• Biogeochemical Consequences of Nonvertical Methane Transport in Sediment Offshore Northwestern Svalbard 

      Treude, Tina; Krause, Stefan; Steinle, Lea; Burwicz, Ewa B.; Hamdan, L.J.; Niemann, Helge; Feseker, Tomas; Liebetrau, Volker; Krastel, Sebastian; Berndt, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-21)
      A site at the gas hydrate stability limit was investigated offshore northwestern Svalbard to study methane transport in sediment. The site was characterized by chemosynthetic communities (sulfur bacteria mats, tubeworms) and gas venting. Sediments were sampled with in situ porewater collectors and by gravity coring followed by analyses of porewater constituents, sediment and carbonate geochemistry, ...
    • Effects of low oxygen concentrations on aerobic methane oxidation in seasonally hypoxic coastal waters 

      Steinle, Lea; Maltby, Johanna; Treude, Tina; Kock, Annette; Bange, Hermann W.; Engbersen, Nadine; Zopfi, Jakob; Lehmann, Moritz F.; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-29)
      Coastal seas may account for more than 75 % of global oceanic methane emissions. There, methane is mainly produced microbially in anoxic sediments from which it can escape to the overlying water column. Aerobic methane oxidation (MOx) in the water column acts as a biological filter, reducing the amount of methane that eventually evades to the atmosphere. The efficiency of the MOx filter is potentially ...
    • Life on the edge: Active microbial communities in the Kryos MgCl2-brine basin at very low water activity 

      Steinle, Lea; Knittel, Katrin; Felber, Nicole; Casalino, Claudia; de Lange, Gert; Tessarolo, Chiara; Stadnitskaia, Alina; Sinninghe Damsté, Jaap S.; Zopfi, Jakob; Lehmann, Moritz F.; Treude, Tina (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-17)
      The Kryos Basin is a deep-sea hypersaline anoxic basin (DHAB) located in the Eastern Mediterranean Sea (34.98°N 22.04°E). It is filled with brine of re-dissolved Messinian evaporites and is nearly saturated with MgCl<sub>2</sub>-equivalents, which makes this habitat extremely challenging for life. The strong density difference between the anoxic brine and the overlying oxic Mediterranean seawater ...
    • Manganese/iron‐supported sulfate‐dependent anaerobic oxidation of methane by archaea in lake sediments 

      Su, Guangyi; Zopfi, Jakob; Yao, Haoyi; Steinle, Lea; Niemann, Helge; Lehmann, Moritz F (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-04)
      Anaerobic oxidation of methane (AOM) by methanotrophic archaea is an important sink of this greenhouse gas in marine sediments. However, evidence for AOM in freshwater habitats is rare, and little is known about the pathways, electron acceptors, and microbes involved. Here, we show that AOM occurs in anoxic sediments of a sulfate‐rich lake in southern Switzerland (Lake Cadagno). Combined AOM‐rate ...
    • Temporal constraints on hydrate-controlled methane seepage off Svalbard 

      Berndt, Christian; Feseker, Tomas; Treude, Tina; Krastel, Sebastien; Liebetrau, Volker; Niemann, Helge; Bertics, Victoria; Dumke, Ines; Dünnbier, Karolin; Ferré, Benedicte; Graves, Carolyn; Gross, Felix; Hissmann, Karen; Hühnerbach, Veit; Krause, Stefan; Lieser, Kathrin; Schauer, Jürgen; Steinle, Lea (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-17)
      Methane hydrate is an icelike substance that is stable at high pressure and low temperature in continental margin sediments. Since the discovery of a large number of gas flares at the landward termination of the gas hydrate stability zone off Svalbard, there has been concern that warming bottom waters have started to dissociate large amounts of gas hydrate and that the resulting methane release may ...
    • Water column methanotrophy controlled by a rapid oceanographic switch 

      Steinle, Lea; Graves, Carolyn A.; Treude, Tina; Ferré, Benedicte; Biastoch, Arne; Bussmann, Ingeborg; Berndt, Christian; Krastel, Sebastian; James, Rachel H.; Behrens, Erik; Böning, Claus W.; Greinert, Jens; Sapart, Célia-Julia; Scheinert, Markus; Sommer, Stefan; Lehmann, Moritz F.; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-20)
      Large amounts of the greenhouse gas methane are released from the seabed to the water column, where it may be consumed by aerobic methanotrophic bacteria. The size and activity of methanotrophic communities, which determine the amount of methane consumed in the water column, are thought to be mainly controlled by nutrient and redox dynamics. Here, we report repeated measurements of methanotrophic ...