• Arctic Observations Identify Phytoplankton Community Composition as Driver of Carbon Flux Attenuation 

      Wiedmann, Ingrid; Ceballos-Romero, E.; Villa-Alfageme, M.; Renner, Angelika; Dybwad, Christine; van der Jagt, Helga; Svensen, Camilla; Assmy, Philipp; Wiktor, Josef; Tatarek, Agnieszka; Różańska‐Pluta, M.; Iversen, Morten H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-24)
      The attenuation coefficient <i>b</i> is one of the most common ways to describe how strong the carbon flux is attenuated throughout the water column. Therefore, <i>b</i> is an essential input variable in many carbon flux and climate models. Marsay et al. (2015, <a href=https://doi.org/10.1073/pnas.1415311112>https://doi.org/10.1073/pnas.1415311112</a>) proposed that the median surface water temperature ...
    • Atlantification influences zooplankton communities seasonally in the northern Barents Sea and Arctic Ocea 

      Wold, Anette; Hop, Haakon; Svensen, Camilla; Søreide, Janne; Assmann, Karen; Ormańczyk, M.R.; Kwasniewski, S (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      The Barents Sea is undergoing rapid ocean warming with less sea ice and increased Atlantic inflow, shifting the pelagic ecosystem towards a more boreal one, a process referred to as Atlantification. While such changes have already been documented in the southern and central Barents Sea, less is known about the degree of Atlantification in the northern Barents Sea and Arctic Ocean. In this seasonal ...
    • Atlantification influences zooplankton communities seasonally in the northern Barents Sea and Arctic Ocean 

      Wold, Anette; Hop, Haakon; Svensen, Camilla; Søreide, Janne; Assmann, Karen M.; Ormanzcyk, Mateusz; Kwaśniewski, Sławomir (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      The Barents Sea is undergoing rapid ocean warming with less sea ice and increased Atlantic inflow, shifting the pelagic ecosystem towards a more boreal one, a process referred to as Atlantification. While such changes have already been documented in the southern and central Barents Sea, less is known about the degree of Atlantification in the northern Barents Sea and Arctic Ocean. In this seasonal ...
    • Can morphology reliably distinguish between the copepods Calanus finmarchicus and C. glacialis, or is DNA the only way? 

      Choquet, Marvin; Kosobokova, Ksenia; Kwaśniewski, Sławomir; Hatlebakk, Maja Karoline Viddal; Dhanasiri, Anusha Krishanthi Shyama; Melle, Webjørn Raunsgård; Daase, Malin; Svensen, Camilla; Søreide, Janne; Hoarau, Galice Guillaume (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-10)
      Copepods of the genus <i>Calanus</i> play a key role in marine food webs as consumers of primary producers and as prey for many commercially important marine species. Within the genus, <i>Calanus glacialis</i> and <i>Calanus finmarchicus</i> are considered indicator species for Arctic and Atlantic waters, respectively, and changes in their distributions are frequently used as a tool to track climate ...
    • Contrasting physiological responses to future ocean acidification among Arctic copepod populations 

      Thor, Peter; Bailey, Allison Michelle; Dupont, Sam; Calosi, Piero; Søreide, Janne; De Wit, Pierre; Guscelli, Ella; Loubet-Sartrou, Lea; Deichmann, Ida M.; Candee, Martin M.; Svensen, Camilla; King, Andrew Luke; Bellerby, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-17)
      Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid‐base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across ...
    • First record of a rare species, Polyasterias problematica (Prasinophyceae), in Balsfjord, northern Norway 

      Kubiszyn, Anna M; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-13)
      <i>Polyasterias problematica</i> is a poorly investigated prasinophyte species, practically known only from a few, primarily historical studies. Fragmentary information on the species indicates that <i>P. problematica</i> is mainly distributed in the euphotic zone of the Canadian and Russian Arctic, Atlantic Canada, the mid-Atlantic and some European seas. Here, we present the first record of this ...
    • Genetics redraws pelagic biogeography of Calanus 

      Choquet, Marvin Raoul Charles Roger Ren; Haltebakk, Maja; Dhanasiri, Anusha Krishanthi Shyama; Kosobokova, Ksenia N.; Smolina, Irina Vladimirovna; Søreide, Janne; Svensen, Camilla; Melle, Webjørn Raunsgård; Kwasniewski, Slawomir; Eiane, Ketil; Daase, Malin; Tverberg, Vigdis; Skreslet, Stig; Bucklin, Ann; Hoarau, Galice Guillaume (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-20)
      Planktonic copepods of the genus Calanus play a central role in North Atlantic/Arctic marine food webs. Here, using molecular markers, we redrew the distributional ranges of Calanus species inhabiting the North Atlantic and Arctic Oceans and revealed much wider and more broadly overlapping distributions than previously described. The Arctic shelf species, C. glacialis, dominated the zooplankton ...
    • High abundances of small copepods early developmental stages and nauplii strengthen the perception of a non-dormant Arctic winter 

      Barth-Jensen, Coralie Marie Christine; Daase, Malin; Ormańczyk, M.R.; Varpe, Øystein; Kwaśniewski, Sławomir; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-15)
      The traditional view is that the Arctic polar night is a quiescent period for marine life, but recent reports of high levels of feeding and reproduction in both pelagic and benthic taxa have challenged this. We examined the zooplankton community present in Svalbard fjords, coastal waters, and the shelf break north of Svalbard, during the polar night. We focused on the population structure of abundant ...
    • Impact of a Dinophysis acuminata Bloom on the Copepod Acartia clausi: First Indications 

      Frangoulis, Constantin; Christou, Epaminondas D.; Varkitzi, Ioanna; Zervoudaki, Soultana; Maneiro, Isabel; Svensen, Camilla; Pagou, Kalliopi; Assimakopoulou, Georgia; Hatzianestis, Ioannis; Granéli, Edna (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-12)
      Faecal pellet production and content along with egg production of the dominant copepod species Acartia clausi were studied in the Thermaikos Gulf (NW Aegean Sea) during a prebloom and a bloom of the toxic dinoflagellate Dinophysis acuminata. Both faecal pellet production (6.8–8.6 ind<sup>−1</sup> d <sup>−1</sup> ) and egg production (15.8–47.6 ind<sup>−1</sup> d <sup>−1</sup> ) appeared unrelated ...
    • New insights into the Barents Sea Calanus glacialis population dynamics and distribution 

      Aarflot, Johanna Myrseth; Eriksen, Elena; Prokopchuk, Irina P.; Svensen, Camilla; Søreide, Janne; Wold, Anette; Skogen, Morten D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-18)
      Arctic copepods are major grazers and vital food for planktivores in polar ecosystems but challenging to observe due to remoteness and seasonal sea ice coverage. Models offer higher spatio-temporal resolution, and individual-based models (IBMs) are useful since they incorporate individual variability which characterizes most copepod populations. Here, we present an IBM of the Arctic copepod Calanus ...
    • Production of dissolved organic carbon by Oithona nana (Copepoda: Cyclopoida) grazing on two species of dinoflagellates 

      Svensen, Camilla; Vernet, Maria (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-22)
    • Seasonal dynamics of meroplankton in a high-latitude fjord 

      Michelsen, Helena Kling; Svensen, Camilla; Reigstad, Marit; Nilssen, Einar Magnus; Pedersen, Torstein (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-09)
      Knowledge on the seasonal timing and composition of pelagic larvae of many benthic invertebrates, referred to as meroplankton, is limited for high-latitude fjords and coastal areas. We investigated the seasonal dynamics of meroplankton in the sub-Arctic Porsangerfjord (70°N), Norway, by examining their seasonal changes in relation to temperature, chlorophyll a and salinity. Samples were collected ...
    • Small copepods matter: Population dynamics of Microsetella norvegica in a high-latitude coastal ecosystem 

      Svensen, Camilla; Antonsen, Maria Terese; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-04)
      We investigated the population dynamics of a small and little-studied harpacticoid copepod, <i>Microsetella norvegica</i>, in a sub-Arctic Norwegian fjord (Balsfjord 69°N). We sampled with a 90 μm mesh WP-2 net and a 20 L Go-Flo bottle and found that the WP-2 under-sampled all juvenile stages. The abundance and biomass were high, peaking in June with 9349 × 10-<sup>3</sup> ind. m<sup>−2</sup> and ...
    • Spatial patterns of spring meroplankton along environmental gradients in a sub-Arctic fjord 

      Michelsen, Helena Kling; Nilssen, Einar Magnus; Pedersen, Torstein; Reigstad, Marit; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)
      The spatial patterns in abundance and composition of benthic invertebrate larvae (meroplankton), the correlation between these patterns and environmental variables (temperature, salinity and chl a) and the relative abundance of meroplankton in the mesozooplankton community were investigated in the sub-Arctic Porsangerfjord, Norway (70° N). Zooplankton samples and CTD-profiles were collected at ...
    • Temperature-dependent egg production and egg hatching rates of small egg-carrying and broadcast-spawning copepods Oithona similis, Microsetella norvegica and Microcalanus pusillus 

      Barth-Jensen, Coralie Marie Christine; Koski, Marja; Varpe, Øystein; Glad, Peter; Wangensteen, Owen Simon; Præbel, Kim; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-07)
      Reproductive rates of copepods are temperature-dependent, but poorly known for small copepods at low temperatures, hindering the predictions of population dynamics and secondary production in high-latitude ecosystems. We investigated egg hatching rates, hatching success and egg production of the small copepods <i>Oithona similis</i> and <i>Microsetella norvegica</i> (sac spawners) and <i>Microcalanus ...
    • Temperature-dependent egg production and egg hatching rates of small egg-carrying and broadcast-spawning copepods Oithona similis, Microsetella norvegica and Microcalanus pusillus 

      Barth-Jensen, Coralie; Koski, Marja; Varpe, Øystein; Glad, Peter; Wangensteen, Owen S.; Præbel, Kim; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-07)
      Reproductive rates of copepods are temperature-dependent, but poorly known for small copepods at low temperatures, hindering the predictions of population dynamics and secondary production in high-latitude ecosystems. We investigated egg hatching rates, hatching success and egg production of the small copepods <i>Oithona similis</i> and <i>Microsetella norvegica</i> (sac spawners) and <i>Microcalanus ...
    • Temporal and spatial dynamics of the invasive red king crab and native brachyuran and anomuran larvae in Norwegian waters 

      Michelsen, Helena Kling; Nilssen, Einar Magnus; Pedersen, Torstein; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-16)
      This study investigates the temporal and spatial patterns of larval stages of the invasive red king crab <i>Paralithodes camtschaticus</i> (RKC) and co-existing native brachyurans and anomurans in a Norwegian fjord. It is one of few field studies describing the larval stage of native and invasive brachyurans and anomurans in the southern Barents Sea. Larvae were collected at 6 to 18 stations at ...
    • Zooplankton communities associated with new and regenerated primary production in the Atlantic inflow north of Svalbard 

      Svensen, Camilla; Halvorsen, Elisabeth; Vernet, Maria; Franzè, Gayantonia; Dmoch, Katarzyna; Lavrentyev, Peter J.; Kwasniewski, Slawomir (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      The Arctic Ocean is changing rapidly with respect to ice cover extent and volume, growth season duration and biological production. Zooplankton are important components in the arctic marine food web, and tightly coupled to the strong seasonality in primary production. In this study, we investigate zooplankton composition, including microzooplankton, copepod nauplii, as well as small and large copepod ...