• Accounting for Uncertainties in Biodiversity Estimations: A New Methodology and Its Application to the Mesopelagic Sound Scattering Layer of the High Arctic 

      Herrmann, Bent; Cerbule, Kristine; Brčić, Jure; Grimaldo Vela, Eduardo Enrique; Geoffroy, Maxime; Daase, Malin; Berge, Jørgen (Peer reviewed; Journal article, 2022)
      Measures of biological diversity (biodiversity) are important for monitoring the state of ecosystems. Several indices and methods are used to describe biodiversity from field observations. Marine faunal biodiversity is ...
    • Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth 

      Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.; Johnsen, Geir; McKee, David; Kostakis, I; Renaud, Paul E.; Vogedes, Daniel Ludwig; Anderson, Philip J.; Last, Kim; Gauthier, Stephane (Peer reviewed; Journal article, 2020)
      For organisms that remain active in one of the last undisturbed and pristine dark environments on the planet—the Arctic Polar Night—the moon, stars and aurora borealis may provide important cues to guide distribution and ...
    • Eat or sleep: Availability of winter prey explains mid-winter and spring activity in an Arctic Calanus population 

      Hobbs, Laura; Banas, Neil S.; Cottier, Finlo Robert; Berge, Jørgen; Daase, Malin (Peer reviewed; Journal article, 2020)
      Copepods of the genus Calanus have adapted to high levels of seasonality in prey availability by entering a period of hibernation during winter known as diapause, but repeated observations of active Calanus spp. have been ...
    • In the dark: a review of ecosystem processes during the Arctic polar night 

      Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.; Johnsen, Geir; Seuthe, Lena; Weslawski, Jan Marcin; Leu, Eva; Moline, Mark A.; Nahrgang, Jasmine; Søreide, Janne; Varpe, Øystein; Lønne, Ole Jørgen; Daase, Malin; Falk-Petersen, Stig (Journal article, 2015)
      Several recent lines of evidence indicate that the polar night is key to understanding Arctic marine ecosystems. First, the polar night is not a period void of biological activity even though primary production is close ...
    • Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton? 

      Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig; Renaud, Paul; Leu, Eva; Grenvald, Julie Cornelius; Cottier, Finlo; Cronin, Heather; Menze, Sebastian; Norgren, Petter; Varpe, Øystein; Daase, Malin; Darnis, Gérald; Johnsen, Geir (Journal article, 2015)
      The light regime is an ecologically important factor in pelagic habitats, influencing a range of biological processes. However, the availability and importance of light to these processes in high Arctic zooplankton communities ...
    • Pelagic occurrences of the ice amphipod Apherusa glacialis throughout the Arctic 

      Kunisch, Erin; Bluhm, Bodil; Daase, Malin; Gradinger, Rolf; Hop, Haakon; Melnikov, Igor A.; Øystein, Varpe; Berge, Jørgen (Journal article; Peer reviewed, 2020)
      Apherusa glacialis is a common, sea ice-associated amphipod found throughout the Arctic Ocean and has long been considered permanently associated with the sea ice habitat. However, pelagic occurrences of A. glacialis have ...
    • Pelagic organisms avoid white, blue, and red artificial light from scientific instruments 

      Geoffroy, Maxime; Langbehn, Tom; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.; Berge, Jørgen (Journal article; Peer reviewed, 2021)
      In situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. ...
    • Photoperiodism and overwintering in boreal and sub-Arctic Calanus finmarchicus populations 

      Coguiec, Estelle; Last, Kim S.; Cohen, Jonathan H.; Hobbs, Laura; Choquet, Marvin; Ershova, Elizaveta; Berge, Jørgen; Daase, Malin (Journal article, 2023)
      ABSTRACT: The copepod Calanus finmarchicus, a key species in the North Atlantic, generally spends the non-productive season by descending into deep waters and entering diapause, a physiological state characterized by reduced ...
    • Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night 

      Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura; Johnsen, Geir; Berge, Jørgen (Peer reviewed; Journal article, 2021)
      Light plays a fundamental role in the ecology of organisms in nearly all habitats on Earth and is central for processes such as vision and the entrainment of the circadian clock. The poles represent extreme light regimes ...
    • Seasonal Variability in the Zooplankton Community Structure in a Sub-Arctic Fjord as Revealed by Morphological and Molecular Approaches 

      Coguiec, Estelle; Ershova, Elizaveta; Daase, Malin; Vonnahme, Tobias R.; Wangensteen, Owen S.; Gradinger, Rolf; Præbel, Kim; Berge, Jørgen (Peer reviewed; Journal article, 2021)
      Phyto- and zooplankton in Arctic and sub-Arctic seas show very strong seasonal changes in diversity and biomass. Here we document the seasonal variability in the mesozooplankton community structure in a sub-Arctic fjord ...
    • Use of an Autonomous Surface Vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance 

      Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær; Singh, Hanumant; Sørensen, Asgeir Johan; Daase, Malin; Johnsen, Geir (Journal article; Peer reviewed, 2018)
      Light is a major cue for nearly all life on Earth. However, most of our knowledge concerning the importance of light is based on organisms’ response to light during daytime, including the dusk and dawn phase. When it is ...