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Fonseca-batista, Debany; Li, Xuefeng; Riou, Virginie; Michotey, Valérie; Deman, Forian; Fripiat, François; Guasco, Sophie; Brion, Natacha; Lemaitre, Nolwenn; Tonnard, Manon; Gallinari, Morgane; Planquette, Hélène; Planchon, Frédéric; Sarthou, Géraldine; Elskens, Marc; Laroche, Julie; Chou, Lei; Dehairs, Frank. |
Diazotrophic activity and primary production (PP) were investigated along two transects (Belgica BG2014/14 and GEOVIDE cruises) off the western Iberian Margin and the Bay of Biscay (38.8–46.5°N; 8.0–19.7°W) in May 2014 close to the end of the spring bloom. We report substantial N2 fixation activities, reaching up to 65nmolNL−1d−1 and 1533µmolNm−2d−1 close to the Iberian Margin between 38.8°N and 40.7°N. Similar figures in the basin have only been reported in the temperate and tropical western North Atlantic waters with coastal, shelf or mesohaline characteristics, as opposed to the mostly open ocean conditions studied here. In agreement with previous studies, the qualitative assessment of nifH gene diversity (encoding the nitrogenase enzyme that fixes N2)... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00461/57266/59317.pdf |
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Louropoulou, Evangelia; Gledhill, Martha; Browningi, Thomas J.; Desai, Dhwani K.; Barraqueta, Jan-lukas Menzel; Tonnard, Manon; Sarthou, Geraldine; Planquette, Helene; Bowie, Andrew R.; Schmitz, Ruth A.; Laroche, Julie; Achterberg, Eric P.. |
Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (< 1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (> 0.7 mu m) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median =... |
Tipo: Text |
Palavras-chave: Heme b; North Atlantic; Phytoplankton; Diatoms; Iron; Limitation; GEOTRACES; GEOVIDE. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00508/61940/66029.pdf |
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Sarthou, Geraldine; Lherminier, Pascale; Achterberg, Eric P.; Alonso-perez, Fernando; Bucciarelli, Eva; Boutorh, Julia; Bouvier, Vincent; Boyle, Edward A.; Branellec, Pierre; Carracedo, Lidia I.; Casacuberta, Nuria; Castrillejo, Maxi; Cheize, Marie; Pereira, Leonardo Contreira; Cossa, Daniel; Daniault, Nathalie; De Saint-leger, Emmanuel; Dehairs, Frank; Deng, Feifei; De Gesincourt, Floriane Desprez; Devesa, Jeremy; Foliot, Lorna; Fonseca-batista, Debany; Gallinari, Morgane; Garcia-ibanez, Maribel I.; Gourain, Arthur; Grossteffan, Emilie; Hamon, Michel; Heimburger, Lars Eric; Henderson, Gideon M.; Jeandel, Catherine; Kermabon, Catherine; Lacan, Francois; Le Bot, Philippe; Le Goff, Manon; Le Roy, Emilie; Lefebvre, Alison; Leizour, Stephane; Lemaitre, Nolwenn; Masque, Pere; Menage, Olivier; Barraqueta, Jan-lukas Menzel; Mercier, Herle; Perault, Fabien; Perez, Fiz F; Planquette, Helene; Planchon, Frederic; Roukaerts, Arnout; Sanial, Virginie; Sauzede, Raphaelle; Schmechtig, Catherine; Shelley, Rachel U.; Stewart, Gillian; Sutton, Jill; Tang, Yi; Tisnerat-laborde, Nadine; Tonnard, Manon; Treguer, Paul; Van Beek, Pieter; Zurbrick, Cheryl M.; Zunino Rodriguez, Patricia. |
The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this special issue (https://www.biogeosciences.net/special_ issue900.html), results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 18 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue. |
Tipo: Text |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58178/60685.pdf |
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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... |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf |
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