Nolwenn Lemaitre

Marie Skłodowska-Curie Research Fellow

CNRS

Email : nolwenn.lemaitreDear bot, you won't get my mail address@and my domain...univ-tlse3.fr

TIM: Toulouse Isotopie Marine

Marie Skłodowska-Curie Research Fellow

CV / functions

since 2022 : Marie Skłodowska-Curie Research Fellow. CNRS – LEGOS (France)

2017-2022 : Postdoctoral researcher. ETH Zurich – Institute of Geochemistry and Petrology (Switzerland)

2013-2017 : PhD student. UBO – LEMAR (France) and VUB (Belgium)

Research

I am a biogeochemist specialised in understanding the marine biogeochemical cycles of trace metals and their isotopes. Despite their very low concentrations, these bioactive elements (cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn)) are essential to the development of phytoplankton and, more generally, to the functioning of marine ecosystems. They directly influence the carbon pump. Despite the importance of these metals in the ocean, their biogeochemical cycles remain poorly understood. My aim is therefore to gain a better understanding of these marine biogeochemical cycles, which involves identifying the sources and sinks of trace metals in the ocean, their interactions with biology and with the various mineral phases (authigenic and lithogenic) and their transport by water masses. I use different tracers to better understand and quantify the multitude of chemical, physical and biological processes that influence their distribution. In particular, I use natural thorium-234 (234Th) and biogenic particulate barium (Baxs) for export and remineralisation fluxes, and stable isotopes of metals, such as those of copper (δ65Cu), nickel (δ60Ni) and zinc (δ66Zn) to identify sources, sinks and internal processes of these metals in the ocean.

Publications

R. van Horsten, H. Planquette, G. Sarthou, T. J. Ryan-Keogh, N. Lemaitre, T. N. Mtshali, A. Roychoudhury, E. Bucciarelli, 2022. Early winter barium excess in the Southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise). Biogeosciences, 19, 3209-3224, 10.5194/bg-19-3209-2022.

N. Lemaitre, J. Du, G. F. de Souza, C. Archer, D. Vance, 2022. The essential bioactive role of nickel in the oceans: evidence from nickel isotopes. Earth and Planetary Science Letters, 584, 117513, 10.1016/j.epsl.2022.117513.

M. Lagarde, N. Lemaitre, H. Planquette, M. Grenier, M. Belhadj, P. Lherminier, C. Jeandel, 2020. Particulate rare earth element behavior in the North Atlantic (GEOVIDE cruise). Biogeosciences, 17, 5539-5561, 10.5194/bg-17-5539-2020.

N. Lemaitre, H. Planquette, F. Dehairs, F. Planchon, G. Sarthou, M. Gallinari, S. Roig, C. Jeandel, M. Castrillejo. Particulate trace element export in the North Atlantic (GEOTRACES GA01 transect, GEOVIDE cruise), 2020. ACS Earth and Space Chemistry, 10.1021/acsearthspacechem.0c00045.

E. E. Black, S. S. Kienast, N. Lemaitre, P. J. Lam, R. F. Anderson, H. Planquette, F. Planchon, K. O. Buesseler, 2020. Ironing out Fe residence time in the dynamic upper ocean. Global Biogeochemical Cycles, 34, 1-17, 10.1029/2020GB006592.

G. Bayon, N. Lemaitre, J-A Barrat, X. Wang, D. Feng, S. Duperron, 2020. Microbial utilization of rare earth elements at cold seeps related to aerobic methane oxidation. Chemical Geology, 555, 119832, 10.1016/j.chemgeo.2020.119832.

N. Lemaitre, G. de Souza, C. Archer, R.-M. Wang, H. Planquette, G. Sarthou, D. Vance, 2020. Pervasive sources of isotopically light zinc in the North Atlantic Ocean. Earth and Planetary Science Letters, 539, 116216, 10.1016/j.epsl.2020.116216

Y. Tang, N. Lemaitre, M. Castrillejo, M. Roca-Martí, P. Masqué, G. Stewart, 2019. The export flux of particulate organic carbon derived from ²¹⁰Po/²¹⁰Pb disequilibria along the North Atlantic GEOTRACES GA01 (GEOVIDE) transect. Biogeosciences, 16, 309-327, 10.5194/bg-16-309-2019.

D. Fonseca-Batista, X. Li, V. Riou, V. Michotey, F. Deman, F. Fripiat, S. Guasco, N. Brion, N. Lemaitre, M. Tonnard, M. Gallinari, H. Planquette, F. Planchon, G. Sarthou, M. Elskens, J. LaRoche, L. Chou, F. Dehairs, 2019. Evidence of high N₂ fixation rates in productive waters of the temperate Northeast Atlantic. Biogeosciences, 16, 999-1017, 10.5194/bg-16-999-2019.

A. Gourain, H. Planquette, M. Cheize, N. Lemaitre, J.-L. Menzel Barraqueta, R. Shelley, P. Lherminier, G. Sarthou, 2019. Inputs and processes affecting the distribution of particulate iron in the North Atlantic along the GEOVIDE (GEOTRACES GA01) section. Biogeosciences, 16, 1563-1582, 10.5194/bg-16-1563-2019.

G. Sarthou, P. Lherminer, E.P. Achterberg, F. Alonso‐Pérez, E. Bucciarelli, J. Boutorh, V. Bouvier, E.A. Boyle, P. Branellec, L.I. Carracedo, N. Casacuberta, M. Castrillejo, M. Cheize, L. Contreira Pereira, D. Cossa, N. Daniault, E. De Saint‐Léger, F. Dehairs, F. Deng, F. Desprez de Gésincourt, J. Devesa, L. Foliot, D. Fonseca‐Batista, M. Gallinari, M.I. García‐Ibáñez, A. Gourain, E. Grossteffan, M. Hamon, L.E. Heimbürger, G. Henderson, C. Jeandel, C. Kermabon, F. Lacan, P. Le Bot, M. Le Goff, E. Le Roy, A. Lefèbvre, S. Leizour, N. Lemaitre, P. Masqué, O. Ménage, J.-L. Menzel Barraqueta, H. Mercier, F. Perault, F.F Pérez, H. Planquette, F. Planchon, A. Roukaerts, V. Sanial, R. Sauzède, R.U. Shelley, G. Stewart, J. Sutton, Y. Tang, N. Tisnérat‐Laborde, M. Tonnard, P. Tréguer, P. van Beek, C.M. Zurbrick, P. Zunino, 2018. Introduction to the French GEOTRACES North Atlantic transect (GA01): GEOVIDE cruise. Biogeosciences, 15, 7097-7109, 10.5194/bg-15-7097-2018.

M. Grenier, E. Garcia-Solsona, N. Lemaitre, T. Trull, V. Bouvier, P. Nonnotte, P. van Beek, M. Souhaut, F. Lacan, C. Jeandel, 2018. Differentiating lithogenic supplies, water mass transport and biological processes on and off the Kerguelen Plateau using rare earth element concentrations and neodymium isotopic compositions. Frontiers in Marine Sciences, 5, 426, 10.3389/fmars.2018.00426.

N. Lemaitre, F. Planchon, H. Planquette, F. Dehairs, D. Fonseca-Batista, A. Roukaerts, F. Deman, Y. Tang, C. Mariez, G. Sarthou, 2018. High variability of particulate organic carbon export along the North Atlantic GEOTRACES section GA01 as deduced from 234Th fluxes. Biogeosciences, 15, 6417-6437, 10.5194/bg-15-6417-2018.

Y. Tang, M. Castrillejo, M. Roca-Martí, P. Masqué, N. Lemaitre, and G. Stewart, 2018. Distributions of total and size-fractionated particulate 210Po and 210Pb activities along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise. Biogeosciences, 15, 1-17, 10.5194/bg-15-1-2018.

N. Lemaitre, H. Planquette, F. Planchon, G. Sarthou, S. Jacquet, M.I. Garcia-Ibáñez, A. Gourain, M. Cheize, L. Monin, L. André, P. Laha, H. Terryn, F. Dehairs, 2018. Particulate barium tracing of significant mesopelagic carbon remineralization in the North Atlantic. Biogeosciences, 15, 2289-2307, 10.5194/bg-15-2289-2018.

N. Lemaitre, H. Planquette, F. Dehairs, P. Van der Merwe, A.R. Bowie, T.W. Trull, E.C. Laurenceau-Cornec, D. Davies, C. Bollinger, M. Le Goff, E. Grossteffan, F. Planchon, 2016. Impact of the natural Fe-fertilization on the magnitude, stoichiometry and efficiency of BSi, PN and PFe export fluxes. Deep-Sea Research, 117, 11-27, 10.1016/j.dsr.2016.09.002.

N. Lemaitre, G. Bayon, H. Ondréas, J.C. Caprais, N. Freslon, C. Bollinger, M.L. Rouget, A. de Prunelé, L. Ruffine, K. Olu-Le Roy, G. Sarthou, 2014. Trace element behaviour at cold seeps and the potential export of dissolved iron to the ocean. Earth and Planetary Science Letters, 404, 376-388, 10.01016/j.epsl.2014.08.014.

S. Duperron, S.M. Gaudron, N. Lemaitre, G. Bayon, 2014. A microbiological and biogeochemical investigation of the cold seep tubeworm Escarpia southwardae (Annelida: Siboglinidae): Symbiosis and trace element composition of the tube. Deep-Sea-Research I, 90, 105-114, 10.1016/j.dsr.2014.05.006.

Projects

IsoMargin (MSCA, PI N. Lemaitre). 2022-2024. Isotopes of micronutrients to trace margin sediment fluxes to the ocean

SWINGS (ANR, PIs H. Planquette, LEMAR & C. Jeandel, LEGOS). 2020-2024. GEOTRACES Section in the South Indian Ocean (La Réunion-Kerguelen Islands)

ACE (EPFL, Swiss Polar Institute and Ferring Pharmaceuticals). 2016-2017. Antarctic Circumnavigation Expedition

GEOVIDE (ANR, PIs G. Sarthou, LEMAR & P. Lherminier, LOPS). 2014-2018. GEOTRACES section in the North Atlantic (Portugal-Greenland-Newfoundland)

KEOPS2 (INSU-ANR, PI S. Blain, LOMIC). 2011-2014. Kerguelen Ocean and plateau compared study 2.

Teaching

Teaching and outreach

May 2023. Radio interviews (Radio Presence, ‘La science et nous’) : Chemical equilibrium in the oceans and Ocean research cruises
March 2023. Presentation of the research profession to students of a primary school (Blagnac) as part of the International Days of Women and Girls in Science (2h).
December 2022 (University Toulouse, France). Supervision of the visit to the Golfech nuclear power plant, Master students in Ocean, Atmosphere and Climate Sciences (4h).
November 2022 (University Toulouse, France). Committee member of the oral presentations for the ‘Basics in Oceanography’ class for Master students (3h).
May 2022. Article in the online journal ‘Connected Oceans’: Nolwenn Lemaitre, Winner of a European Fellowship
May 2022. Phone conference with a visual impaired audience (Les Chemins Buissonniers)
March 2022. Online TV report (TV Trégor): Dans le sillage de Nolwenn Lemaître
December 2021. Feedback presentation about the SWINGS cruise to the students of primary school (Locquirec, 2h) and highschool (Morlaix, 2×2h; France)
January-March 2021. Sharing of my diary during the SWINGS cruise
December 2020. Presentation of the SWINGS cruise (2h) to the primary school of Locquirec (France)
April 2021. Article in the journal ‘La mer, notre avenir’ (Ouest France): De la voile à l’océanographie
March 2021. Radio interview (RTS, ‘CQFD’): The SWINGS cruise: unravelling the secrets of the Southern Ocean
August 2019. Participation to the card game ‘Mendeleieva’ (association Women & Sciences)
September 2018 (Viseu, Portugal) & April 2019 (Zurich, Switzerland). Art Lab, Conciliate science and art around the theme of water: The key role of the ocean in our climate (Science Xplore, 1 week/event)
September 2017 (ETH Zurich, Switzerland). Assistant during a Geochemistry class for Bachelor students (2h).
March 2016 (VUB, Belgium). Teaching nutrient sampling and analyses at sea for Master students (2 days).
February 2015. Three Minute Thesis (UBO, France)

Student supervision

October 2019 – April 2021. Xingchao Zhang – PhD student (ETH Zurich, Switzerland)
Tracing anthropogenic aerosol trace metal sources using Pb, Ni and Zn isotopes

March-June 2020. Lars Kraus – Bachelor student (ETH Zurich, Switzerland)
Trace metal cycling in the Namibian oxygen minimum zone

March-June 2019. Ricardo Zamora – Bachelor student (ETH Zurich, Switzerland)
The Southern Ocean controls on oceanic nickel concentrations and isotopes

January – March 2017. Clarisse Mariez – Master student (LEMAR, Brest, France)
Carbon and Nitrogen isotope signatures of organic matter

January – March 2017. Stéphane Roig – Master student (LEMAR, Brest, France)
Biogenic silica dynamics in the North Atlantic

Nolwenn Lemaitre

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