Consulta: creatorFacets:"Leynaert, Aude"
Registros recuperados: 13
Data/hora: 12/06/2024 14:40:16

New insights into the seasonal feeding ecology of Pecten maximus using pigments, fatty acids and sterols analyses
Provedor de dados: 5
Autores: Lavaud, Romain; Artigaud, Sebastien; Le Grand, Fabienne; Donval, Anne; Soudant, Philippe; Flye-sainte-marie, Jonathan; Strohmeier, Tore; Strand, Oivind; Leynaert, Aude; Beker, Beatriz; Chatterjee, Arnab; Jean, Fred.
We combined the use of pigments, fatty acids and sterols as biomarkers of the seasonal variation in food sources of the great scallop Pecten maximus. From March to October 2011, on a biweekly to twice-weekly basis, scallops and seawater from the water column and the water-sediment interface were collected in the Bay of Brest (Brittany, France). Pigment compositions in the seawater and in the stomach and rectum content of the scallops were analyzed by HPLC. Fatty acids and sterols from digestive gland (DG) tissue were analyzed by gas chromatography. Potential relationships between the temporal proportion of each marker in the environment and in the digestive tract were tested using multivariate analysis. Proportions of diatoms and Dinophyceae biomarkers...
Tipo: Text
Palavras-chave: Trophic ecology; Food sources; Pigments; Fatty acids; Trophic marker; Phytoplankton; Pecten maximus.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00431/54244/55772.pdf

Estimating biogenic silica production of Rhizaria in the global ocean
Provedor de dados: 5
Autores: Llopis Monferrer, Natalia; Boltovskoy, Demetrio; Tréguer, Paul; Mendez Sandin, Miguel; Not, Fabrice; Leynaert, Aude.
Siliceous polycystines and phaeodarians are open‐ocean planktonic protists found throughout the water column and characterized by complex siliceous skeletons that are formed, at least partly, through the uptake of silicic acid. These protists contribute to the marine organic carbon (C) and biogenic silica (bSi) pools but little is known about their contribution to the silica (Si) biogeochemical cycle. Here we report the first measurements of the Si uptake rate of polycystine and phaeodarian cells from samples collected in the Mediterranean Sea using the 32Si based method. The elementary composition (bSi, particulate organic carbon and nitrogen) of these organisms was also measured. Combining our results with published data on the distribution and abundance...
Tipo: Text
Palavras-chave: Silica cycle; Silicic acid uptake; Rhizaria; Polycystina; Phaeodaria; Radiolaria.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00609/72154/70904.pdf

Role of small Rhizaria and diatoms in the pelagic silica production of the Southern Ocean
Provedor de dados: 5
Autores: Llopis Monferrer, Natalia; Leynaert, Aude; Tréguer, Paul; Gutiérrez‐rodríguez, Andrés; Moriceau, Brivaela; Gallinari, Morgane; Latasa, Mikel; L'Helguen, Stéphane; Maguer, Jean-francois; Safi, Karl; Pinkerton, Matthew H.; Not, Fabrice.
We examined biogenic silica production and elementary composition (biogenic Si, particulate organic carbon and particulate organic nitrogen) of Rhizaria and diatoms in the upper 200 m along a transect in the Southwest Pacific sector of the Southern Ocean during austral summer (January–February 2019). From incubations using the 32Si radioisotope, silicic acid uptake rates were measured at 15 stations distributed in the Polar Front Zone, the Southern Antarctic Circumpolar Current and the Ross Sea Gyre. Rhizaria cells are heavily silicified (up to 7.6 nmol Si cell−1), displaying higher biogenic Si content than similar size specimens found in other areas of the global ocean, suggesting a higher degree of silicification of these organisms in the silicic acid...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00692/80407/83515.pdf

In situ determination of Si, N, and P utilization by the demosponge Tethya citrina: A benthicchamber approach
Provedor de dados: 5
Autores: Lopez-acosta, Maria; Leynaert, Aude; Chavaud, Laurent; Amice, Erwan; Bihannic, Isabelle; Le Bec, Thierry; Maldonado, Manuel.
Sponges consume dissolved silicon (DSi) to build their skeletons. Few studies have attempted to quantify DSi utilization by these organisms and all available determinations come from laboratory measurements. Here we measured DSi consumption rates of the sponge Tethya citrina in its natural habitat, conducting 24h incubations in benthic chambers. Sponges consumed DSi at an average rate of 0.046 +/- 0.018 mu mol h(-1) mL(-1) when DSi availability in its habitat was 8.3 +/- 1.8 mu M. Such DSi consumption rates significantly matched the values predicted by a kinetic model elsewhere developed previously for this species through laboratory incubations. These results support the use of laboratory incubations as a suitable approach to learn about DSi consumption....
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00605/71664/70115.pdf

Late spring bloom development of pelagic diatoms in Baffin Bay
Provedor de dados: 5
Autores: Lafond, Augustin; Leblanc, Karine; Queguiner, Bernard; Moriceau, Brivaela; Leynaert, Aude; Cornet, Veronique; Legras, Justine; Ras, Josephine; Parenteau, Marie; Garcia, Nicole; Babin, Marcel; Tremblay, Jean-eric.
The Arctic Ocean is particularly affected by climate change, with changes in sea ice cover expected to impact phytoplankton primary production. During the Green Edge expedition, the development of the late spring-early summer diatom bloom was studied in relation with the sea ice retreat by multiple transects across the marginal ice zone. Biogenic silica concentrations and uptake rates were measured. In addition, diatom assemblage structures and their associated carbon biomass were determined, along with taxon-specific contributions to total biogenic silica production using the fluorescent dye PDMPO. Results indicate that a diatom bloom developed in open waters close to the ice edge, following the alleviation of light limitation, and extended 20-30 km...
Tipo: Text
Palavras-chave: Diatoms; Spring bloom; Sea ice; Community composition; Baffin Bay; Arctic.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00615/72752/72021.pdf

New insights into the reproductive cycle of two Great Scallop populations in Brittany (France) using a DEB modelling approach
Provedor de dados: 5
Autores: Gourault, Melaine; Lavaud, Romain; Leynaert, Aude; Pecquerie, Laure; Paulet, Yves-marie; Pouvreau, Stephane.
The present study aimed to improve understanding of the environmental conditions influencing the reproductive cycle of the great scallop Pecten maximus in two locations in Brittany (France). We also evaluated potential consequences of future climate change for reproductive success in each site. We simulated reproductive traits (spawning occurrences and synchronicity among individuals) of P. maximus, using an existing Dynamic Energy Budget (DEB) model. To validate and test the model, we used biological and environmental datasets available for the Bay of Brest (West Brittany, France) between 1998 and 2003. We also applied the scallop DEB model in the Bay of Saint-Brieuc (North Brittany, France) for the same period (1998–2003) to compare the reproductive...
Tipo: Text
Palavras-chave: Pecten maximus; DEB theory; Reproduction cycle; IPCC scenarios; Bay of Brest; Bay of Saint-Brieuc.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00458/57012/58910.pdf

Dissolved inorganic nitrogen uptake by intertidal microphytobenthos: nutrient concentrations, light availability and migration
Provedor de dados: 5
Autores: Longphuirt, Sorcha Ni; Lim, Jae-hyun; Leynaert, Aude; Claquin, Pascal; Choy, Eun-jung; Kang, Chang Keun; An, Shu.
The importance of intertidal flats as areas of nitrogen filtering has become increasingly apparent in recent times. TO understand fully the cycling of this nutrient. in these areas of high metabolic activity, it is necessary to elucidate the influence of microphytobenthos (MPB) on stocks of ammonium and nitrate in surface areas. In this study, we aimed to quantity nitrogen uptake and relate it to the in Situ concentrations and environmental conditions to which MPB are exposed. In an estuarine system on the Korean Peninsula, we conducted kinetic experiments using N-15 stable isotopes and core sampling over the tidal cycle to determine the temporal evolution of porewater nutrient concentrations and the migration of MPB. The results revealed a range of K-s...
Tipo: Text
Palavras-chave: N 15 stable isotope; Porewater; Microphytobenthos; Kinetic; Nitrogen.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6622.pdf

Silicon utilization by sponges: an assessment of seasonal changes
Provedor de dados: 5
Autores: Lopez-acosta, Maria; Leynaert, Aude; Coquille, Valerie; Maldonado, Manuel.
Awareness that sponges are relevant silicic acid (DSi) users is growing; however, understanding how their DSi consumption kinetics perform is still limited. We investigated the effects that seasonal changes in a temperate ecosystem (Bay of Brest, France) have on the DSi consumption of 2 dominant sponge species: Hymeniacidon perlevis and Tethya citrina. The results indicated that while both species increased their rate of DSi utilization with DSi availability following saturable Michaelis-Menten kinetics, only the kinetics of T. citrina shifted seasonally. This species consumed DSi at a higher rate in autumn than in summer. Surprisingly, the increase in DSi utilization did not involve an increase in net affinity for DSi but rather augmentation of both the...
Tipo: Text
Palavras-chave: Silicic acid; Silicon consumption kinetics; Siliceous sponges; Seasonal variability.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00616/72772/72246.pdf

High alkaline phosphatase activity in phosphate replete waters: The case of two macrotidal estuaries
Provedor de dados: 5
Autores: Labry, Claire; Delmas, Daniel; Youenou, Agnes; Quere, Julien; Leynaert, Aude; Fraisse, Stephane; Raimonet, Melanie; Ragueneau, Olivier.
The occurrence of alkaline phosphatase activity (APA) that hydrolyses organic phosphorus into phosphate (PO4) is commonly related to PO4 deficiency of oceanic, coastal and fresh waters. APA is almost never investigated in PO4-rich estuaries, since very low activities are expected to occur. As a consequence, microbial mineralization of organic phosphorus into PO4 has often been ignored in estuaries. In this study, we examined the importance of potential APA and the associated microbial dynamics in two estuaries, the Aulne and the Elorn (Northwestern France), presenting two different levels of PO4 concentrations. Unexpected high potential APA was observed in both estuaries. Values ranged from 50 to 506 nmol L−1 h−1, which range is usually found in very...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00337/44840/44428.pdf

Linking Spatial and Temporal Dynamic of Bacterioplankton Communities With Ecological Strategies Across a Coastal Frontal Area
Provedor de dados: 5
Autores: Lemonnier, Clarisse; Perennou, Morgan; Eveillard, Damien; Fernandez-guerra, Antonio; Leynaert, Aude; Marié, Louis; Morrison, Hilary G.; Memery, Laurent; Paillard, Christine; Maignien, Lois.
Ocean frontal systems are widespread hydrological features defining the transition zone between distinct water masses. They are generally of high biological importance as they are often associated with locally enhanced primary production by phytoplankton. However, the composition of bacterial communities in the frontal zone remains poorly understood. In this study, we investigate how a coastal tidal front in Brittany (France) structures the free-living bacterioplankton communities in a spatio-temporal survey across four cruises, five stations and three depths. We used 16S rRNA gene surveys to compare bacterial community structures across 134 seawater samples and defined groups of co-varying taxa (modules) exhibiting coherent ecological patterns across...
Tipo: Text
Palavras-chave: Marine front; Bacterial communities; Dynamic; Network; Ecological strategies.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00634/74657/74557.pdf

Phytoplankton phosphorus limitation in a North Atlantic coastal ecosystem not predicted by nutrient load
Provedor de dados: 5
Autores: Trommer, Gabriele; Leynaert, Aude; Klein, Cecile; Naegelen, Aurore; Beker, Beatriz.
Phytoplankton nutrient limitation patterns were investigated in an anthropogenically influenced coastal ecosystem with a high nutrient load. Weekly nutrient limitation bioassays, and water chemistry and stoichiometry measurements were performed in the Bay of Brest, France, from February to July 2011. Each limitation bioassay included phosphorus, nitrogen, silicate and all possible combined nutrient additions, and lasted over 72 h. Results showed that the phytoplankton community experienced a general P limitation from March to July. N limitation alone was observed only during 1 week in early March. Subsequently, all limitation bioassays revealed primary P limitation, indicated by significantly increased growth rates in all samples containing P additions....
Tipo: Text
Palavras-chave: Phytoplankton; Stoichiometry; Bioassays; Nutrient limitation; Coastal ecosystem.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00368/47947/48023.pdf

Green Edge ice camp campaigns: understanding the processes controlling the under-ice Arctic phytoplankton spring bloom
Provedor de dados: 5
Autores: Massicotte, Philippe; Amiraux, Rémi; Amyot, Marie-pier; Archambault, Philippe; Ardyna, Mathieu; Arnaud, Laurent; Artigue, Lise; Aubry, Cyril; Ayotte, Pierre; Bécu, Guislain; Bélanger, Simon; Benner, Ronald; Bittig, Henry C; Bricaud, Annick; Brossier, Eric; Bruyant, Flavienne; Chauvaud, Laurent; Christiansen-stowe, Debra; Claustre, Hervé; Cornet-barthaux, Véronique; Coupel, Pierre; Cox, Christine; Delaforge, Aurélie; Dezutter, Thibault; Dimier, Céline; Dominé, Florent; Dufour, Francis; Dufresne, Christiane; Dumont, Dany; Ehn, Jens; Else, Brent; Ferland, Joannie; Forget, Marie-hélène; Fortier, Louis; Gali, Marti; Galindo, Virginie; Gallinari, Morgane; Garcia, Nicole; Gerikas-ribeiro, Catherine; Gourdal, Margaux; Gourvil, Priscilla; Goyens, Clemence; Grondin, Pierre-luc; Guillot, Pascal; Guilmette, Caroline; Houssais, Marie-noëlle; Joux, Fabien; Lacour, Léo; Lacour, Thomas; Lafond, Augustin; Lagunas, José; Lalande, Catherine; Laliberté, Julien; Lambert-girard, Simon; Larivière, Jade; Lavaud, Johann; Lebaron, Anita; Leblanc, Karine; Le Gall, Florence; Legras, Justine; Lemire, Mélanie; Levasseur, Maurice; Leymarie, Edouard; Leynaert, Aude; Lopes Dos Santos, Adriana; Lourenço, Antonio; Mah, David; Marec, Claudie; Marie, Dominique; Martin, Nicolas; Marty, Constance; Marty, Sabine; Massé, Guillaume; Matsuoka, Atsushi; Matthes, Lisa; Moriceau, Brivaela; Muller, Pierre-emmanuel; Mundy, Christopher-john; Neukermans, Griet; Oziel, Laurent; Panagiotopoulos, Christos; Pangazi, Jean-jacques; Picard, Ghislain; Picheral, Marc; Pinczon Du Sel, France; Pogorzelec, Nicole; Probert, Ian; Queguiner, Bernard; Raimbault, Patrick; Ras, Joséphine; Rehm, Eric; Reimer, Erin; Rontani, Jean-françois; Rysgaard, Soren; Saint-béat, Blanche; Sampei, Makoto; Sansoulet, Julie; Schmidt, Sabine; Sempere, Richard; Sevigny, Caroline; Shen, Yuan; Tragin, Margot; Tremblay, Jean-eric; Vaulot, Daniel; Verin, Gauthier; Vivier, Frédéric; Vladoiu, Anda; Whitehead, Jeremy; Babin, Marcel.
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and the fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797N, 63.7895W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea ice cover from the surface to the bottom at 360 m depth to better understand the factors driving the PSB. Key variables such as temperature, salinity, radiance, irradiance, nutrient concentrations, chlorophyll-a concentration,...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00598/71000/69266.pdf

Reviews and syntheses: The biogeochemical cycle of silicon in the modern ocean
Provedor de dados: 5
Autores: Treguer, Paul; Sutton, Jill; Brzezinski, Mark; Charette, Matthew A.; Devries, Timothy; Dutkiewicz, Stephanie; Ehlert, Claudia; Hawkings, Jon; Leynaert, Aude; Mei Liu, Su; Llopis Monferrer, Natalia; Lopez Acosta, Maria; Maldonado, Manuel; Rahman, Shaily; Ran, Lihua; Rouxel, Olivier.
he element silicon (Si) is required for the growth of silicified organisms in marine environments, such as diatoms, which consume vast amounts of Si together with N, P, and C, connecting the biogeochemical cycles of these elements. Thus, understanding the Si cycle in the ocean is critical for understanding issues such as carbon sequestration by the ocean's biological pump. In this review, we show that recent advances in process studies indicate that total Si inputs and outputs, to and from the world ocean, are 57 % and 18 % higher, respectively, than previous estimates. We also update the total ocean silicic acid inventory value, which is about 24 % higher than previously estimated. These changes are significant, modifying factors such as the geochemical...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00643/75509/76356.pdf