter-ranean) during June 2016, as compared to karstic groundwater spring inputs. The DSi flux driven by lagoon water circulation (derived from 224 Ra ex) was approximately one order of magnitude greater (1900 ± 1700 mol d À1) than the DSi load of the karstic groundwater spring (250 ± 50 mol d À1) and greater than molecular diffusion (970 ± 750 mol d À1). Lagoon water circulation was a negligible source of 228 Ra, indicating that circulation-driven DSi inputs occur over a timescale of days. Offshore transects were studied to quantify fluxes of marine-derived submarine groundwater discharge (SGD) from the permeable sandy coastline adjacent to the lagoon, into the Mediterranean Sea. Surface water transects revealed near-shore enrichments of Ra and DSi, attributed to wave-setup and water exchange through the permeable beach between the lagoon and the sea. Upscaling over the 9.5 km stretch of sandy beaches results in a marine SGD-driven DSi flux of 2.3 ± 1.3 Â 10 4 mol d À1 , similar in magnitude to the Têt river during November 2016 (3.3 ± 2.4 Â 10 4 mol d À1), the largest river in the region. A positive relationship between DSi and 224 Ra ex in lagoon water and seawater, but not 228 Ra, suggests that 224 Ra ex and DSi enrichments are derived from a similar source, the sediment (i.e. lithogenic particle dissolution), operating on short timescales. A marine SGD-driven DSi flux to the Gulf of Lions (3.8 ± 2.2 Â 10 5 mol d À1) is likely continuous over time. The relatively constant DSi inputs from water circulation for the shallow lagoons and beaches along the French Mediterranean Sea
Published: 2018

37. Nutrient availability and the ultimate control of the biological carbon pump in the western tropical South Pacific Ocean

Author: Thierry Moutin, Thibaut Wagener, Mathieu Caffin, Alain Fumenia, Audrey Gimenez, Melika Baklouti, Pascale Bouruet-Aubertot, Mireille Pujo-Pay, Karine Leblanc, Dominique Lefevre, Sandra Helias Nunige, Nathalie Leblond, Olivier Grosso, Alain de Verneil, 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), Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), LEFE-CYBER program (CNRS-INSU), CNES (BC T23, ZBC 4500048836), European FEDER fund project 1166-39417, ANR-14-CE01-0007,OUTPACE,Sequestration océanique du CO2 et fixation d'azote atmosphérique dans l'océan oligotrophe (campagne océanographique OUTPACE).(2014), Institut méditerranéen d'océanologie ( MIO ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Toulon ( UTLN ) -Aix Marseille Université ( AMU ) -Institut de Recherche pour le Développement ( IRD ), Processus et interactions de fine échelle océanique ( PROTEO ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Océanographie Microbienne ( LOMIC ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'océanographie de Villefranche ( LOV ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), ANR-14-CE01-0007,OUTPACE,Sequestration océanique du CO2 et fixation d’azote atmosphérique dans l'océan oligotrophe (campagne océanographique OUTPACE). ( 2014 ), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, 13. Climate action, 010604 marine biology & hydrobiology, 14. Life underwater, 01 natural sciences, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences
Abstract: Surface waters (0–200 m) of the western tropical South Pacific (WTSP) were sampled along a longitudinal 4000 km transect (OUTPACE cruise, DOI: 10.17600/15000900) during the austral summer (stratified) period (18 February to 3 April 2015) between the Melanesian Archipelago (MA) and the western part of the SP gyre (WGY). Two distinct areas were considered for the MA, the western MA (WMA), and the eastern MA (EMA). The main carbon (C), nitrogen (N), and phosphorus (P) pools and fluxes provide a basis for the characterization of the expected trend from oligotrophy to ultra-oligotrophy, and the building of first-order budgets at the daily and seasonal timescales (using climatology). Sea surface chlorophyll a well reflected the expected oligotrophic gradient with higher values obtained at WMA, lower values at WGY, and intermediate values at EMA. As expected, the euphotic zone depth, the deep chlorophyll maximum, and nitracline depth deepen from west to east. Nevertheless, phosphaclines and nitraclines did not match. The decoupling between phosphacline and nitracline depths in the MA allows for excess P to be locally provided in the upper water by winter mixing. We found a significant biological “soft tissue” carbon pump in the MA sustained almost exclusively by dinitrogen (N2) fixation and essentially controlled by phosphate availability in this iron-rich environment. The MA appears to be a net sink for atmospheric CO2, while the WGY is in quasi-steady state. We suggest that the necessary excess P, allowing the success of nitrogen fixers and subsequent carbon production and export, is mainly brought to the upper surface by local deep winter convection at an annual timescale rather than by surface circulation. While the origin of the decoupling between phosphacline and nitracline remains uncertain, the direct link between local P upper water enrichment, N2 fixation, and organic carbon production and export, offers a possible shorter timescale than previously thought between N input by N2 fixation and carbon export. The low iron availability in the SP gyre and P availability in the MA during the stratified period may appear as the ultimate control of N input by N2 fixation. Because of the huge volume of water to consider, and because the SP Ocean is the place of intense denitrification in the east (N sink) and N2 fixation in the west (N source), precise seasonal C, N, P, and iron (Fe) budgets would be of prime interest to understand the efficiency, at the present time and in the future, of the oceanic biological carbon pump.
Published: 2018

38. Preface to the Special Section: Dense Water Formations in the Northwestern Mediterranean: From the Physical Forcings to the Biogeochemical Consequences

Author: Pierre Testor, Xavier Durrieu de Madron, Claude Estournel, Fabrizio D'Ortenzio, Pascal Conan, Mireille Pujo-Pay, Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Observatoire océanologique de Villefranche-sur-mer (OOVM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Convection, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Ocean current, Biogeochemistry, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Plankton, Oceanography, 01 natural sciences, Atmosphere, Geophysics, Mediterranean sea, Eddy, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Environmental science, 14. Life underwater, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences
Abstract: International audience; The northwestern Mediterranean Sea is one of the few sites of open-sea deep convection and dense water formation. The area is characterized by intense air-sea exchanges favored by the succession of strong northerly and northwesterly winds during autumn and winter that eventually induce deep convection episodes and the formation of the Western Mediterranean Deep Water. This region exhibits a significant spring phytoplankton bloom, which appears to be largely influenced in intensity and diversity by the winter mixing. To understand and resolve the interplay between the atmosphere and ocean, and the impact of ocean circulation and mixing on biogeochemistry, we carried out an unprecedented observational ffort during a large experiment between July 2012 and July 2013. A multiplatform approach—combining aircraft, balloons, ships, moorings,floats, and gliders - aimed both at characterizing the dynamics of the atmosphere and at quantifying the physical, biogeochemical, and biological properties of the water masses.Beyond a better understanding of the wind dynamics, the interannual variability of the deep convection, and the seasonal variability of the nutrient distribution and plankton structure in the pelagic ecosystem, the experiment provided a reference data set that was used as a benchmark for advancing the modeling of the surface fluxes, convective processes, dense water formation rates, and physical-biogeochemical coupling processes. It also represented an opportunity for complementary investigations such as evaluating model parameterizations or studying the role of submesoscale eddies in dense water spreading and biogeochemistry.
Published: 2018

39. Nitrogen and Phosphorus Budgets in the Northwestern Mediterranean Deep Convection Region

Author: Vincent Taillandier, Fabrizio D'Ortenzio, Fayçal Kessouri, Orens Pasqueron de Fommervault, Caroline Ulses, Mireille Pujo-Pay, Tatiana Severin, Pascal Conan, Patrick Raimbault, Pierre Testor, Jocelyne Caparros, Patrick Marsaleix, Claude Estournel, Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Marine Science Institute [Port Aransas], University of Texas at Austin [Austin], Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), European Project: 287600,EC:FP7:ENV,FP7-OCEAN-2011,PERSEUS(2012), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Laboratoire d'océanographie biologique de Banyuls (LOBB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Observatoire océanologique de Banyuls (OOB)
Subjects: 0106 biological sciences, Mediterranean climate, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Spring bloom, Oceanography, Annual cycle, 01 natural sciences, Geophysics, Mediterranean sea, Water column, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], Phytoplankton, Earth and Planetary Sciences (miscellaneous), Environmental science, Photic zone, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: The aim of this study is to understand the biogeochemical cycles of the northwestern Mediterranean Sea (NW Med), where a recurrent spring bloom related to dense water formation occurs. We used a coupled physical-biogeochemical model at high resolution to simulate realistic one-year period and analyze the nitrogen (N) and phosphorus (P) cycles. First, the model was evaluated using cruises carried out in winter, spring and summer and a Bio-Argo float deployed in spring. Then, the annual cycle of meteorological and hydrodynamical forcing and nutrients stocks in the upper layer were analyzed. Third, the effect of biogeochemical and physical processes on N and P was quantified. Fourth, we quantified the effects of the physical and biological processes on the seasonal changes of the molar NO3:PO4 ratio, particularly high compared to the global ocean. The deep convection reduced the NO3:PO4 ratio of upper waters, but consumption by phytoplankton increased it. Finally, N and P budgets were estimated. At the annual scale, this area constituted a sink of inorganic and a source of organic N and P for the peripheral area. NO3 and PO4 were horizontally advected from the peripheral regions into the intermediate waters (130-800 m) of the deep convection area, while organic matter was exported throughout the whole water column toward the surrounding areas. The annual budget suggests that the NW Med deep convection constitutes a major source of nutrients for the photic zone of the Mediterranean Sea.
Published: 2017

40. Influence of PAHs among other coastal environmental variables on total and PAH-degrading bacterial communities

Author: Pascal Conan, Catherine Guigue, Madeleine Goutx, Caroline Sauret, Jean-François Ghiglione, Marc Tedetti, Chloé Dumas, Raphaël Lami, Mireille Pujo-Pay, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0301 basic medicine, Mediterranean climate, Biogeochemical cycle, [SDE.MCG]Environmental Sciences/Global Changes, Health, Toxicology and Mutagenesis, MPN, Microbial Consortia, Wastewater, 010501 environmental sciences, 01 natural sciences, Sea surface microlayer, Marine microbial ecotoxicology, 03 medical and health sciences, RNA, Ribosomal, 16S, Mediterranean Sea, Environmental Chemistry, Seawater, 14. Life underwater, Polycyclic Aromatic Hydrocarbons, CE-SSCP, Transect, Effluent, Phylogeny, 0105 earth and related environmental sciences, Sea surface, microlayer, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Shore, geography, geography.geographical_feature_category, Community structure, PAH, General Medicine, [SDE.ES]Environmental Sciences/Environmental and Society, Pollution, 6. Clean water, qPCR, 030104 developmental biology, Solubility, 13. Climate action, Environmental chemistry, Environmental science, Seasons, Water Pollutants, Chemical, Environmental Monitoring
Abstract: We evaluated the relative impact of anthropogenic polycyclic aromatic hydrocarbons (PAHs) among biogeochemical variables on total, metabolically active, and PAH bacterial communities in summer and winter in surface microlayer (SML) and subsurface seawaters (SSW) across short transects along the NW Mediterranean coast from three harbors, one wastewater effluent, and one nearshore observatory reference site. At both seasons, significant correlations were found between dissolved total PAH concentrations and PAH-degrading bacteria that formed a gradient from the shore to nearshore waters. Accumulation of PAH degraders was particularly high in the SML, where PAHs accumulated. Harbors and wastewater outfalls influenced drastically and in a different way the total and active bacterial community structure, but they only impacted the communities from the nearshore zone (
Published: 2015

41. Top-Down Control of Diesel-Degrading Prokaryotic Communities

Author: Agathe Talarmin, Caroline Sauret, Catherine Guigue, Jean-François Ghiglione, Pascal Conan, Daniela Böttjer, and Mireille Pujo-Pay
Subjects: Microbial food web, Bacteria, Ecology, biology, Microbial Consortia, Soil Science, Roseobacter, biology.organism_classification, Mesocosm, Biostimulation, Biodegradation, Environmental, Petroleum, Bioremediation, Microbial ecology, Seawater, Phaeobacter, Water Microbiology, Ecosystem, Ecology, Evolution, Behavior and Systematics
Abstract: Biostimulation through the addition of inorganic nutrients has been the most widely practiced bioremediation strategy in oil-polluted marine waters. However, little attention has so far been paid to the microbial food web and the impact of top-down control that directly or indirectly influences the success of the bioremediation. We designed a mesocosm experiment using pre-filtered (
Published: 2015

42. Impact of open-ocean convection on nutrients, phytoplankton biomass and activity

Author: Jocelyne Caparros, Jean-François Ghiglione, X. Durrieu de Madron, Louise Oriol, Matthew J. Oliver, Mireille Pujo-Pay, Loïc Houpert, Pascal Conan, Tatiana Severin, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), School of Marine Science and Policy, University of Delaware [Newark], Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Convection, 010504 meteorology & atmospheric sciences, Phytoplankton bloom, Aquatic Science, Oceanography, 01 natural sciences, Algal bloom, Nutrient budgets, chemistry.chemical_compound, Mediterranean sea, Nutrient, Nitrate, 14. Life underwater, Northwestern Mediterranean Sea, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, 010604 marine biology & hydrobiology, Pelagic zone, Remote sensing, Spring bloom, Open-ocean convection, 6. Clean water, Silicate, chemistry, 13. Climate action, Nutrient stoichiometry, Environmental science
Abstract: International audience; We describe the impact of an open-ocean convection event on nutrient budgets, carbon budget, elemental stoichiometry, phytoplankton biomass and activity in the Northwestern Mediterranean Sea (NWM). In the convective episode examined here we estimated an input of nutrients to the surface layer of 7.0, 8.0 and 0.4×108 mol of silicate, nitrate and phosphate, respectively. These quantities correspond to the annual nutrient input by river discharges and atmospheric depositions in the Gulf of Lion. Such nutrient input is sufficient to sustain new primary production from 46 to 63 g C m−2 y−1, which is the same order of magnitude found in the NWM open waters. Our results together with satellite data analysis, propose new scenarios that explain the origin of the spring phytoplankton bloom occurring in NWM.
Published: 2014

43. Dynamics of particulate organic matter composition in coastal systems: a spatio-temporal study at multi-systems scale

Author: Francois Dindinaud, Michel Lafont, Aurore Gueux, Benoit Lebreton, Christophe Boinet, Vincent Cornille, Gaël Guillou, Jocelyne Caparros, Martine Bréret, Jean-Paul Lehodey, Julien Guillaudeau, Pierre Richard, Fabien Aubert, Sabrina Bichon, Stéphane L'Helguen, Fabrice Garcia, Eric Maria, Laurence Costes, Yolanda Del Amo, Eric Macé, Nicolas Lachaussée, Sandrine Geslin, Pascal Riera, Gauthier Schaal, Elsa Breton, Emilie Grossteffan, Valérie David, Laure Mousseau, Emmanuelle Sultan, Pierre-Guy Sauriau, Karine Grangeré, Nicolas Savoye, Maïa Durozier, Nicole Garcia, Line Bourasseau, Eric Lecuyer, Olivier Crispi, Pascal Claquin, Michel Fornier, David Lemeille, Yann Bozec, Philippe Kerhervé, Franck Petit, Mireille Pujo-Pay, Cédric Leroux, Anne-Marie Corre, Marie Czamanski, Antoine Nowaczyk, Jérémy Devesa, Karine Charlier, Jézabel Lamoureux, Orianne Joly, Hervé Derriennic, Sébastien Aubin, Thierry Cariou, Peggy Rimelin-Maury, Vincent Hanquiez, Sébastien Lefebvre, Camilla Liénart, Patrick Raimbault, Eric Feunteun, Philippe Pineau, Sophie Ferreira, Muriel Crouvoisier, Pascal Conan, Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), CHImie Marine (CHIM), Adaptation et diversité en milieu marin (ADMM), Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Université du Littoral Côte d'Opale (ULCO), Laboratoire d'Océanographie Microbienne (LOMIC), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre De Recherche et d'Enseignement sur les Systèmes Côtiers (CRESCO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Station marine Dinard, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), 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), 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), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), 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), Ecogéochimie et Fonctionnement des Ecosystèmes Benthiques (EFEB), Muséum national d'Histoire naturelle (MNHN), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche de Roscoff (FR2424), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire Européen de la Mer (IUEM), 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), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de recherches en environnement côtier (CREC), Normandie Université (NU)-Normandie Université (NU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Adaptation et diversité en milieu marin (AD2M), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université de Caen Normandie (UNICAEN), Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-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)-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), 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), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut de Recherche pour le Développement (IRD), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Lille-Université du Littoral Côte d'Opale-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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Centre de recherche et d'enseignement des systèmes côtiers (CRESCO), Harte Research Institute for Gulf of Mexico Studies, Texas A&M University [Corpus Christi], Institut de Recherche pour le Développement (IRD)-Institut Universitaire Européen de la Mer (IUEM), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), ESEO-GSII (GSII), ESEO-Tech, Université Bretagne Loire (UBL)-Université Bretagne Loire (UBL), CNRS 5320, Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Nutrition et Neurobiologie intégrée (NutriNeur0), Ecole nationale supérieure de chimie, biologie et physique-Institut Polytechnique de Bordeaux-Université Sciences et Technologies - Bordeaux 1-Institut National de la Recherche Agronomique (INRA)-Université Bordeaux Segalen - Bordeaux 2, Observatoire Volcanologique et Sismologique de Guadeloupe (OVSG), Institut de Physique du Globe de Paris, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université de Brest (UBO), EMBIO, Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), UMS 3113, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO), Biologie des écosystèmes aquatiques (UR BELY), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Normandie Université (NU), Centre Émile Durkheim (CED), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - 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)-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 Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO), Biologie des Organismes et Ecosystèmes Aquatiques ( BOREA ), Université des Antilles ( UA ) -Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Institut de Recherche pour le Développement ( IRD ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Environnements et Paléoenvironnements OCéaniques ( EPOC ), Observatoire aquitain des sciences de l'univers ( OASU ), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -École pratique des hautes études ( EPHE ) -Centre National de la Recherche Scientifique ( CNRS ), CHImie Marine ( CHIM ), Adaptation et diversité en milieu marin ( ADMM ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 ( LOG ), Université du Littoral Côte d'Opale-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Océanographie Microbienne ( LOMIC ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -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 ), Centre de recherche et d'enseignement des systèmes côtiers ( CRESCO ), Muséum National d'Histoire Naturelle ( MNHN ), Centre de Formation et de Recherche sur les Environnements Méditérranéens ( CEFREM ), Université de Perpignan Via Domitia ( UPVD ) -Centre National de la Recherche Scientifique ( CNRS ), Harte Research Institute for Gulf of Mexico Studies, Texas A&M University – Corpus Christi, Rongeurs Sauvages – Risques Sanitaires et Gestion des Populations, INRA, VetAgro Sup ( USC1233/RS2GP ), Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Laboratoire des Sciences de l'Environnement Marin (LEMAR) ( LEMAR ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Brest ( UBO ) -Institut Français de Recherche pour l'Exploitation de la Mer ( IFREMER ) -Institut Universitaire Européen de la Mer ( IUEM ), Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ), Laboratoire d'océanographie de Villefranche ( LOV ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institut méditerranéen d'océanologie ( MIO ), Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Ecogéochimie et Fonctionnement des Ecosystèmes Benthiques ( EFEB ), ESEO-GSII ( GSII ), PRES Université Nantes Angers Le Mans ( UNAM ) -PRES Université Nantes Angers Le Mans ( UNAM ), Centre de recherche Paul Pascal, CNRS, Université de Bordeaux ( UPR8641 ), Centre de Recherche Paul Pascal, CNRS, Université de Bordeaux, Centre National de la Recherche Scientifique ( CNRS ), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux ( EPOC ), Station biologique de Roscoff [Roscoff] ( SBR ), Nutrition et Neurobiologie intégrée ( NutriNeur0 ), Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique ( INRA ) -Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Ecole nationale supérieure de chimie, biologie et physique, OVSG-IPGP, Observatoire Volcanologique et sismologique de la Soufrière de Guadeloupe, Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Université de Brest ( UBO ), Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Universitaire Européen de la Mer ( IUEM ), Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherches en environnement côtier ( CREC ), Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU ), Biologie des écosystèmes aquatiques ( UR BELY ), CEMAGREF, Normandie Université ( NU ), Centre Émile Durkheim ( CED ), and Université de Bordeaux ( UB ) -Sciences Po-Centre National de la Recherche Scientifique ( CNRS )
Subjects: 0106 biological sciences, Mediterranean climate, 010504 meteorology & atmospheric sciences, chibido, Mixing model, Aquatic Science, 01 natural sciences, coastal systems, N ratio [C], C:N ratio, Water column, Particulate organic matter, Phytoplankton, Littoral zone, medicine, Coastal systems, Organic matter, 14. Life underwater, particulate organic matter, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, chemistry.chemical_classification, [ SDE.BE ] Environmental Sciences/Biodiversity and Ecology, geography, geography.geographical_feature_category, C and N stable isotopes, 010604 marine biology & hydrobiology, ACL, Geology, Estuary, Seasonality, mixing model, medicine.disease, meta-analysis, Oceanography, chemistry, 13. Climate action, Benthic zone, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, france
Abstract: International audience; In coastal systems, the multiplicity of sources fueling the pool of particulate organic matter (POM) leads to divergent estimations of POM composition. Eleven systems (two littoral systems, eight embayments and semi-enclosed systems and one estuary) distributed along the three maritime façades of France were studied for two to eight years in order to quantify the relative contribution of organic matter sources to the surface-water POM pool in coastal systems. This study was based on carbon and nitrogen elemental and isotopic ratios, used for running mixing models. The POM of the estuary is dominated by terrestrial material (93% on average), whereas the POM of the other systems is dominated by phytoplankton (84% on average). Nevertheless, for the latter systems, the POM composition varies in space, with 1) systems where POM is highly composed of phytoplankton (≥ 93%), 2) systems characterized by a non-negligible contribution of benthic (8 to 19%) and/or riverine (7 to 19%) sources, and 3) the Mediterranean systems characterized by the contribution of diazotroph organisms (ca. 14%). A continent-to-ocean gradient of riverine and/or benthic POM contribution is observed. Finally, time series reveal 1) seasonal variations of POM composition, 2) differences in seasonality between systems, and 3) an inshore-offshore gradient of seasonality within each system that were sampled at several stations. Spatial and seasonal patterns of POM composition are mainly due to local to regional processes such as hydrodynamics and sedimentary hydrodynamic (e.g. resuspension processes, changes in river flows, wind patterns influencing along-shore currents) but also due to the geomorphology of the systems (depth of the water column, distance to the shore). Future studies investigating the link between these forcings and POM composition would help to better understand the dynamics of POM composition in coastal systems.
Published: 2017

44. Evidence of niche partitioning among bacteria living on plastics, organic particles and surrounding seawaters

Author: Pascale Fabre, Amanda Elineau, Gabriel Gorsky, Jean-François Ghiglione, Pascal Conan, Mireille Pujo-Pay, Claire Dussud, M.L. Pedrotti, J. Coudane, Anne-Leila Meistertzheim, Perry Higgs, Matthieu George, Laboratoire Charles Coulomb (L2C), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0301 basic medicine, Biofouling, Health, Toxicology and Mutagenesis, Plastisphere, Biodiversity, 010501 environmental sciences, Biology, Toxicology, 01 natural sciences, 03 medical and health sciences, Marine debris, Marine ecosystem, Ecosystem, Seawater, 14. Life underwater, 0105 earth and related environmental sciences, Waste Products, Bacteria, Ecology, Niche differentiation, General Medicine, Pollution, 030104 developmental biology, 13. Climate action, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Species evenness, Microbial ecotoxicology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Plastic pollution, Plastics, Environmental Monitoring
Abstract: Plastic pollution is widespread in ocean ecosystems worldwide, but it is unknown if plastic offers a unique habitat for bacteria compared to communities in the water column and attached to naturally-occurring organic particles. The large set of samples taken during the Tara-Mediterranean expedition revealed for the first time a clear niche partitioning between free-living (FL), organic particle-attached (PA) and the recently introduced plastic marine debris (PMD). Bacterial counts in PMD presented higher cell enrichment factors than generally observed for PA fraction, when compared to FL bacteria in the surrounding waters. Taxonomic diversity was also higher in the PMD communities, where higher evenness indicated a favorable environment for a very large number of species. Cyanobacteria were particularly overrepresented in PMD, together with essential functions for biofilm formation and maturation. The community distinction between the three habitats was consistent across the large-scale sampling in the Western Mediterranean basin. 'Plastic specific bacteria' recovered only on the PMD represented half of the OTUs, thus forming a distinct habitat that should be further considered for understanding microbial biodiversity in changing marine ecosystems.
Published: 2017

45. Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Terminos Lagoon, Mexico) under 2009-2010 El Nino Modoki drought conditions

Author: Sandrine Chifflet, Laura G. Calva-Benítez, Arturo Rodríguez-Blanco, Claire Dussud, Montserrat Origel-Moreno, Tatiana Severin, Renaud Fichez, Pascal Conan, Caroline Sauret, Christian Grenz, Jean-François Ghiglione, Mireille Pujo-Pay, Pascal Douillet, Marina Agab, Marc Tedetti, Rocío Torres Alvarado, Francisco José Gutiérrez Mendieta, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad Autónoma Metropolitana [Mexico] (UAM), Universidad Autonoma Metropolitana, Unidad Cuajimalpa, 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), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Microbienne ( LOMIC ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Universidad Autónoma Metropolitana [Mexico] ( UAM ), Universidad Autonoma Metropolitana - Cuajimalpa (UAM), 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, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, [SDV]Life Sciences [q-bio], lcsh:Life, 01 natural sciences, Water column, Nutrient, lcsh:QH540-549.5, Phytoplankton, Dissolved organic carbon, Organic matter, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, chemistry.chemical_classification, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, [ SDV ] Life Sciences [q-bio], 010604 marine biology & hydrobiology, lcsh:QE1-996.5, Estuary, Bacterioplankton, 15. Life on land, 6. Clean water, lcsh:Geology, lcsh:QH501-531, Oceanography, chemistry, 13. Climate action, Environmental science, lcsh:Ecology
Abstract: The 2009–2010 period was marked by an episode of intense drought known as the El Niño Modoki event. Sampling of the Términos Lagoon (Mexico) was carried out in November 2009 in order to understand the influence of these particular environmental conditions on organic matter fluxes within the lagoon's pelagic ecosystem and, more specifically, on the relationship between phyto- and bacterioplankton communities. The measurements presented here concern biogeochemical parameters (nutrients, dissolved and particulate organic matter [POM], and dissolved polycyclic aromatic hydrocarbons [PAHs]), phytoplankton (biomass and photosynthesis), and bacteria (diversity and abundance, including PAH degradation bacteria and ectoenzymatic activities). During the studied period, the water column of the Términos Lagoon functioned globally as a sink and, more precisely, as a nitrogen assimilator. This was due to the high production of particulate and dissolved organic matter (DOM), even though exportation of autochthonous matter to the Gulf of Mexico was weak. We found that bottom-up control accounted for a large portion of the variability of phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and free-living prokaryote distribution in the lagoon. In the eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen near the Puerto Real coastal inlet and areas enriched in phosphate (PO4) near the Candelaria estuary. Such a decoupling limited the potential for primary production, resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) near the river mouths. In the western part of the lagoon, maximal phytoplankton development resulted from bacterial activity transforming particulate organic phosphorus (PP) and dissolved organic phosphorus (DOP) to available PO4 and the coupling between Palizada River inputs of nitrate (NO3) and PP. The Chumpan River contributed only marginally to PO4 inputs due to its very low contribution to overall river inputs. The highest dissolved total PAH concentrations were measured in the El Carmen Inlet, suggesting that the anthropogenic pollution of the zone is probably related to the oil-platform exploitation activities in the shallow waters of the southern of the Gulf of Mexico. We also found that a complex array of biogeochemical and phytoplanktonic parameters were the driving force behind the geographical distribution of bacterial community structure and activities. Finally, we showed that nutrients brought by the Palizada River supported an abundant bacterial community of PAH degraders, which are of significance in this important oil-production zone.
Published: 2017

46. Plastic Litter: A New Habitat for Marine Microbial Communities

Author: Matthieu George, O. Crispi, Pascale Fabre, S. Petit, C. Dussud, A. Elineau, Jean-François Ghiglione, Pascal Conan, Mireille Pujo-Pay, G. Gorsky, and M.-L. Pedrotti
Subjects: 010504 meteorology & atmospheric sciences, Habitat, Ecology, Litter, Environmental science, 010501 environmental sciences, 01 natural sciences, 0105 earth and related environmental sciences
Published: 2017

47. Impact of an intense water column mixing (0-1500 m) on prokaryotic diversity and activities during an open-ocean convection event in the NW Mediterranean Sea

Author: Tatiana, Severin, Caroline, Sauret, Mehdi, Boutrif, Thomas, Duhaut, Fayçal, Kessouri, Louise, Oriol, Jocelyne, Caparros, Mireille, Pujo-Pay, Xavier, Durrieu de Madron, Marc, Garel, Christian, Tamburini, Pascal, Conan, and Jean-François, Ghiglione
Subjects: Bacteria, Mediterranean Sea, Heterotrophic Processes, Seawater, Biodiversity, Seasons
Abstract: Open-ocean convection is a fundamental process for thermohaline circulation and biogeochemical cycles that causes spectacular mixing of the water column. Here, we tested how much the depth-stratified prokaryotic communities were influenced by such an event, and also by the following re-stratification. The deep convection event (0-1500 m) that occurred in winter 2010-2011 in the NW Mediterranean Sea resulted in a homogenization of the prokaryotic communities over the entire convective cell, resulting in the predominance of typical surface Bacteria, such as Oceanospirillale and Flavobacteriales. Statistical analysis together with numerical simulation of vertical homogenization evidenced that physical turbulence only was not enough to explain the new distribution of the communities, but acted in synergy with other parameters such as exported particulate and dissolved organic matters. The convection also stimulated prokaryotic abundance (+21%) and heterotrophic production (+43%) over the 0-1500 m convective cell, and resulted in a decline of cell-specific extracellular enzymatic activities (-67%), thus suggesting an intensification of the labile organic matter turnover during the event. The rapid re-stratification of the prokaryotic diversity and activities in the intermediate layer 5 days after the intense mixing indicated a marked resilience of the communities, apart from the residual deep mixed water patch.
Published: 2016

48. Nutrient control of N2 fixation in the oligotrophic Mediterranean Sea and the impact of Saharan dust events

Author: M. Le Moal, Cécile Guieu, Céline Ridame, Mireille Pujo-Pay, Stéphane L'Helguen, E. Ternon, and Isabelle C. Biegala
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Mixed layer, 010604 marine biology & hydrobiology, chemistry.chemical_element, Mineral dust, Structural basin, Atmospheric sciences, 01 natural sciences, Nitrogen, Oceanography, Nutrient, Mediterranean sea, chemistry, Nitrogen fixation, Environmental science, Spatial variability, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: A better understanding of the factors controlling N2 fixation is a pre-requisite for improving our knowledge on the contribution of N2 fixation process in the nitrogen cycling. Trace-metal clean nutrient/dust addition bioassays (+P, +PFe, +dust) were performed at three stations located in the western, central and eastern Mediterranean Sea, in summer 2008 as part of the BOUM cruise. The main goals were (1) to investigate the nutrient factor(s) limiting N2 fixation (uptake of 15N2) and (2) to evaluate the potential impact of a Saharan dust event on this biological process during the stratification period. Initially, surface waters at the three stations were DIP-depleted (
Published: 2011

49. Impact of phytoplankton and bacterial production on nutrient and DOM uptake in the Rhône River plume (NW Mediterranean)

Author: Jean Jacques Naudin, Fabien Joux, Pascal Conan, Gustave Cauwet, Mireille Pujo-Pay, and Louise Oriol
Subjects: Mediterranean climate, geography, geography.geographical_feature_category, Ecology, fungi, Estuary, Aquatic Science, Algal bloom, Salinity, Oceanography, Nutrient, Dissolved organic carbon, Phytoplankton, Environmental science, Dominance (ecology), Ecology, Evolution, Behavior and Systematics
Abstract: From April 1998 to April 1999, 4 cruises were conducted to investigate the evolution of physical and biological characteristics of the Rhone River plume. Particular emphasis was placed on the relationships between phytoplanktonic or bacterial production and environmental conditions. For most of the year, distributions of nutrients, phytoplankton and bacterial activities were conservative along the salinity gradient, indicating the dominance of physical dilution processes. In April 1999, nutrient-salinity relationships showed strong deviations from the conservative mixing line which were associated with a phytoplankton bloom. Deviations from the conservative mixing line were used to estimate the relative contributions of physical and biological processes in the removal of riverine derived material. During the phytoplankton bloom, there was a specific organisation of the microbial populations and their activities at intermediate salinity. Maximal productions were associ- ated with maxima in ammonium and phosphate uptake rates for bacteria, but with maxima in nitrate uptake rates for phytoplankton. The relative accumulation of dissolved organic carbon (DOC) and nitrogen (DON) at high salinity, and the seasonal variability in their distribution, resulted in a poten- tial competition between bacteria and phytoplankton for key mineral nutrients highlighted by an increase in the DOC:DON ratio up to 10. This study contributes to our understanding of the relation- ship between phytoplankton, bacteria and dissolved organic matter and helps to elucidate the factors controlling the productivity of the system. In particular, the impact of wind and riverine output need to be considered alongside seasonal variability in the chemical and hydrodynamic environment.
Published: 2006

50. A direct instrument comparison for measurement of total dissolved nitrogen in seawater

Author: G. Spyres, O. Primm, Mireille Pujo-Pay, Gustave Cauwet, K. Nagel, Alexander E. Parker, A.Y. Beauregard, S.E. Curless, Sybil P. Seitzinger, Renee M. Styles, David J. Burdige, Hiroshi Ogawa, R. Lauck, Jonathan H. Sharp, and W.B. Savidge
Subjects: Total organic carbon, Instrumentation, chemistry.chemical_element, General Chemistry, Oceanography, Persulfate, Combustion, Nitrogen, chemistry, Environmental chemistry, Dissolved organic carbon, Environmental Chemistry, Seawater, Dissolved nitrogen, Water Science and Technology
Abstract: A direct comparison has been made for the measurement of total dissolved nitrogen (TDN) in seawater using high temperature combustion (HTC) instruments. A side-by-side comparison in one laboratory (Lewes exercise) was made with two hybrid total organic carbon (TOC) instruments linked to chemiluminescence detectors (CLD), a combined TOC total nitrogen (TN) instrument, and two stand-alone TN instruments. Later, a series of field samples was run in home laboratories of the participants (Homelab exercise) using four hybrid TOC–CLD systems, the combined TOC/TN instrument, and three standalone TN instruments. In the Lewes and Homelab exercises, samples were also run by the more established persulfate oxidation method. There was fairly good agreement (group precision) among all the HTC methods; average %CV of F12.0% for five nitrogen compounds and average %CVof F7.7% for five natural samples in the Lewes exercise and %CVof F10.7% for 14 field samples in the Homelab exercise. In both cases, the persulfate method values were similar to those of the HTC instruments. On a finer scale of evaluation, the stand-alone TN instruments, operating at higher combustion temperatures, gave considerably more scatter and more divergent values than the set of HTC instruments that used a singular combustion environment with a lower temperature. The five hybrid systems, with Shimadzu TOC instruments combined with five different CLD systems and employing individual integration programs, gave a group precision of F5.8% for the field samples. These systems also provided simultaneous dissolved organic carbon (DOC) concentrations, and the DOC group precision for the 14 samples was F5.9%. Our conclusion is that the five Shimadzu instrument systems provide more accurate TDN measurements than the stand-alone instruments. However, when subtracting inorganic nitrogen (DIN) to calculate dissolved organic nitrogen (DON), there is not good agreement, especially for deep ocean samples. The persulfate method gave slightly higher TDN concentrations for the field samples than the Shimadzu HTC averages, indicating a possibility of incomplete conversion of some nitrogen compounds by the HTC instruments and/or peak integration problems. The inequity with persulfate oxidation and the scatter with the HTC methods require further investigation. A new broad community DON comparison is currently underway
Published: 2004

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