Aarhus University Seal / Aarhus Universitets segl

Development, Productivity, and Seasonality of Living Planktonic Foraminiferal Faunas and Limacina helicina in an Area of Intense Methane Seepage in the Barents Sea

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

DOI

  • Siri Ofstad, UiT The Arctic University of Norway
  • ,
  • Julie Meilland, University of Bremen
  • ,
  • Katarzyna Zamelczyk, UiT The Arctic University of Norway, Norwegian Polar Institute
  • ,
  • Melissa Chierici, Institute of Marine Research
  • ,
  • Agneta Fransson, Norwegian Polar Institute
  • ,
  • Friederike Gründger
  • Tine L. Rasmussen

Although the plankton communities in the Barents Sea have been intensely studied for decades, little is known about the living planktonic foraminiferal (LPF) and pteropod faunas, especially those found at methane seep sites. Along a repeated transect in the “crater area” (northern Barents Sea, 74.9°N, 27.7°E) in spring and summer 2016 the flux of LPF and of the pteropod species Limacina helicina showed a high degree of variability. The LPF had low concentration (0–6 individuals m−3) and small tests (x̄ = 103.3 μm) in spring and a 53-fold increase (43–436 individuals m−3) and larger tests (x̄ = 188.6 μm) in summer. Similarly, the concentration of L. helicina showed a tenfold increase between spring and summer. The LPF species composition remained stable with the exception of the appearance of subtropical species in summer. No relationship was observed between the spatial distribution of LPF, L. helicina, and methane concentrations in the area. The methane plumes in April coincided with elevated dissolved inorganic carbon, low pH, and calcium carbonate saturation states, and the methane concentration seemed to be controlled by lateral advection. The δ13C and δ18O of Neogloboquadrina pachyderma and Turborotalita quinqueloba are comparable to previous observations in the Arctic and do not show any influence of methane in the isotopic signals of the shells. Although no evidence of direct impact of high methane concentrations on the LPF (size and concentration) were found, we speculate that methane could indirectly enhance primary productivity, and thus biomass, through several potential pathways.

OriginalsprogEngelsk
Artikelnummere2019JG005387
TidsskriftJournal of Geophysical Research: Biogeosciences
Vol/bind125
Nummer2
ISSN2169-8953
DOI
StatusUdgivet - feb. 2020

Se relationer på Aarhus Universitet Citationsformater

ID: 182445353