• Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current from Rijpfjorden, Svalbard, to the Arctic Ocean during Summer (2010-2014) 

      Hop, Haakon; Assmy, Philipp; Wold, Anette; Sundfjord, Arild; Daase, Malin; Duarte, Pedro; Kwasniewski, Slawomir; Gluchowska, Marta; Wiktor, Józef Maria; Tatarek, Agnieszka; Wiktor, Józef Maria Jr.; Kristiansen, Svein; Fransson, Agneta Ingrid; Chierici, Melissa; Vihtakari, Mikko (Journal article; Peer reviewed, 2019-04-09)
      The northern coast of Svalbard contains high-arctic fjords, such as Rijpfjorden (80°N 22°30′E). This area has experienced higher sea and air temperatures and less sea ice in recent years, and models predict increasing temperatures in this region. Part of the West Spitsbergen Current (WSC), which transports relatively warm Atlantic water along the continental slope west of Svalbard, bypasses these ...
    • Pelagic food-webs in a changing Arctic: a trait-based perspective suggests a mode of resilience 

      Renaud, Paul Eric; Daase, Malin; Banas, Neil; Gabrielsen, Tove M.; Søreide, Janne; Varpe, Øystein; Cottier, Finlo Robert; Falk-Petersen, Stig; Halsband, Claudia; Vogedes, Daniel Ludwig; Heggland, Kristin; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-27)
      Arctic marine ecosystems support fisheries of significant and increasing economic and nutritional value. Commercial stocks are sustained by pelagic food webs with relatively few keystone taxa mediating energy transfer to higher trophic levels, and it remains largely unknown how these taxa will be affected by changing climate and the influx of boreal taxa. <i>Calanus</i> species store large quantities ...
    • Pelagic occurrences of the ice amphipod Apherusa glacialis throughout the Arctic 

      Kunisch, Erin; Bluhm, Bodil; Daase, Malin; Gradinger, Rolf; Hop, Haakon; Melnikov, Igor A.; Varpe, Øystein; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-10)
      <i>Apherusa glacialis</i> 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 <i>A. glacialis</i> have also been reported. It was recently suggested that <i>A. glacialis</i> overwinters at depth within the Atlantic-water inflow near Svalbard, to avoid being exported ...
    • 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; Tidsskriftartikkel; Peer reviewed, 2020-01-10)
      <i>Apherusa glacialis</i> 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 <i>A. glacialis</i> have also been reported. It was recently suggested that <i>A. glacialis</i> overwinters at depth within the Atlantic-water inflow near Svalbard, to avoid being exported ...
    • 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; Tidsskriftartikkel; Peer reviewed, 2021-07-22)
      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. It is often assumed that most pelagic organisms do not perceive the red part of the visible spectrum and that red light can be used for underwater optical measurements of biological ...
    • 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; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      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 metabolism and arrested development. In the open ocean, overwintering depths are below 600 m, where temperature and light conditions are favourable to initiate diapause. However, C. ...
    • 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 (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-19)
      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 with an annual light cycle including periods of Midnight Sun and Polar Night. The Arctic Ocean extends to the North Pole, and marine light extremes reach their maximum extent in ...
    • Remote sensing of zooplankton swarms 

      Basedow, Sünnje Linnéa; McKee, David; Lefering, Ina; Gislason, Astthor; Daase, Malin; Trudnowska, Emilia; Egeland, Einar Skarstad; Choquet, Marvin; Falk-Petersen, Stig (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-24)
      Zooplankton provide the key link between primary production and higher levels of the marine food web and they play an important role in mediating carbon sequestration in the ocean. All commercially harvested fish species depend on zooplankton populations. However, spatio-temporal distributions of zooplankton are notoriously difficult to quantify from ships. We know that zooplankton can form large ...
    • Retention of ice-associated amphipods: possible consequences for an ice-free Arctic Ocean 

      Berge, Jørgen; Varpe, Øystein; Moline, Mark A.; Wold, A; Renaud, Paul; Daase, Malin; Falk-Petersen, Stig (Journal article; Tidsskriftartikkel; Peer reviewed, 2012-09-12)
      Recent studies predict that the Arctic Ocean will have ice-free summers within the next 30 years. This poses a significant challenge for the marine organisms associated with the Arctic sea ice, such as marine mammals and, not least, the iceassociated crustaceans generally considered to spend their entire life on the underside of the Arctic sea ice. Based upon unique samples collected within ...
    • Seasonal and diel vertical migration of zooplankton in the High Arctic during the autumn midnight sun of 2008 

      Rabindranath, Ananda; Daase, Malin; Falk-Petersen, Stig; Wold, Anette; Wallace, M.I.; Berge, Jørgen; Brierley, A. S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      The diel vertical migration (DVM) of Calanus (Calanus finmarchicus, Calanus glacialis and Calanus hyperboreus) and Metridia longa was investigated in August 2008 at six locations to the north and northwest of Svalbard (Rijpfjorden, Ice, Marginal Ice Zone, Shelf break, Shelf and Kongsfjorden). Despite midnight sun conditions, a diel light cycle was clearly observed at all stations. We collected data ...
    • Seasonal ecology in ice-covered Arctic seas - Considerations for spill response decision making 

      Aune, Magnus; Aniceto, Ana Sofia; Biuw, Martin; Daase, Malin; Falk-Petersen, Stig; Leu, Eva; Ottesen, Camilla; Sagerup, Kjetil; Camus, Lionel (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-05)
      Due to retreating sea ice and predictions of undiscovered oil and gas resources, increased activity in Arctic shelf sea areas associated with shipping and oil and gas exploration is expected. Such activities may accidentally lead to oil spills in partly ice-covered ocean areas, which raises issues related to oil spill response. Net Environmental Benefit Analysis (NEBA) is the process that the response ...
    • Seasonal mesozooplankton patterns and timing of life history events in high-arctic fjord environments 

      Søreide, Janne; Dmoch, Katarzyna; Blachowiak-Samolyk, Katarzyna; Trudnowska, Emilia; Daase, Malin (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-11)
      Seasonal patterns in mesozooplankton composition, vertical distribution, and timing of reproduction are challenging to study in the open sea due to ocean currents and mix of populations of different origins. Sill fjords, on the other hand, with restricted water exchange, are ideal locations for studying taxa- and community-specific adaptations to the prevailing environment. Here, we present ...
    • Seasonal variability in non-consumptive mortality of Arctic zooplankton 

      Daase, Malin; Søreide, Janne E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-04)
      Recent observations from high-latitude marine ecosystems indicate that non-consumptive mortality may be particularly high in Arctic zooplankton during the polar night. Here we have estimated the contribution of dead organisms to the mesozooplankton community in the high Arctic (Svalbard 78–81oN) during the polar night (January), in spring (May) and in late summer (end of August). To identify in situ ...
    • 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 (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-04)
      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 in Northern Norway based on monthly sampling between November 2018 and February 2020. We combined traditional morphological zooplankton identification with DNA metabarcoding of a 313 ...
    • Surface aggregations of Calanus finmarchicus during the polar night 

      Espinasse, Boris Dristan; Daase, Malin; Halvorsen, Elisabeth; Reigstad, Marit; Berge, Jørgen; Basedow, Sünnje Linnéa (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-16)
      While marine ecosystems in polar areas were thought to be mostly inactive during the polar night, recent observations in the Arctic highlight that dynamic biological interactions occur across all trophic levels. One particularly interesting observation made repeatedly is the occurrence of Calanus finmarchicus, a key species at the base of the food web, in the upper part of the water column in early ...
    • 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; Tidsskriftartikkel; Peer reviewed, 2018-01-10)
      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 dark, light is most often considered as pollution, with increasing appreciation of its negative ecological effects. Using an Autonomous Surface Vehicle fitted with a hyperspectral ...