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| Whitby, Hannah; Planquette, Helene; Cassar, Nicolas; Bucciarelli, Eva; Osburn, Christopher L.; Janssen, David J.; Cullen, Jay T.; González, Aridane G.; Völker, Christoph; Sarthou, Geraldine. |
| Primary production by phytoplankton represents a major pathway whereby atmospheric CO2 is sequestered in the ocean, but this requires iron, which is in scarce supply. As over 99% of iron is complexed to organic ligands, which increase iron solubility and microbial availability, understanding the processes governing ligand dynamics is of fundamental importance. Ligands within humic-like substances have long been considered important for iron complexation, but their role has never been explained in an oceanographically consistent manner. Here we show iron co-varying with electroactive humic substances at multiple open ocean sites, with the ratio of iron to humics increasing with depth. Our results agree with humic ligands composing a large fraction of the... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73388/72598.pdf |
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| Wang, Seaver; Tang, Weiyi; Delage, Erwan; Gifford, Scott; Whitby, Hannah; González, Aridane G.; Eveillard, Damien; Planquette, Helene; Cassar, Nicolas. |
| Variation in the microbial cycling of nutrients and carbon in the ocean is an emergent property of complex planktonic communities. While recent findings have considerably expanded our understanding of the diversity and distribution of nitrogen (N2) fixing marine diazotrophs, knowledge gaps remain regarding ecological interactions between diazotrophs and other community members. Using quantitative 16S and 18S V4 rDNA amplicon sequencing, we surveyed eukaryotic and prokaryotic microbial communities from samples collected in August 2016 and 2017 across the Western North Atlantic. Leveraging and significantly expanding an earlier published 2015 molecular dataset, we examined microbial community structure and ecological co-occurrence relationships associated... |
| Tipo: Text |
Palavras-chave: Element cycles; Marine biology. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79677/82454.pdf |
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| Charette, Matthew A.; Kipp, Lauren E.; Jensen, Laramie T.; Dabrowski, Jessica S.; Whitmore, Laura M.; Fitzsimmons, Jessica N.; Williford, Tatiana; Ulfsbo, Adam; Jones, Elizabeth; Bundy, Randelle M.; Vivancos, Sebastian M.; Pahnke, Katharina; John, Seth G.; Xiang, Yang; Hatta, Mariko; Petrova, Mariia V.; Heimbürger-boavida, Lars-eric; Bauch, Dorothea; Newton, Robert; Pasqualini, Angelica; Agather, Alison M.; Amon, Rainer M.w.; Anderson, Robert F.; Andersson, Per S.; Benner, Ronald; Bowman, Katlin L.; Edwards, R. Lawrence; Gdaniec, Sandra; Gerringa, Loes J.a.; González, Aridane G.; Granskog, Mats; Haley, Brian; Hammerschmidt, Chad R.; Hansell, Dennis A.; Henderson, Paul B.; Kadko, David C.; Kaiser, Karl; Laan, Patrick; Lam, Phoebe J.; Lamborg, Carl H.; Levier, Martin; Li, Xianglei; Margolin, Andrew R.; Measures, Chris; Middag, Rob; Millero, Frank J.; Moore, Willard S.; Paffrath, Ronja; Planquette, Helene; Rabe, Benjamin; Reader, Heather; Rember, Robert; Rijkenberg, Micha J.a.; Roy-barman, Matthieu; Rutgers Van Der Loeff, Michiel; Saito, Mak; Schauer, Ursula; Schlosser, Peter; Sherrell, Robert M.; Shiller, Alan M.; Slagter, Hans; Sonke, Jeroen E.; Stedmon, Colin; Woosley, Ryan J.; Valk, Ole; Van Ooijen, Jan; Zhang, Ruifeng. |
| A major surface circulation feature of the Arctic Ocean is the Transpolar Drift (TPD), a current that transports river‐influenced shelf water from the Laptev and East Siberian Seas toward the center of the basin and Fram Strait. In 2015, the international GEOTRACES program included a high‐resolution pan‐Arctic survey of carbon, nutrients, and a suite of trace elements and isotopes (TEIs). The cruises bisected the TPD at two locations in the central basin, which were defined by maxima in meteoric water and dissolved organic carbon concentrations that spanned 600 km horizontally and ~25‐50 m vertically. Dissolved TEIs such as Fe, Co, Ni, Cu, Hg, Nd, and Th, which are generally particle‐reactive but can be complexed by organic matter, were observed at... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00620/73223/72435.pdf |
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