|
|
|
|
| |
|
|
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 |
| |
|
|
L'Helguen, Stéphane; Rimmelin-maury, Peggy; Repecaud, Michel; Quemener, Loic; Beaumont, L.; Grosssteffan, Emilie; Tréguer, Paul; Bozec, Yann. |
Les écosystèmes côtiers sont soumis à de multiples forçages physiques et chimiques qui agissent à des échelles de temps très différentes. Pour décrire et prédire l’impact de ces forçages sur les écosystèmes, il est impératif de mesurer à long terme les caractéristiques physiques, chimiques et biologiques des eaux côtières. Depuis plus de 15 ans, un partenariat réunit l’IUEM/UBO, l’IFREMER et l'INSU pour assurer le suivi régulier et à long terme de la physico-chimie des eaux côtières à l’interface de la rade de Brest et de la mer d’Iroise (site de Ste Anne du Portzic, 48°21’60 N, 4°33’04 W ). Ce suivi repose sur une stratégie combinée de mesures à basse fréquence (série SOMLIT-Brest - Service d’Observation en Milieu LITtoral) et de mesures à haute fréquence... |
Tipo: Text |
|
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00628/73967/73326.pdf |
| |
|
|
Tonnard, Manon; Planquette, Hélène; Bowie, Andrew R.; Van Der Merwe, Pier; Gallinari, Morgane; Desprez De Gésincourt, Floriane; Germain, Yoan; Gourain, Arthur; Benetti, Marion; Reverdin, Gilles; Tréguer, Paul; Boutorh, Julia; Cheize, Marie; Menzel Barraqueta, Jan-lukas; Pereira-contreira, Leonardo; Shelley, Rachel; Lherminier, Pascale; Sarthou, Géraldine. |
Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf |
| |
|
|
|