Cristin-resultat-ID: 1567870
Sist endret: 22. februar 2018 00:00

New Insights into Methane Driven Dissolved Organic Matter Dynamics in the Arctic Ocean

  • Muhammed Fatih Sert
  • Anna Silyakova
  • Friederike Gründger
  • Juliana D' Andrilli
  • Helge Niemann
  • Alexey K. Pavlov
  • mfl.


Om resultatet



  • Engelsk


New Insights into Methane Driven Dissolved Organic Matter Dynamics in the Arctic Ocean


Dissociated hydrates and gas bearing sediment release methane into the water column through a large number of shallow water seeps in the Arctic Ocean. The liberated methane dissolves and can lead to areas with high bottom water methane concentrations which fosters growth of aerobic methane oxidizing bacteria (MOB) that metabolize methane as a source of carbon and energy. As a result of their metabolic activity, MOB release organic intermediates and cell lysis products, contributing to the dissolved organic matter (DOM) pool in the water column. Considering the massive flux of methane and elevated rates of microbial oxidation, methane driven DOM contribution may constitute an important control on the water column biochemistry and food web structure at the active seep sites. We have collected sea water samples from well-characterized seep areas during two research expeditions at the western shelf of Svalbard and in the Barents Sea in summer 2017. We performed analyses of dissolved nutrients, methane, organic carbon, chlorophyll-a, and particulate organic matter in order to investigate the influence of methane seepage on water column biogeochemistry. DOM will be characterized by fluorescence (excitation-emission matrices) of colored-DOM and its chemical composition at the molecular level using ultrahigh resolution mass spectrometry (FT-ICR-MS). We hypothesize that MOB processes may alter the composition of DOM towards more labile and heterogeneous formulae which in turn could promote microbial activity and stimulate primary production by providing energetic carbon substrates to the water column. This study is funded by CAGE (Centre for Arctic Gas Hydrate, Environment and Climate), Norwegian Research Council grant no. 223259.