Research Interests

​My research aims at understanding the cycling and transport of organic matter in the marine environment, in particular deciphering its changes in quantity, quality and reactivity. I have a particular interest in identifying the imprint of biological communities and processes on the chemical composition of organic compounds and how these compounds in-turn influence microbial and phytoplankton ecology.

Selected Publications

  • Major hydrogeochemical processes in an Acid Mine Drainage affected estuary
    M. P. Asta, M. Ll. Calleja, R. Pérez-López, L. F. Auqué
    Marine Pollution Bulletin, Volume 91: 295-305, (2015)
  • Ocean-atmosphere exchange of organic carbon and CO2 surrounding the Antarctic Peninsula
    S. R. Ruiz-Halpern, M. Ll. Calleja, J. Dachs, S. Del Vento, M. Pastor, M. Palmer, S. Agust...
    Biogeosciences, Volume 11: 2755-2770, (2014)
  • Prevalence of strong vertical CO2 and O2 variability in the top meters of the ocean
    M. Ll. Calleja, C.M. Duarte, M. Álvarez, R. Vaquer-Sunyer, S. Agustí, G. J. Herndl
    Global Biogeochemical Cycles, Volume 27: 1-9, (2013)
  • Changes in compound specific δ15N amino acid signatures and D/L ratios in marine dissolved organic matter induced b...
    M. Ll. Calleja, F. Batista, M. Peacock, R. Kudela, M. D. McCarthy
    Marine Chemistry, Volume 149: 32-44, (2013)
  • Mesopelagic prokaryotic bulk and single-cell heterotrophic activity and community composition in the NW Africa-Cana...
    J. M. Gasol, L. Alonso-Sáez, D. Vaqué, F. Baltar, M. Ll. Calleja, C. M. Duarte, J. Arísteg...
    Progress in Oceanography, Special Issue on EBUS, Progress in Oceanography, Volum..., (2009)
  • Evidence for surface organic matter modulation of air-sea CO2 exchange
    M. Ll. Calleja, C.M. Duarte, Y.T. Priarie, S.Agustí, G.J. Herndl
    Biogeosciences, Volume 6, 1105-1114, (2009)
  • The relationship between seagrass (Posidonia oceanica) decline and sulfide porewater concentration in carbonate sed...
    M. Ll. Calleja, N. Marbà, C.M. Duarte
    Estuarine Coastal and Shelf Science, Volume 73:583-588, (2007)
  • Light regulation of benthic sulfate reduction rates mediated by seagrass (Thalassia testudinum) metabolism
    M. Ll. Calleja, C. Barrón, J.A. Hale, T.K. Frazer, C.M. Duarte
    Estuaries and Coasts, Volume 29, Issue 6B, 1255-1264, (2006)
  • High atmosphere-ocean exchange of organic carbon in the NE subtropical Atlantic
    J. Dachs, M. Ll Calleja, C. M.Duarte, S. del Vento, B. Turpin, A. Polidori, G.J. Herndl, ...
    Geophysical Research Letters. Volume 32, L21807, (2005)
  • Control of air-sea CO2 disequilibria in the subtropical NE Atlantic by planktonic metabolism under the ocean skin
    M. Ll. Calleja, C.M. Duarte, N. Navarro, S. Agustí
    Geophysical Research Letters. Volume 32, L08606, (2005)

Education Profile

  • ​Ph.D., Marine Sciences, Universitat de les Illes Balears, Palma de Mallorca, Spain, 2007
  • B.Sc., Chemistry, Universidad de Barcelona, Barcelona, Spain, 1999

Professional Profile

  • ​2015-present: Postdoctoral Researcher, KAUST, Thuwal, Saudi Arabia
  • 2011-2014: Postdoctoral Researcher, Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
  • 2008-2010: Postdoctoral Fellow, University of California Santa Cruz (UCSC), California, USA, 2008-2010

Scientific and Professional Memberships

  • ​American Society of Limnology and Oceanography (ASLO)


  • ​Young Investigator Award, ISOCOMPOUND'09 European Science Foundation (ESF) and National Science Foundation (NSF) Networks, Potsdam, Germany, 2009

KAUST Affiliations

  • ​Red Sea Research Center (RSRC)
  • Division of Biological and Environmental Science and Engineering (BESE)