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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 |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00692/80407/83515.pdf |
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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... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00643/75509/76356.pdf |
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Mansour, Joost Samir; Norlin, Andreas; Llopis Monferrer, Natalia; L'Helguen, Stéphane; Not, Fabrice. |
Rhizaria are large protistan cells that have been shown to be a major component of the planktic community in the oceans and contribute significantly to major biogeochemical cycles such as carbon or silicon. However, unlike for many other protists, limited data is available on rhizarian cellular carbon (C) and nitrogen (N) content and cell volume. Here we present novel C and N mass to volume equations and ratios for nine Rhizaria taxa belonging to Radiolaria (i.e., Collozoum, Sphaerozoum, Collosphaeridae, Acantharia, Nassellaria, and Spumellaria) and Phaeodaria (i.e., Aulacantha, Protocystis, and Challengeria). The C and N content of collodarian cells was significantly correlated to cell volume as expressed by the mass : vol equations ng C cell−1 =... |
Tipo: Text |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79596/82288.pdf |
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