• Benthic communities at high-Arctic cold seeps: Faunal response to methane seepage in Svalbard 

      Åström, Emmelie (Doctoral thesis; Doktorgradsavhandling, 2018-03-20)
      Cold seeps are chemosynthetic habitats found in both deep sea and shallow ocean-shelves worldwide, including the polar regions. At seeps, hydrocarbons, sulfide, and other reduced compounds emerge from the seafloor, providing energy to fuel chemoautotrophic production. Microbial assemblages, supported by the oxidation and reduction of gases and fluids, form the base of a food web composing unique and ...
    • Bivalve shell horizons in seafloor pockmarks of the last glacial-interglacial transition suggest a thousand years of methane emissions in the Arctic Ocean 

      Ambrose, William; Panieri, Giuliana; Schneider, Andrea; Plaza-Faverola, Andreia; Carroll, Michael Leslie; Åström, Emmelie; Locke, W.L.; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-05)
      We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (1200 m water depth) and western Svalbard (798000 N, 068550 W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at ...
    • CASCADE-The Circum-Arctic Sediment CArbon DatabasE 

      Martens, Jannik; Romankevich, Evgeny; Semiletov, Igor; Wild, Birgit; Van Dongen, Bart; Vonk, Jorien; Tesi, Tommaso; Shakhova, Natalia; Dudarev, Oleg V.; Kosmach, Denis; Vetrov, Alexander; Lobkovsky, Leopold; Belyaev, Nikolay; Macdonald, Robie W.; Pieńkowski, Anna J.; Eglinton, Timothy I.; Haghipour, Negar; Dahle, Salve; Carroll, Michael L.; Åström, Emmelie; Grebmeier, Jacqueline M.; Cooper, Lee W.; Possnert, Göran; Gustafsson, Örjan (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-08)
      Biogeochemical cycling in the semi-enclosed Arctic Ocean is strongly influenced by land–ocean transport of carbon and other elements and is vulnerable to environmental and climate changes. Sediments of the Arctic Ocean are an important part of biogeochemical cycling in the Arctic and provide the opportunity to study present and historical input and the fate of organic matter (e.g., through permafrost ...
    • Chemosynthesis influences food web and community structure in high-Arctic benthos 

      Åström, Emmelie; Carroll, Michael; Sen, Arunima; Niemann, Helge; Ambrose Jr., William G.; Lehmann, Moritz F; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-25)
      Cold seeps are locations where seafloor communities are influenced by the seepage of methane and other reduced compounds from the seabed. We examined macro-infaunal benthos through community analysis and trophic structure using stable isotope analysis at 3 seep locations in the Barents Sea. These seeps were characterized by high densities of the chemosymbiotic polychaetes Siboglinidae, clade Frenulata ...
    • Chemosynthetic and photosynthetic trophic support from cold seeps in Arctic benthic communities 

      Åström, Emmelie; Bluhm, Bodil; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-17)
      Benthic communities below the photic zone are largely reliant on the export of surface-water primary production and the flux of partially degraded organic matter to the seabed, i.e. pelagic−benthic coupling. Over the past decades, however, the role of chemosynthetically produced carbon in food webs has been recognized in various habitats. Cold seeps are now known to be widespread across circumpolar ...
    • Cold Seeps in a Warming Arctic: Insights for Benthic Ecology 

      Åström, Emmelie; Sen, Arunima; Carroll, Michael Leslie; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-21)
      Cold-seep benthic communities in the Arctic exist at the nexus of two extreme environments; one reflecting the harsh physical extremes of the Arctic environment and another reflecting the chemical extremes and strong environmental gradients associated with seafloor seepage of methane and toxic sulfide-enriched sediments. Recent ecological investigations of cold seeps at numerous locations on the ...
    • Methane cold seeps as biological oases in the high-Arctic deep sea 

      Åström, Emmelie; Carroll, Michael Leslie; Ambrose, William; Sen, Arunima; Silyakova, Anna; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-27)
      Cold seeps can support unique faunal communities via chemosynthetic interactions fueled by seabed emissions of hydrocarbons. Additionally, cold seeps can enhance habitat complexity at the deep seafloor through the accretion of methane derived authigenic carbonates (MDAC). We examined infaunal and megafaunal community structure at high-Arctic cold seeps through analyses of benthic samples and ...
    • A new genus and two new species of Thyasiridae associated with methane seeps off Svalbard, Arctic Ocean 

      Åström, Emmelie; Oliver, Graham; Carroll, Michael Leslie (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-16)
      Bivalves have been found in unique benthic assemblages associated with active methane seeps and mounds along the western and southern margins of the Svalbard shelf (75–79°N) at 350–380 m depth. Among the samples collected were a number of shells of Thyasiridae that are distinct from any species previously described. Here we describe one new genus Rhacothyas gen. nov. and two new species Thyasira ...
    • New Late Pleistocene species of Acharax from Arctic methane seeps off Svalbard 

      Hansen, Jesper; Ezat, Mohamed; Åström, Emmelie; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-01)
      We report, for the first time, the solemyid <i>Acharax svalbardensis</i> sp. nov., from deep-sea methane seep sites on the western Svalbard margin, 79°N. This species is rather small and so far the northernmost representative of its genus. It is identified based on the following combination of diagnostic characters: umbo 27–30% valve length from posterior margin; H/L ratio ∼0.35; broadly rounded to ...