I am a postdoctoral researcher at Université de Bretagne Occidentale working on the determination of carbon and nitrogen fluxes at the the plankton population level.

I defended my Ph.D. thesis in December 2015 at Aix Marseille University in France. I investigated the influence of nitrogen inputs mediated by diazotrophs in on the plankton population dynamics and on nitrogen and carbon cycles in surface oceans. I contributed to  develop an innovative method to measure the carbon and nitrogen uptake at the single cell level in complex planktonic assemblages. For this purpose, we coupled isotope labeling incubations, flow cytometry cell sorting and nanoscale secondary ion mass spectrometry (nanoSIMS). I am now using these tools to measure the relative importance of the various sources of nitrogen available in the ocean for the different natural phytoplankton populations. Results from this project will give useful insights on key players of the particulate export in the ocean.

Besides science, I spend most of my time riding my bike to get to climbing spots.

Peer-reviewed publications

  1. Berthelot H., Moutin, S. L’Helguen, K. Leblanc, S. Hélias, O. Grosso, N. Leblond, B. Charrière, and S. Bonnet. Dinitrogen fixation and dissolved organic nitrogen fueled primary production and particulate export during the VAHINE mesocosms experiment (New Caledonia lagoon). Biogeosciences. 2015.
  2. Berthelot H., Bonnet, M. Camps, O. Grosso and T. Moutin. Assessment of the dinitrogen released as ammonium and dissolved organic nitrogen by unicellular and filamentous marine diazotrophic cyanobacteria grown in culture. Front. Mar. Sci. – Marine Biogeochemistry. 2015.
  3. Benavides M., P. H. Moisander, H. Berthelot, T. Dittmar, O. Grosso, S. Bonnet. Mesopelagic heterotrophic N2 fixation related to organic matter composition in the Solomon and Bismarck Seas (Southwest Pacific). PLOSone. 2015.
  4. Bonnet S., H. Berthelot, K. Turk-Kubo, S. Fawcett, S. L’Helguen, J. P. Zehr. Dynamics of N2 fixation and fate of diazotroph-derived nitrogen during the VAHINE mesocosm experiment. Biogeosciences. 2016.
  5. Hunt B. P. V., S. Bonnet, H. Berthelot, B. J. Conroy, R. Foster, M. Pagano. Contribution and pathways of diazotroph derived nitrogen to zooplankton during the VAHINE mesocosm experiment in the oligotrophic New Caledonia lagoon. Biogeosciences. 2016.
  6. Van Wanbeke F., U. Pfreundt, A. Barani, H. Berthelot, T. Moutin, M Rodier, W. Heiss, S Bonnet. Dynamics of heterotrophic bacterial community during an experimental diazotrophic bloom in New Caledonia and links with bacterial diversity – the VAHINE experiment. Biogeosciences. 2016.
  7. Bonnet S., H. Berthelot, K. Turk-Kubo, V. Cornet-Barthaux, S. Fawcett, I. Berman-Frank, A. Barani, J. Dekaezemacker, M. Benavides, B. Charrière, and D. G. Capone. Diazotroph derived nitrogen supports diatoms growth in the South West Pacific: a quantitative study using nanoSIMS. Limnology and Oceanography. 2016.
  8. Berthelot H., Bonnet, O. Grosso, V. Cornet. Diazotroph Derived Nitrogen fixed by Trichodesmium, Crocosphaera watsonii and Cyanothece and transfer towards the planktonic community: a comparative study. Biogeosciences. 2016.
  9. Spungin, U. Pfreundt, H. Berthelot, S. Bonnet, D. AlRoumi, F. Natale, W.R. Hess, K.D. Bidle, and I. Berman-Frank. Mechanisms of Trichodesmium bloom demise within the New Caledonia Lagoon. Biogeosciences. 2016.
  10. Bonnet S., M. Baklouti, A. Gimenez, H. Berthelot, I. Berman-Frank. Biogeochemical and biological impacts of diazotroph blooms in a Low Nutrient Low Chlorophyll ecosystem: synthesis from the VAHINE mesocosm experiment (New Caledonia). Biogeosciences. 2016.
  11. Leblanc K., V. Cornet, M. Caffin, M. Rodier, A. Desnues, H. Berthelot, K. Turk-Kubo, and J. Heliou. Phytoplankton community structure in the VAHINE mesocosm experiment Biogeosciences. 2016.
  12. Benavides M., H. Berthelot, S. Duhamel, P. Raimbault, S. Bonnet. Dissolved organic matter uptake by Trichodesmium in the Southwest Pacific (in revision).
  13. Ganachaud A., S. Cravatte, J. Sprintall, C. Germineaud, M. Alberty, C. Jeandel, G. Eldin, M. Benavides, S. Bonnet, L. E. Heimburger, J. Lefèvre, N. Metzl, S. Michael, J. Resing, F. Quéroué, G. Sarthou, M. Rodier, H. Berthelot, F. Baurand, J. Grelet, T. Hasegawa, W. Kessler, M. Kilepak, F. Lacan, E. Privat, U. Send, P. Van Beek, M. Souhaut, E. S. Jeroen. Two oceanographic cruises explore the Solomon Sea circulation, chemistry, geochemistry and biology (submitted).