Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 7, issue 3
Biogeosciences, 7, 1099-1108, 2010
https://doi.org/10.5194/bg-7-1099-2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 7, 1099-1108, 2010
https://doi.org/10.5194/bg-7-1099-2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.

  19 Mar 2010

19 Mar 2010

Methane production in aerobic oligotrophic surface water in the central Arctic Ocean

E. Damm1, E. Helmke1, S. Thoms1, U. Schauer1, E. Nöthig1, K. Bakker2, and R. P. Kiene3,4 E. Damm et al.
  • 1Alfred Wegener Institute for Polar and Marine Research, P.O. Box 12061, 27515 Bremerhaven, Germany
  • 2Royal Netherlands Institute for Sea Research, Texel, The Netherlands
  • 3Department of Marine Sciences, University of South Alabama, Mobile, Alabama, USA
  • 4Dauphin Island Sea Lab, Dauphin Island, Alabama, USA

Abstract. A methane surplus relative to the atmospheric equilibrium is a frequently observed feature of ocean surface water. Despite the common fact that biological processes are responsible for its origin, the formation of methane in aerobic surface water is still poorly understood. We report on methane production in the central Arctic Ocean, which was exclusively detected in Pacific derived water but not nearby in Atlantic derived water. The two water masses are distinguished by their different nitrate to phosphate ratios. We show that methane production occurs if nitrate is depleted but phosphate is available as a P source. Apparently the low N:P ratio enhances the ability of bacteria to compete for phosphate while the phytoplankton metabolite dimethylsulfoniopropionate (DMSP) is utilized as a C source. This was verified by experimentally induced methane production in DMSP spiked Arctic sea water. Accordingly we propose that methylated compounds may serve as precursors for methane and thermodynamic calculations show that methylotrophic methanogenesis can provide energy in aerobic environments.

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