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Karine Leblanc



My main research interest is the study of a siliceous phytoplankton group called diatoms as well as the silicon cycling in surface waters. Diatoms are an essential component of marine algae and are known to sediment rapidly out of the surface layer to the deep ocean, where parts of the carbon and other elements constituting their biomass can be sequestered. For this reason, diatoms are a key players in the CO2 exchange between the ocean and the atmosphere and determining the environmental conditions leading to their dominance or decline has global significance on marine foodwebs as well as on climate feedbacks. I’m mainly interested in characterizing how major nutrients availability limit diatom growth and control the shift between diatoms and other major phytoplanktonic groups in diverse oceanic systems, as well as how this affects the biological pump leading to export production. During my post-doc at the College of Marine Studies in Lewes (USA) I became interested in the role of trace metals such as iron and zinc on diatoms growth and on their elemental stoichiometry. This allowed me to participate to cruises in the sub-arctic and the sub-antarctic Pacific to investigate the impact of trace metal additions in HNLC areas (High Nutrient Low Chlorophyll), as well as collaborate on a series of T°, pCO2 controlled chemostat experiments int the Bering Sea and North Atlantic. I have also worked on the use of a fluorescent silicification probe (PDMPO) in order to identify within a mixed natural plankton community which species are the key players regarding Si uptake and to quantify their relative contribution to Si production. A routine protocol developped on an image analysis software coupled to epifluorescence microscopy now allows to quantify for each diatom cell (and hence species) the relative amount of PDMPO fluorescence which is proportional to Si production. I now continue my research at CNRS in Marseille (Luminy) where I continue to study diatom community structure, and how diversity, life strategies but also mortality modes may alter the efficiency of the biological pump. I have participated to several programs in oligotrophic regions of the Mediterranean Sea and the South Pacific, where diatoms are not necessarily dominant but have a specific ability to live in close associations with diazotrophic cyanobacteria. I am interested in using single-cell activity markers (viability, lipid, silicification) to better understand species-specific differences in elemental stoichiometry and physiological rates. I particularly enjoy field work and oceanographical cruises, notably in the Southern Ocean, where diatom communities are key components of the planktonic ecosystems.


Sinking Trichodesmium fixes nitrogen in the dark ocean

Mar Benavides , Sophie Bonnet , Frédéric Le Moigne , Gabrielle Armin , Keisuke Inomura
The International Society of Microbiologial Ecology Journal, 2022, 16 (10), pp.2398-2405. ⟨10.1038/s41396-022-01289-6⟩
Journal articles hal-03826322v1
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Deep particle stocks following the summer bloom around the Kerguelen islands: Insights into diatoms physiological state, community structure and mortality modes

Karine Leblanc , Augustin Lafond , Veronique Cornet , Justine Legras , Marie Barbara
Journal of Marine Systems, 2021, 222, pp.103609. ⟨10.1016/j.jmarsys.2021.103609⟩
Journal articles hal-03450616v1
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Green Edge ice camp campaigns: understanding the processes controlling the under-ice Arctic phytoplankton spring bloom

Philippe Massicotte , Rémi Amiraux , Marie-Pier Amyot , Philippe Archambault , Mathieu Ardyna
Earth System Science Data : Papers in open discussion, 2020, 12 (1), pp.151-176. ⟨10.5194/essd-12-151-2020⟩
Journal articles hal-02292721v1
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The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau)

Augustin Lafond , Karine Leblanc , Justine Legras , Veronique Cornet , Bernard Queguiner
Journal of Marine Systems, 2020, 212, pp.103458. ⟨10.1016/j.jmarsys.2020.103458⟩
Journal articles hal-03129381v1
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Late spring bloom development of pelagic diatoms in Baffin Bay

Augustin Lafond , Karine Leblanc , Bernard Queguiner , Brivaëla Moriceau , Aude Leynaert
Elementa: Science of the Anthropocene, 2019, 7, pp.44. ⟨10.1525/elementa.382⟩
Journal articles hal-02363555v1
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Nutrient availability and the ultimate control of the biological carbon pump in the western tropical South Pacific Ocean

Thierry Moutin , Thibaut Wagener , Mathieu Caffin , Alain Fumenia , Audrey Gimenez
Biogeosciences, 2018, 15 (9), pp.2961-2989. ⟨10.5194/bg-15-2961-2018⟩
Journal articles hal-01801747v1
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Nanoplanktonic diatoms are globally overlooked but play a role in spring blooms and carbon export

Karine Leblanc , Bernard Queguiner , Frederic Diaz , Veronique Cornet , Mónica Michel-Rodriguez
Nature Communications, 2018, 9 (1), pp.953. ⟨10.1038/s41467-018-03376-9⟩
Journal articles hal-02006275v1
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Combining laser diffraction, flow cytometry and optical microscopy to characterize a nanophytoplankton bloom in the Northwestern Mediterranean

R. Leroux , Gérald Grégori , F Carlotti , Karine Leblanc , Melilotus Thyssen
Progress in Oceanography, 2018, 163, pp.248-259. ⟨10.1016/j.pocean.2017.10.010⟩
Journal articles hal-01638096v1
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Silicon cycle in the tropical South Pacific: contribution to the global Si cycle and evidence for an active pico-sized siliceous plankton

Karine Leblanc , Veronique Cornet , Peggy Rimmelin-Maury , Olivier Grosso , Sandra Helias Nunige
Biogeosciences, 2018, 15 (18), pp.5595-5620. ⟨10.5194/bg-15-5595-2018⟩
Journal articles hal-01889901v1
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Influence of diatom diversity on the ocean biological carbon pump

Paul Tréguer , Chris Bowler , Brivaëla Moriceau , Stephanie Dutkiewicz , Marion Gehlen
Nature Geoscience, 2018, 11 (1), pp.27-37. ⟨10.1038/s41561-017-0028-x⟩
Journal articles hal-01667978v1
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Composition of diatom communities and their contribution to plankton biomass in the naturally iron-fertilized region of Kerguelen in the Southern Ocean

Marine Lasbleiz , Karine Leblanc , Leanne Armand , Urania Christaki , Clément Georges
FEMS Microbiology Ecology, 2016, 92 (11), pp.171. ⟨10.1093/femsec/fiw171⟩
Journal articles hal-01664911v1
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Phytoplankton community structure in the VAHINE mesocosm experiment

Karine Leblanc , Veronique Cornet , Mathieu Caffin , Martine Rodier , Anne Desnues
Biogeosciences, 2016, 13 (18), pp.5205-5219. ⟨10.5194/bg-13-5205-2016⟩
Journal articles hal-01664914v1
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Dinitrogen fixation and dissolved organic nitrogen fueled primary production and particulate export during the VAHINE mesocosm experiment (New Caledonia lagoon)

H Berthelot , T. Moutin , Stéphane L'Helguen , Karine Leblanc , S Hélias
Biogeosciences, 2015, 12 (13), pp.4099-4112. ⟨10.5194/bg-12-4099-2015⟩
Journal articles hal-01231737v1

Ecological niches of open ocean phytoplankton taxa

Philipp Brun , Meike Vogt , Mark R Payne , Nicolas Gruber , Colleen J O 'Brien
Limnology and Oceanography, 2015, 60 (3), pp.1020-1038. ⟨10.1002/lno.10074⟩
Journal articles hal-01664918v1
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Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean

Thomas W. Trull , D. M. Davies , Frank Dehairs , Anne-Julie Cavagna , Marine Lasbleiz
Biogeosciences, 2015, 12 (4), pp.1029-1056. ⟨10.5194/bg-12-1029-2015⟩
Journal articles hal-01207916v1
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Production regime and associated N cycling in the vicinity of Kerguelen Island, Southern Ocean

Anne-Julie Cavagna , François Fripiat , Marc Elskens , P. Mangion , L. Chirurgien
Biogeosciences, 2015, 12 (21), pp.6515-6528. ⟨10.5194/bg-12-6515-2015⟩
Journal articles hal-01812504v1
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Origin and fate of particulate and dissolved organic matter in a naturally iron-fertilized region of the Southern Ocean

Luc Tremblay , Jocelyne Caparros , Karine Leblanc , Ingrid Obernosterer
Biogeosciences, 2015, 12 (2), pp.607-621. ⟨10.5194/bg-12-607-2015⟩
Journal articles hal-01170213v1
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Seasonal evolution of net and regenerated silica production around a natural Fe-fertilized area in the Southern Ocean estimated with Si isotopic approaches

Ivia Closset , M. Lasbleiz , K. Leblanc , Bernard Queguiner , Anne-Julie Cavagna
Biogeosciences, 2014, 11 (20), pp.5827-5846. ⟨10.5194/bg-11-5827-2014⟩
Journal articles hal-01138239v1
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Pigments, elemental composition (C, N, P, and Si), and stoichiometry of particulate matter in the naturally iron fertilized region of Kerguelen in the Southern Ocean

M. Lasbleiz , Karine Leblanc , S. Blain , J. Ras , Veronique Cornet
Biogeosciences, 2014, 11 (20), pp.5931-5955. ⟨10.5194/bg-11-5931-2014⟩
Journal articles hal-01664909v1
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MAREDAT: towards a world atlas of MARine Ecosystem DATa

Erik Buitenhuis , M. Vogt , R. Moriarty , N. Bednarsek , S.C. Doney
Earth System Science Data, 2013, 5, pp.227-239. ⟨10.1594/PANGAEA.779970⟩
Journal articles hal-00997771v1
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A global diatom database - abundance, biovolume and biomass in the world ocean

Karine Leblanc , Javier Arístegui , Leanne Armand , Phillip Assmy , Beatriz Beker
Earth System Science Data, 2012, 4 (1), pp.149-165. ⟨10.5194/essd-4-149-2012⟩
Journal articles hal-00756934v2
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MAREDAT: towards a World Ocean Atlas of MARine Ecosystem DATa

E. Buitenhuis , M. Vogt , R. Moriarty , N. Bednaršek , S. Doney
Earth System Science Data : Papers in open discussion, 2012, 5 (2), pp.1077-1106. ⟨10.5194/essdd-5-1077-2012⟩
Journal articles hal-03278277v1
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Efficient silicon recycling in summer in both the Polar Frontal and Subantarctic Zones of the Southern Ocean

François Fripiat , Karine Leblanc , Marc Elskens , Anne-Julie Cavagna , Leanne Armand
Marine Ecology Progress Series, 2011, 435, pp.47-61. ⟨10.3354/meps09237⟩
Journal articles hal-00687945v1
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Deep silicon maxima in the stratified oligotrophic Mediterranean Sea.

Y. Crombet , Karine Leblanc , Bernard Queguiner , T. Moutin , Peggy Rimmelin
Biogeosciences, 2011, 8, pp.459-475. ⟨10.5194/bg-8-459-2011⟩
Journal articles hal-00700258v1
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Characterization of the bio-optical anomaly and diurnal variability of particulate matter, as seen from scattering and backscattering coefficients, in ultra-oligotrophic eddies of the Mediterranean Sea

Hubert Loisel , Vincent Vantrepotte , K. Norkvist , Xavier Meriaux , M. Kheireddine
Biogeosciences, 2011, 8, pp.3295-3317. ⟨10.5194/bg-8-3295-2011⟩
Journal articles hal-00688006v1

CO2 and vitamin B-12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom

Andrew L. King , Sergio A. Sanudo-Wilhelmy , Karine Leblanc , David A. Hutchins , Feixue Fu
The International Society of Microbiologial Ecology Journal, 2011, 5, pp.1388-1396. ⟨10.1038/ismej.2010.211⟩
Journal articles hal-00687942v1
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Effects of increased pCO2 and temperature on the North Atlantic spring bloom. III. Dimethylsulfoniopropionate

P.A. Lee , A.R. Rudisill , A.R. Neeley, , J.M. Maucher, , David A. Hutchins
Marine Ecology Progress Series, 2009, 388, pp.41-49. ⟨10.3354/meps08135⟩
Journal articles hal-00700399v1
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Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

J.M. Rose , Y. Feng , C. Gobler , R. Gutierrez , C.E. Hare
Marine Ecology Progress Series, 2009, 388, pp.27-40. ⟨10.3354/meps08134⟩
Journal articles hal-00700108v1
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Distribution of calcifying and silicifying phytoplankton in relation to environmental and biogeochemical parameters during the late stages of the 2005 North East Atlantic Spring Bloom

Karine Leblanc , C. E. Hare , Y. Feng , G. M. Berg , G. R. Ditullio
Biogeosciences, 2009, 6, pp.2155-2179
Journal articles hal-00703804v1

Measuring production-dissolution rates of marine biogenic silica by 30Si-isotope dilution using a high-resolution sector field inductively coupled plasma mass spectrometer

François Fripiat , Rudolph Corvaisier , Jacques Navez , Marc Elskens , Véronique Schoemann
Limnology and Oceanography : methods, 2009, 7, pp.470-478. ⟨10.4319/lom.2009.7.470⟩
Journal articles hal-00634582v1
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Effects of increased pCO2 and temperature on the North Atlantic spring bloom. I. The phytoplankton community and biogeochemical response

Y. Feng , C.E. Hare , Karine Leblanc , J.M. Rose , Y. Zhang
Marine Ecology Progress Series, 2009, 388, pp.13-25. ⟨10.3354/meps08133⟩
Journal articles hal-00700400v1
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Potential cobalt limitation of vitamin B12 synthesis in the North Atlantic Ocean

C. Panzeca , A. Beck , Karine Leblanc , G.T. Taylor , D.A. Hutchins
Global Biogeochemical Cycles, 2008, 22 (GB2029), 7 pp. ⟨10.1029/2007GB003124⟩
Journal articles hal-00702673v1
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Consequences of increased temperature and CO2 for phytoplankton community structure in the Bering Sea

C.E. Hare , Karine Leblanc , G.R. Ditullio , R. Kudela , Y. Zhang
Marine Ecology Progress Series, 2007, 352, pp.9-16. ⟨10.3354/meps07182⟩
Journal articles hal-00702676v1

Particulate iron dynamics during FeCycle in subantarctic waters southeast of New Zealand

R.D. Frew , D.A. Hutchins , S. Nodder , Sergio A. Sanudo-Wilhelmy , A. Tovar-Sanchez
Global Biogeochemical Cycles, 2006, 20 (GB1S93), 15 pp. ⟨10.1029/2005GB002558⟩
Journal articles hal-00702680v1
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Pressure effects on surface Mediterranean prokaryotes and biogenic silica dissolution during a diatom sinking experiment

Christian Tamburini , J. Garcin , G. Gregori , Karine Leblanc , P. Rimmelin
Aquatic Microbial Ecology, 2006, 43, pp.267-276. ⟨10.3354/ame043267⟩
Journal articles hal-00702531v1
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A seasonal study of diatom dynamics in the North Atlantic during the POMME experiment (2001): Evidence for Si limitation of the spring bloom

Karine Leblanc , Aude Leynaert , C. Fernandez , P. Rimmelin , Thierry Moutin
Journal of Geophysical Research. Oceans, 2005, 110, pp.C07S14. ⟨10.1029/2004JC002621⟩
Journal articles hal-00455625v1

FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters

P.W. Boyd , C.S. Law , D.A. Hutchins , E.R. Abraham , Peter L. Croot
Global Biogeochemical Cycles, 2005, 19 (GB4S20), 13 pp. ⟨10.1029/2005GB002494⟩
Journal articles hal-00702809v1
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Microbial community production, respiration and structure of the microbial food web of an ecosystem in the northeastern Atlantic Ocean

Anne Maixandeau , Dominique Lefèvre , Hera Karayanni , Urania Christaki , France van Wambeke
Journal of Geophysical Research. Oceans, 2005, 110 (C7), pp.C07S17. ⟨10.1029/2004JC002694⟩
Journal articles hal-00092669v1

The biological and biogeochemical consequences of phosphate scavenging onto phytoplankton cell surfaces.

Feixue Fu , Yaohong Zhang , Karine Leblanc , Sergio A. Sanudo-Wilhelmy
Limnology and Oceanography, 2005, 50 (5), pp.1459-1472
Journal articles hal-00688046v1

Fe and Zn effects on the Si cycle and diatom community structure in two contrasting high and low-silicate HNLC areas

K. Leblanc , C.E. Hare , P.W. Boyd , K. Bruland , B. Sohst
Deep Sea Research Part I: Oceanographic Research Papers, 2005, 52 (10), pp.1842 - 1864. ⟨10.1016/j.dsr.2005.06.005⟩
Journal articles hal-01767564v1

Zinc availability and alkaline phosphatase activity in Emiliania huxleyi: Implications for Zn-P co-limitation in the ocean

Y. Shaked , Y. Xu , Karine Leblanc , F.M. Morel
Limnology and Oceanography, 2005, 51 (1), pp.299-309. ⟨10.4319/lo.2006.51.1.0299⟩
Journal articles hal-00702795v1

New applications of a biogenic silica deposition fluorophore in the study of oceanic diatoms

K. Leblanc , D.A. Hutchins
Limnology and Oceanography : methods, 2005, 3, pp.462-476. ⟨10.4319/lom.2005.3.462⟩
Journal articles hal-00702801v1
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Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

K. Leblanc , Bernard Queguiner , Patrick Raimbault , N. Garcia
Biogeosciences Discussions, 2005, 2 (3), pp.551-580
Journal articles hal-00330212v1
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Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

K. Leblanc , Bernard Queguiner , Patrick Raimbault , N. Garcia
Biogeosciences, 2005, 2 (3), pp.219-229. ⟨10.5194/bg-2-219-2005⟩
Journal articles hal-00330311v1
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Siliceous phytoplankton production and export related to trans-frontal dynamics of the Almeria-Oran frontal system (western Mediterranean Sea) during winter

Karine Leblanc , Bernard Queguiner , L. Prieur , Hervé Claustre , K. Oubelkheir
Journal of Geophysical Research. Oceans, 2004, 109, pp.C07010. ⟨10.1029/2003JC001878⟩
Journal articles hal-00702535v1
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Availability of iron and major nutrients for phytoplankton in the northeast Atlantic Ocean

Stéphane Blain , Cécile Guieu , Hervé Claustre , Karine Leblanc , T. Moutin
Limnology and Oceanography, 2004, 49 (6), pp.2095-2104. ⟨10.4319/lo.2004.49.6.2095⟩
Journal articles hal-00702539v1

Silicon cycle in the Northwestern Mediterranean Sea: seasonal study of a coastal oligotrophic site.

Karine Leblanc , Bernard Queguiner , Nicole Garcia , Peggy Rimmelin , Patrick Raimbault
Oceanologica Acta, 2003, 26 (4), pp.339-355. ⟨10.1016/S0399-1784(03)00035-5⟩
Journal articles hal-00700111v1
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Mesoscale surface distribution of biogeochemical characteristics associated with a frontal system in the Crozet Basin during austral summer 1999.

Michel Fiala , B. Delille , Catherine-Marie Dubreuil , E. Kopcynska , Karine Leblanc
Marine Ecology Progress Series, 2003, 249, pp.1-14. ⟨10.3354/meps249001⟩
Journal articles hal-00700116v1

Particulate biogenic silica and carbon production rates and particulate matter distribution in the Indian sector of the Subantarctic Ocean

Karine Leblanc , Bernard Queguiner , Michel Fiala , Stéphane Blain , J. Morvan
Deep Sea Research Part II: Topical Studies in Oceanography, 2002, 49 (16), pp.3189-3206. ⟨10.1016/S0967-0645(02)00078-4⟩
Journal articles hal-02500690v1

Particulate biogenic silica and carbon production rates and particulate matter distribution in the Indian sector of the Subantarctic Ocean

Karine Leblanc , Bernard Queguiner , Michel Fiala , Stéphane Blain , J. Morvan
Deep Sea Research Part II: Topical Studies in Oceanography, 2002, 49 (16), pp.3189-3206. ⟨10.1016/S0967-0645(02)00078-4⟩
Journal articles hal-00700118v1
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Is desert dust making oligotrophic waters greener?

Hervé Claustre , A. Morel , S.B. Hooker, , M. Babin , David Antoine
Geophysical Research Letters, 2002, 29 (10), pp.107. ⟨10.1029/2001GL014056⟩
Journal articles hal-00702800v1