Réseaux sociaux


Nombre de documents



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.

Article dans une revue34 documents

  • Thierry Moutin, Thibaut Wagener, Mathieu Caffin, Alain Fumenia, Audrey Gimenez, et al.. Nutrient availability and the ultimate control of the biological carbon pump in the western tropical South Pacific Ocean. Biogeosciences, European Geosciences Union, 2018, 15 (9), pp.2961-2989. 〈10.5194/bg-15-2961-2018〉. 〈hal-01801747〉
  • Karine Leblanc, Bernard Queguiner, Frédéric Diaz, Veronique Cornet, Mónica Michel-Rodriguez, et al.. Nanoplanktonic diatoms are globally overlooked but play a role in spring blooms and carbon export. Nature Communications, Nature Publishing Group, 2018, 9 (1), pp.953. 〈10.1038/s41467-018-03376-9〉. 〈hal-02006275〉
  • Paul Tréguer, Chris Bowler, Brivaëla Moriceau, Stephanie Dutkiewicz, Marion Gehlen, et al.. Influence of diatom diversity on the ocean biological carbon pump. Nature Geoscience, Nature Publishing Group, 2018, 11, pp.27-37. 〈10.1038/s41561-017-0028-x〉. 〈hal-01667978〉
  • Karine Leblanc, Veronique Cornet, Peggy Rimmelin-Maury, Olivier Grosso, Sandra Helias-Nunige, et al.. Silicon cycle in the tropical South Pacific: contribution to the global Si cycle and evidence for an active pico-sized siliceous plankton. Biogeosciences, European Geosciences Union, 2018, 15 (18), pp.5595-5620. 〈10.5194/bg-15-5595-2018〉. 〈hal-01889901〉
  • Marine Lasbleiz, Karine Leblanc, Leanne Armand, Urania Christaki, Clément Georges, et al.. Composition of diatom communities and their contribution to plankton biomass in the naturally iron-fertilized region of Kerguelen in the Southern Ocean. FEMS Microbiology Ecology, Wiley-Blackwell, 2016, 92 (11), pp.fiw171. 〈10.1093/femsec/fiw171〉. 〈hal-01664911〉
  • Karine Leblanc, Veronique Cornet, Mathieu Caffin, Martine Rodier, Anne Desnues, et al.. Phytoplankton community structure in the VAHINE mesocosm experiment. Biogeosciences, European Geosciences Union, 2016, 13 (18), pp.5205-5219. 〈10.5194/bg-13-5205-2016〉. 〈hal-01664914〉
  • H Berthelot, T Moutin, S L 'Helguen, Karine Leblanc, S Hélias, et al.. Dinitrogen fixation and dissolved organic nitrogen fueled primary production and particulate export during the VAHINE mesocosm experiment (New Caledonia lagoon). Biogeosciences, European Geosciences Union, 2015, 12, pp.4099-4112. 〈10.5194/bg-12-4099-2015〉. 〈hal-01231737〉
  • Luc Tremblay, Jocelyne Caparros, Karine Leblanc, Ingrid Obernosterer. Origin and fate of particulate and dissolved organic matter in a naturally iron-fertilized region of the Southern Ocean. Biogeosciences, European Geosciences Union, 2015, 12 (2), pp.607-621. 〈10.5194/bg-12-607-2015〉. 〈hal-01170213〉
  • M. Lasbleiz, Karine Leblanc, S. Blain, J. Ras, Veronique Cornet, et al.. 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. Biogeosciences, European Geosciences Union, 2014, 11 (20), pp.5931-5955. 〈10.5194/bg-11-5931-2014〉. 〈hal-01664909〉
  • Karine Leblanc, Javier Arístegui, Leanne Armand, Phillip Assmy, Beatriz Beker, et al.. A global diatom database - abundance, biovolume and biomass in the world ocean. Earth System Science Data, Copernicus Publications, 2012, 4 (1), pp.149-165. 〈10.5194/essd-4-149-2012〉. 〈hal-00756934〉
  • Y. Crombet, Karine Leblanc, Bernard Queguiner, T. Moutin, Peggy Rimmelin, et al.. Deep silicon maxima in the stratified oligotrophic Mediterranean Sea.. Biogeosciences, European Geosciences Union, 2011, 8, pp.459-475. 〈10.5194/bg-8-459-2011〉. 〈hal-00700258〉
  • Hubert Loisel, Vincent Vantrepotte, K. Norkvist, Xavier Meriaux, M. Kheireddine, et al.. 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. Biogeosciences, European Geosciences Union, 2011, 8, pp.3295-3317. 〈10.5194/bg-8-3295-2011〉. 〈hal-00688006〉
  • Francois Fripiat, Karine Leblanc, Marc Elskens, Anne-Julie Cavagna, Leanne Armand, et al.. Efficient silicon recycling in summer in both the Polar Frontal and Subantarctic Zones of the Southern Ocean. Marine Ecology Progress Series, Inter Research, 2011, 435, pp.47-61. 〈10.3354/meps09237〉. 〈hal-00687945〉
  • Andrew L. King, Sergio A. Sanudo-Wilhelmy, Karine Leblanc, David A. Hutchins, Feixue Fu. CO2 and vitamin B-12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom. ISME Journal, Nature Publishing Group, 2011, 5, pp.1388-1396. 〈10.1038/ismej.2010.211〉. 〈hal-00687942〉
  • Xavier Durrieu de Madron, Cécile Chanut-Guieu, Richard Sempere, Pascal Conan, Daniel Cossa, et al.. Marine ecosystems' responses to climatic and anthropogenic forcings in the Mediterranean. Progress in Oceanography, Elsevier, 2011, 91 (2), pp.97-166. 〈10.1016/J.POCEAN.2011.02.003〉. 〈hal-00753879〉
  • F. Fripiat, Rudolph Corvaisier, Jacques Navez, M. Elskens, Véronique Schoemann, et al.. Measuring production-dissolution rates of marine biogenic silica by 30Si-isotope dilution using a high-resolution sector field inductively coupled plasma mass spectrometer. Limnology and Oceanography : methods, 2009, 7, pp.470-478. 〈10.4319/lom.2009.7.470〉. 〈hal-00634582〉
  • Karine Leblanc, C. E. Hare, Y. Feng, G. M. Berg, G. R. Ditullio, et al.. 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. Biogeosciences, European Geosciences Union, 2009, 6, pp.2155-2179. 〈hal-00703804〉
  • P.A. Lee, A.R. Rudisill, A.R. Neeley,, J.M. Maucher,, David A. Hutchins, et al.. Effects of increased pCO2 and temperature on the North Atlantic spring bloom. III. Dimethylsulfoniopropionate. Marine Ecology Progress Series, Inter Research, 2009, 388, pp.41-49. 〈10.3354/meps08135〉. 〈hal-00700399〉
  • Y. Feng, C.E. Hare, Karine Leblanc, J.M. Rose, Y. Zhang, et al.. Effects of increased pCO2 and temperature on the North Atlantic spring bloom. I. The phytoplankton community and biogeochemical response. Marine Ecology Progress Series, Inter Research, 2009, 388, pp.13-25. 〈10.3354/meps08133〉. 〈hal-00700400〉
  • C. Panzeca, A. Beck, Karine Leblanc, G.T. Taylor, D.A. Hutchins, et al.. Potential cobalt limitation of vitamin B12 synthesis in the North Atlantic Ocean. Global Biogeochemical Cycles, American Geophysical Union, 2008, 22 (GB2029), 7 pp. 〈10.1029/2007GB003124〉. 〈hal-00702673〉
  • C.E. Hare, Karine Leblanc, G.R. Ditullio, R. Kudela, Y. Zhang, et al.. Consequences of increased temperature and CO2 for phytoplankton community structure in the Bering Sea. Marine Ecology Progress Series, Inter Research, 2007, 352, pp.9-16. 〈10.3354/meps07182〉. 〈hal-00702676〉
  • R.D. Frew, D.A. Hutchins, S. Nodder, Sergio Sanudo-Wilhelmy, A. Tovar-Sanchez, et al.. Particulate iron dynamics during FeCycle in subantarctic waters southeast of New Zealand. Global Biogeochemical Cycles, American Geophysical Union, 2006, 20 (GB1S93), 15 pp. 〈10.1029/2005GB002558〉. 〈hal-00702680〉
  • C. Tamburini, J. Garcin, G. Gregori, Karine Leblanc, P. Rimmelin, et al.. Pressure effects on surface Mediterranean prokaryotes and biogenic silica dissolution during a diatom sinking experiment. Aquatic Microbial Ecology, Inter Research, 2006, 43, pp.267-276. 〈10.3354/ame043267〉. 〈hal-00702531〉
  • Karine Leblanc, Aude Leynaert, C. Fernandez, P. Rimmelin, Thierry Moutin, et al.. A seasonal study of diatom dynamics in the North Atlantic during the POMME experiment (2001): Evidence for Si limitation of the spring bloom. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2005, 110, pp.C07S14. 〈10.1029/2004JC002621〉. 〈hal-00455625〉
  • Y. Shaked, Y. Xu, Karine Leblanc, F.M. Morel. Zinc availability and alkaline phosphatase activity in Emiliania huxleyi: Implications for Zn-P co-limitation in the ocean. Limnology and Oceanography, Association for the Sciences of Limnology and Oceanography, 2005, 51 (1), pp.299-309. 〈10.4319/lo.2006.51.1.0299〉. 〈hal-00702795〉
  • Feixue Fu, Yaohong Zhang, Karine Leblanc, Sergio Sanudo-Wilhelmy. The biological and biogeochemical consequences of phosphate scavenging onto phytoplankton cell surfaces.. Limnology and Oceanography, Association for the Sciences of Limnology and Oceanography, 2005, 50 (5), pp.1459-1472. 〈hal-00688046〉
  • Karine Leblanc, Bernard Queguiner, Patrick Raimbault, Nicole Garcia. Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea. Biogeosciences, European Geosciences Union, 2005, 2, pp.219-229. 〈hal-00688018〉
  • Anne Maixandeau, Dominique Lefèvre, Hera Karayanni, Urania Christaki, France Van Wambeke, et al.. Microbial community production, respiration and structure of the microbial food web of an ecosystem in the northeastern Atlantic Ocean. Journal of Geophysical Research, American Geophysical Union, 2005, 110, pp.C07S17 -13. 〈hal-00092669〉
  • Karine Leblanc, Bernard Quéguiner, L. Prieur, H. Claustre, K. Oubelkheir, et al.. Siliceous phytoplankton production and export related to trans-frontal dynamics of the Almeria-Oran frontal system (western Mediterranean Sea) during winter. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2004, 109, pp.C07010. 〈10.1029/2003JC001878〉. 〈hal-00702535〉
  • Stéphane Blain, Cécile Guieu, Hervé Claustre, Karine Leblanc, T. Moutin, et al.. Availability of iron and major nutrients for phytoplankton in the northeast Atlantic Ocean. Limnology and Oceanography, Association for the Sciences of Limnology and Oceanography, 2004, 49 (6), pp.2095-2104. 〈10.4319/lo.2004.49.6.2095〉. 〈hal-00702539〉
  • Karine Leblanc, Bernard Quéguiner, Nicole Garcia, Peggy Rimmelin, Patrick Raimbault. Silicon cycle in the Northwestern Mediterranean Sea: seasonal study of a coastal oligotrophic site.. Oceanologica Acta, Elsevier, 2003, 26 (4), pp.339-355. 〈10.1016/S0399-1784(03)00035-5〉. 〈hal-00700111〉
  • Michel Fiala, B. Delille, Catherine-Marie Dubreuil, E. Kopcynska, Karine Leblanc, et al.. Mesoscale surface distribution of biogeochemical characteristics associated with a frontal system in the Crozet Basin during austral summer 1999.. Marine Ecology Progress Series, Inter Research, 2003, 249, pp.1-14. 〈10.3354/meps249001〉. 〈hal-00700116〉
  • Hervé Claustre, A. Morel, S.B. Hooker,, M. Babin, D. Antoine, et al.. Is desert dust making oligotrophic waters greener?. Geophysical Research Letters, American Geophysical Union, 2002, 29 (10), pp.107. 〈10.1029/2001GL014056〉. 〈hal-00702800〉
  • Karine Leblanc, Bernard Quéguiner, Michel Fiala, Stéphane Blain, J. Morvan. Particulate biogenic silica and carbon production rates and particulate matter distribution in the Indian sector of the Subantarctic Ocean. Deep Sea Research Part II: Topical Studies in Oceanography, Elsevier, 2002, 49 (16), pp.3189-3206. 〈10.1016/S0967-0645(02)00078-4〉. 〈hal-00700118〉

Thèse1 document

  • Karine Leblanc. Variabilité spatiale et temporelle du cycle du silicium dans divers milieux oligotrophes et mésotrophes. Océanographie. Université de la Méditerranée – Aix-Marseille II, 2002. Français. 〈tel-01783412〉