Now showing items 101-120 of 1914

    • Small rodent population cycles and plants – after 70 years, where do we go? 

      Soininen, Eeva M; Neby, Magne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-12)
      Small rodent population cycles characterise northern ecosystems, and the cause of these cycles has been a long-lasting central topic in ecology, with trophic interactions currently considered the most plausible cause. While some researchers have rejected plant–herbivore interactions as a cause of rodent cycles, others have continued to research their potential roles. Here, we present an overview ...
    • Interactive effects of ocean acidification and temperature on oxygen uptake rates in Calanus hyperboreus nauplii 

      Espinel Velasco, Nadjejda; Gawinski, Christine; Kohlbach, Doreen; Pitusi, Vanessa; Graeve, Martin; Hop, Haakon (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-26)
      The Arctic region is undergoing rapid and significant changes, characterized by high rates of acidification and warming. These transformations prompt critical questions about the resilience of marine communities in the face of environmental change. In the Arctic, marine zooplankton and in particular calanoid copepods play a vital role in the food web. Changes in environmental conditions could ...
    • Evaluation of meso- and microplastic ingestion by the northern fulmar through a non-lethal sampling method 

      Collard, France; Strøm, Hallvard; Fayet, Marie-Océane; Gudmundsson, Fannar Theyr; Herzke, Dorte; Hotvedt, Ådne; Løchen, Arja Katrina Lea Arnesen; Malherbe, Cédric; Eppe, Gauthier; Gabrielsen, Geir W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-11)
      An increasing number of organisms from the polar regions are reported contaminated by plastic. Rarely a nonkilling sampling method is used. In this study we wanted to assess plastic levels using stomach flushing and evaluate the method suitability for further research and monitoring. The stomach of 22 fulmars from Bjørnøya, Svalbard, were flushed with water in the field. On return to the laboratory, ...
    • Copepods’ true colors: astaxanthin pigmentation as an indicator of fitness 

      Vilgrain, Laure; Maps, Frédéric; Basedow, Sünnje Linnéa; Trudnowska, Emilia; Madoui, Mohammed-Amin; Niehoff, Barbara; Ayata, Sakina‐Dorothée (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      Pigmentation is often overlooked in zooplankton, since these organisms are mostly colorless to fit the translucid water medium. However, one of the dominant zooplankton taxa in aquatic ecosystems—copepods—often show a bright red-orange or blue coloration owing to the accumulation of carotenoid pigments in some parts of their bodies. Even though there are many functional traits describing copepod’s ...
    • Patterns and repeatability of multi-ecotype assemblages of sympatric salmonids 

      Blain, Stephanie A.; Schluter, Dolph; Adams, Colin E.; Amundsen, Per-Arne; Knudsen, Rune; Chavarie, Louise (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-04)
      Aim: High repeatability among assemblages of closely related but ecologically distinct ecotypes implies predictability in evolution and assembly of communities. The conditions under which ecotype assemblages form predictably, and the reasons, have been little investigated. Here, we test whether repeatability declines as the number of ecotypes builds.<p> <p>Location: Postglacial lakes with a ...
    • Water column distribution of zooplanktonic size classes derived from in-situ plankton profilers: Potential use to contextualize contaminant loads in plankton 

      Espinasse, Boris Dristan; Pagano, M.; Basedow, Sünnje Linnéa; Chevalier, C.; Malengros, D.; Carlotti, F. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      Pollution is one of the main anthropogenic threats to marine ecosystems. Studies analysing the accumulation and transfer of contaminants in planktonic food webs tend to rely on samples collected in discrete water bodies. Here, we assessed the representativeness of measurements at the chlorophyll-a maximum layer during the MERITEHIPPOCAMPE cruise for the entire water column by investigating the ...
    • Long-term monitoring of exposure to toxic and essential metals and metalloids in the tawny owl (Strix aluco): Temporal trends and influence of spatial patterns 

      Devalloir, Quentin; Fritsch, Clementine; Bangjord, Georg; Bårdsen, Bård-Jørgen; Bourgeon, Sophie; Eulaers, Igor; Bustnes, Jan Ove (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-10)
      As a result of regulatory decisions, atmospheric deposition of most toxic metals and metalloids (MEs) has decreased in Europe over the past few decades. However, little is known about how this reduction translates into exposure at higher trophic levels in the terrestrial environment where temporal trends may be spatially heterogeneous due to local current or legacy sources of emissions (e.g., industry) ...
    • Ingestion of car tire crumb rubber and uptake of associated chemicals by lumpfish (Cyclopterus lumpus) 

      Hägg, Fanny; Herzke, Dorte; Nikiforov, Vladimir; Booth, Andy; Sperre, Kristine Hopland; Sørensen, Lisbet; Egeness, Mari Jystad; Halsband, Claudia (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-12)
      Car tire rubber constitutes one of the largest fractions of microplastics emissions to the environment. The two main emission sources are tire wear particles (TWPs) formed through abrasion during driving and runoff of crumb rubber (CR) granulate produced from end-of-life tires that is used as infill on artificial sports fields. Both tire wear particles and crumb rubber contain a complex mixture ...
    • Deep ocean particle flux in the Northeast Atlantic over the past 30 years: carbon sequestration is controlled by ecosystem structure in the upper ocean 

      Lampitt, Richard S.; Briggs, Nathan; Cael, B. B.; Espinola, Benoit; Hélaouët, Pierre; Henson, Stephanie A.; Norrbin, Maria Fredrika; Pebody, Corinne A.; Smeed, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-16)
      The time series of downward particle flux at 3000 m at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) in the Northeast Atlantic is presented for the period 1989 to 2018. This flux can be considered to be sequestered for more than 100 years. Measured levels of organic carbon sequestration (average 1.88 gm<sup>−2</sup> y<sup>−1</sup> ) are higher on average at this location than at ...
    • 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 ...
    • Assessment of risk and risk-reducing measures related to the introduction and dispersal of the invasive alien carpet tunicate Didemnum vexillum in Norway 

      Järnegren, Johanna; Gulliksen, Bjørn; Husa, Vivian; Malmstrøm, Martin; Oug, Eivind; Berg, Paul Ragnar; Bryn, Anders; Geange, Sonya Rita; Hindar, Kjetil; Hole, Lars Robert; Kausrud, Kyrre Linné; Kirkendall, Lawrence Richard; Nielsen, Anders; Sandercock, Brett Kevin; Thorstad, Eva Bonsak; Velle, Gaute (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-17)
      Didemnum vexillum is colonial sea squirt, a marine species which originates from the northwest Pacific; it was first recorded in Norway in November 2020. Didemnum vexillum is an alien species, meaning that it is a species that has been transferred from its original region to other regions of the world through human activity, and it had not previously been recorded in Norwegian waters. The species ...
    • The northernmost hyperspectral FLoX sensor dataset for monitoring of high-Arctic tundra vegetation phenology and Sun-Induced Fluorescence (SIF) 

      Tømmervik, Hans; Julitta, Tommaso; Nilsen, Lennart; Park, Taejin; Burkart, Andreas; Ostapowicz, Katarzyna Anna; Karlsen, Stein Rune; Parmentier, Frans-Jan W.; Pirk, Norbert; Bjerke, Jarle W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-16)
      A hyperspectral field sensor (FloX) was installed in Adventdalen (Svalbard, Norway) in 2019 as part of the Svalbard Integrated Arctic Earth Observing System (SIOS) for monitoring vegetation phenology and Sun-Induced Chlorophyll Fluorescence (SIF) of high-Arctic tundra. This northernmost hyperspectral sensor is located within the footprint of a tower for long-term eddy covariance flux measurements ...
    • Ambient Temperature Effects on the Spring and Autumn Somatic Growth Trajectory Show Plasticity in the Photoneuroendocrine Response Pathway in the Tundra Vole 

      van Dalum, Mattis Jayme; van Rosmalen, Laura; Appenroth, Daniel; Cazarez Marquez, Fernando; Roodenrijs, Renzo T. M.; de Wit, Lauren; Hut, Roelof A.; Hazlerigg, David Grey (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-11)
      Seasonal mammals register photoperiodic changes through the photoneuroendocrine system enabling them to time seasonal changes in growth, metabolism, and reproduction. To a varying extent, proximate environmental factors like ambient temperature (Ta) modulate timing of seasonal changes in physiology, conferring adaptive flexibility. While the molecular photoneuroendocrine pathway governing the seasonal ...
    • Don't mind if I do: Arctic humpback whales respond to winter foraging opportunities before migration 

      Kettemer, Lisa Elena; Ramm, Theresia; Broms, Fredrik Björn; Biuw, Martin; Blanchet, Marie-Anne; Bourgeon, Sophie; Dubourg, Paul; Ellendersen, Anna C. J.; Horaud, Mathilde; Kershaw, Joanna; Miller, Patrick J. O.; Øien, Nils Inge; Pallin, Logan J.; Rikardsen, Audun H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-06)
      Migration patterns are fundamentally linked to the spatiotemporal distributions of prey. How migrating animals can respond to changes in their prey’s distribution and abundance remains largely unclear. During the last decade, humpback whales (Megaptera novaeangliae) used specific winter foraging sites in fjords of northern Norway, outside of their main summer foraging season, to feed on herring ...
    • Seasonal patterns of vertical flux in the northwestern Barents Sea under Atlantic Water influence and sea-ice decline 

      Bodur, Yasemin Vicdan; Renaud, Paul Eric; Goraguer, Lucie Hélène Marie; Amargant I Arumi, Marti; Assmy, Philipp Kurt Wolf; Dabrowska, Anna Maria; Marquardt, Miriam; Renner, Angelika; Tatarek, Agnieska; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-27)
      The northern Barents Sea is a productive Arctic inflow shelf with a seasonal ice cover and as such, a location with an efficient downward export of particulate organic matter through the biological carbon pump. The region is under strong influence of Atlantification and sea-ice decline, resulting in a longer open water and summer period. In order to understand how these processes influence the ...
    • Temporal and spatial variability of sympagic metazoans in a high-Arctic fjord, Svalbard 

      Pitusi, Vanessa; Gradinger, Rolf Rudolf; Søreide, Janne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-08)
      Svalbard is one of the fastest warming regions in the Arctic including massive loss in fjord sea ice both in terms of area coverage, ice thickness and duration. Sea ice is a habitat for a wide variety of microscopic flora and fauna, and we know little about the impact of accelerated loss of sea ice on this unique sea ice community. Here, we present the first study on the seasonal progression and ...
    • Radiolaria and Phaeodaria (siliceous Rhizaria) in south-western and northern Norwegian fjords during late summer 2016: dominant species and biomass in shallow-water assemblages 

      Ikenoue, Takahito; Bjørklund, Kjell Rasmus; Krabberød, Anders Kristian; Nishino, Shigeto; Wassmann, Paul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-21)
      To determine the present-day community composition of siliceous Rhizaria (Radiolaria and Phaeodaria) in Norwegian fjords, plankton tows were conducted in south-western and northern Norwegian fjords in September 2016. The mean total abundance of radiolarians was 306 m<sup>–3</sup> in the Sognefjord complex, which was the southern research site, and, in the north, 945 m<sup>–3</sup> in Malangen and ...
    • A long-established invasive species alters the functioning of benthic biofilms in lakes 

      McKie, Brendan G.; Tattersdill, Kristina; Ecke, Frauke; Frainer Barbosa, Andre; Sponseller, Ryan A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-21)
      Invasive species often transform environmental conditions, exclude native species and alter ecosystem functioning, including key ecosystem processes underpinning nutrient and energy cycles. However, such impacts have been most documented during periods of invasive species dominance; their influences on functioning at lower relative abundances and after long-term establishment are less well-known.<p> <p>We ...
    • Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack-Recent insights on these historically overlooked features 

      Smith, Madison M.; Muilwijk, Morven; Chierici, Melissa; Fer, Ilker; Fransson, Agneta; Gardner, Jessie; Granskog, Mats; Müller, Oliver; Salganik, Evgenii; Angot, He´le`ne; Chamberlain, Emelia J.; Droste, Elise S.; Karam, Salar; Webb, Alison L.; Archer, Stephen D.; Beck, Ivo; Blomquist, Byron W.; Bowman, Jeff; Boyer, Matthew; Bozzato, Deborah; Creamean, Jessie; D’Angelo, Alessandra; Delille, Bruno; Fong, Allison A.; Fuchs, Niels; Hoppe, Clara J. M.; Hoppema, Mario; Hoppmann, Mario; Mock, Thomas; Muller, Sofia; Nicolaus, Marcel; Nomura, Daiki; Petääja, Tuukka; Schmale, Julia; Schmidt, Katrin; Schulz, Kirstin M.; Shupe, Matthew D.; Stefels, Jacqueline; Thielke, Linda; Tippenhauer, Sandra; Ulfsbo, Adam; van Leeuwe, Maria; Webster, Melinda; Yoshimura, Masaki; Zhan, Liyang (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-07)
      The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, ...
    • Seasonal dynamics of sea-ice protist and meiofauna in the northwestern Barents Sea 

      Marquardt, Miriam; Goraguer, Lucie Hélène Marie; Assmy, Philipp Kurt Wolf; Bluhm, Bodil Annikki Ulla Barbro; Aaboe, Signe; Down, Emily; Patrohay, Evan; Edvardsen, Bente; Tatarek, Agnieszka; Smola, Zofia; Wiktor, Józef; Gradinger, Rolf Rudolf (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-27)
      The rapid decline of Arctic sea ice makes understanding sympagic (ice-associated) biology a particularly urgent task. Here we studied the poorly known seasonality of sea-ice protist and meiofauna community composition, abundance and biomass in the bottom 30 cm of sea ice in relation to ice properties and ice drift trajectories in the northwestern Barents Sea. We expected low abundances during the ...