• Compositions of dissolved organic matter in the ice-covered waters above the Aurora hydrothermal vent system, Gakkel Ridge, Arctic Ocean 

      Sert, Muhammed Fatih; Niemann, Helge; Reeves, Eoghan; Granskog, Mats A.; Hand, Kevin P.; Kekäläinen, Timo; Jänis, Janne; Rossel, Pamela; Ferré, Benedicte; Silyakova, Anna; Gründger, Friederike (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-20)
      Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contribution to the oceanic DOM pool may be substantial. ...
    • Elevated methane alters dissolved organic matter composition in the Arctic Ocean cold seeps 

      Sert, Muhammed Fatih; Schweitzer, Hannah; de Groot, Tim R.; Kekäläinen, Timo; Jänis, Janne; Bernstein, Hans Christopher; Ferré, Benedicte; Gründger, Friederike; Kalenitchenko, Dimitri Stanislas Desire; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-15)
      Cold seeps release methane (CH<sub>4</sub>) from the seafloor to the water column, which fuels microbially mediated aerobic methane oxidation (MOx). Methane-oxidising bacteria (MOB) utilise excess methane, and the MOB biomass serves as a carbon source in the food web. Yet, it remains unclear if and how MOx modifies the composition of dissolved organic matter (DOM) in cold seeps. We investigated MOx ...