Now showing items 181-200 of 1607

    • Sea-ice decline could keep zooplankton deeper for longer 

      Flores, Hauke; Veyssière, Gaëlle; Castellani, Giulia; Wilkinson, Jeremy; Hoppmann, Mario; Karcher, Michael; Valcic, Lovro; Cornils, Astrid; Geoffroy, Maxime; Nicolaus, Marcel; Niehoff, Barbara; Priou, Pierre; Schmidt, Katrin; Stroeve, Julienne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-28)
      As Arctic sea ice deteriorates, more light enters the ocean, causing largely unknown effects on the ecosystem. Using an autonomous biophysical observatory, we recorded zooplankton vertical distribution under Arctic sea ice from dusk to dawn of the polar night. Here we show that zooplankton ascend into the under-ice habitat during autumn twilight, following an isolume of 2.4 × 10<sup>−4</sup>  ...
    • The roles of brain lipids and polar metabolites in the hypoxia tolerance of deep-diving pinnipeds 

      Martens, Gerrit A.; Geßner, Cornelia; Folkow, Lars; Creydt, Marina; Fischer, Markus; Burmester, Thorsten (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-14)
      Lipids make up more than half of the human brain's dry weight, yet the composition and function of the brain lipidome is not well characterized. Lipids not only provide the structural basis of cell membranes, but also take part in a wide variety of biochemical processes. In neurodegenerative diseases, lipids can facilitate neuroprotection and serve as diagnostic biomarkers. The study of organisms ...
    • Herbivory and warming have opposing short-term effects on plant-community nutrient levels across high-Arctic tundra habitats 

      Petit Bon, Matteo; Bråthen, Kari Anne; Ravolainen, Virve; Ottaviani, Gianluigi; Böhner, Hanna; Jonsdottir, Ingibjørg (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-11)
      Environmental changes can rapidly alter standing biomass in tundra plant communities; yet, to what extent can they modify plant-community nutrient levels? Nutrient levels and their changes can affect biomass production, nutrient cycling rates and nutrient availability to herbivores. We examined how environmental perturbations alter Arctic plant-community leaf nutrient concentrations (percentage of ...
    • Ecological Drivers of Mercury Bioaccumulation in Fish of a Subarctic Watercourse 

      Amundsen, Per-Arne; Henriksson, Nina Matilda; Poste, Amanda; Prati, Sebastian; Power, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-02)
      Mercury (Hg) is a serious concern for aquatic ecosystems because it may biomagnify to harmful concentrations within food webs and consequently end up in humans that eat fish. However, the trophic transfer of mercury through the aquatic food web may be impacted by several factors related to network complexity and the ecology of the species present. The present study addresses the interplay between ...
    • First analysis of an Arctic sea ice meiofauna food web based on abundance, biomass and stable isotope ratios 

      Gradinger, Rolf; Bluhm, Bodil (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-23)
      Particulate organic carbon (POC) produced in sea ice is often included in stable isotopic food web studies of polar seas as a single value of particulate organic matter (POM), i.e. ‘ice POM’. During 10 field trips to landfast ice off Alaska’s north coast, we examined the seasonal contribution of sea ice-associated meiofauna to total POM and the trophic structure within the sea ice using bulk carbon ...
    • Relating polar bears killed, human presence, and ice conditions in Svalbard 1987–2019 

      Vongraven, Dag; Amstrup, S.C.; McDonald, T.L.; Mitchell, J.; Yoccoz, Nigel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-28)
      Conflicts between humans and polar bears have been predicted to increase as polar bear prime habitat, sea ice, is decreasing. In Svalbard, a strict protection and control schemes have secured near complete records of bears killed and found dead since 1987. We analyzed the trend in the number of kills and related this to human visitation to the archipelago. We found a slight decrease in the number ...
    • Foraging movements of humpback whales relate to the lateral and vertical distribution of capelin in the Barents Sea 

      Vogel, Emma; Skalmerud, Emma; Biuw, Martin; Blanchet, Marie-Anne; Kleivane, Lars; Skaret, Georg; Øien, Nils; Rikardsen, Audun (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-24)
      Understanding how individual animals modulate their behaviour and movement patterns in response to environmental variability plays a central role in behavioural ecology. Marine mammal tracking studies typically use physical environmental characteristics that vary, and/or proxies of prey distribution, to explain predator movements. Studies linking predator movements and the actual distributions ...
    • Validation of pop-up satellite archival tags (PSATs) on Atlantic cod (Gadus morhua) in a Greenland fjord 

      Nielsen, Julius; Estévez-Barcia, Daniel; Post, Søren; Christensen, Helle Torp; Retzel, Anja; Meire, Lorenz; Rigét, Frank; Strøm, John Frederik; Rikardsen, Audun H.; Hedeholm, Rasmus (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-28)
      Traditional tagging techniques are simple and cost-effective, but inferences require recaptures and data on movement/migration are limited to a start and end position at unpredictable intervals. Pop-up satellite archival tags (PSATs) offer other opportunities, as they provide positions at pre-programmed times and collect on-route data, which can be used to describe position, behavior, and habitat ...
    • Analyzing the Geometry and Dynamics of Viral Structures: A Review of Computational Approaches Based on Alpha Shape Theory, Normal Mode Analysis, and Poisson–Boltzmann Theories 

      Hsieh, Yin-Chen; Delarue, Marc; Orland, Henri; Koehl, Patrice (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-13)
      The current SARS-CoV-2 pandemic highlights our fragility when we are exposed to emergent viruses either directly or through zoonotic diseases. Fortunately, our knowledge of the biology of those viruses is improving. In particular, we have more and more structural information on virions, i.e., the infective form of a virus that includes its genomic material and surrounding protective capsid, and ...
    • Estimating Surface Concentrations of Calanus finmarchicus Using Standardised Satellite-Derived Enhanced RGB Imagery 

      McCarry, Cait L.; Basedow, Sünnje Linnéa; Davies, Emlyn John; McKee, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      Calanus finmarchicus is a keystone zooplankton species that is commercially harvested and is critical in sustaining many important fisheries in the North Atlantic. However, due to their patchy population distributions, they are notoriously difficult to map using traditional ship-based techniques. This study involves the use of a combined approach of standardized ocean colour imagery and radiative ...
    • Weak seasonality in benthic food web structure within an Arctic inflow shelf region 

      Ziegler, Amanda; Bluhm, Bodil; Renaud, Paul Eric; Jørgensen, Lis Lindal (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-23)
      The Arctic Ocean is characterized by pronounced seasonality in the quantity and quality of organic matter exported from the surface ocean. While it is well established that changes in food availability can alter the abundance, biomass and function of benthic organisms, the impact on food web structure is not well studied. We used bulk carbon and nitrogen stable isotope analysis to assess the quantity ...
    • The One Ocean Expedition: Science and Sailing for the Ocean We Want 

      Huse, Geir; Baussant, Thierry; Becker, Meike; Biuw, Martin; Bødtker, Gunhild; Cook, Jeremy; Gomiero, Alessio; Grøsvik, Bjørn Einar; Handegard, Nils Olav; Hestnes, Arne Johan; Hole, Lars Robert; Husson, Berengere; Jaccard, Pierre Franqois; Johannessen, Johnny Andre; Krolicka, Adriana; Lien, Vidar Surén; Lindemann, Christian; Olsen, Are; Renner, Angelika; Lid, Sjur Ringheim; Steen-Larsen, Hans Christian; Strand, Espen; Westgaard, Jon-Ivar; Pedersen, Geir (Research report; Forskningsrapport, 2023-08-24)
      The One Ocean Expedition (OOE) was a 20-month long circumnavigation of the globe by the Norwegian sail training vessel Statsraad Lehmkuhl, and a recognised part of the UN decade of Ocean Science for Sustainable Development. The ship was equipped with modern instrumentation to collect high-quality data on ocean physics, chemistry, and biology. Many of the data series were available in near real time ...
    • Cruise report Hywind Tampen 13 to 28 March 2023 - Cruise no. 2023001004 G.O. Sars 

      Utne-Palm, Anne Christine; Søiland, Henrik; Sveistrup, Anne; Renner, Angelika; Ross, Rebecca; Moy, Frithjof Emil; Paskyabi, Mosttafa Bakhoday; Totland, Atle; Hannaas, Sigurd; de Jong, Karen; Gonzalez-Mirelis, Genoveva; Hovland, Terje; Pedersen, Geir; Wilhelmsen, Jan Frode; Majaneva, Markus; Heum, Sverre Waardal; Skjold, William; Vågenes, Stig; Skaret, Georg; Corus, Finn; Voronkov, Andrey; Kielland, Leonard (Research report; Forskningsrapport, 2023)
      There is very little knowledge related to how floating windfarms effect the marine environment as this is such a new “product”. Thus, the data that we gathered on this cruise will be novel in that sense. The aim of the cruise was to look at possible effects of the windfarm on the marine environment. Based on limited cruise time and tough weather conditions around Hywind Tampen we had to be selective ...
    • Potential effects of petroleum pollution and increasing water temperature on life-history traits in polar cod (Boreogadus saida) 

      Bender, Morgan Lizabeth; Frantzen, Marianne; Geoffroy, Maxime; Meador, James P.; Nahrgang, Jasmine (Conference object; Konferansebidrag, 2017)
    • Earlier sea-ice melt extends the oligotrophic summer period in the Barents Sea with low algal biomass and associated low vertical flux 

      Kohlbach, Doreen; Goraguer, Lucie; Bodur, Yasemin V.; Müller, Oliver; Amargant Arumí, Martí; Blix, Katalin; Bratbak, Gunnar; Chierici, Melissa; Dabrowska, Anna Maria; Dietrich, Ulrike; Edvardsen, Bente; Garcia, Laura; Gradinger, Rolf Rudolf; Hop, Haakon; Jones, Elizabeth Marie; Øyvind, Lundesgaard; Olsen, Lasse Mork; Reigstad, Marit; Saubrekka, Karoline; Tatarek, Agnieszka; Wiktor, Josef Maria; Wold, Anette; Assmy, Philipp (Journal article; Tidsskriftartikkel, 2023-03-27)
      The decrease in Arctic sea-ice extent and thickness as a result of global warming will impact the timing, duration, magnitude and composition of phytoplankton production with cascading effects on Arctic marine food-webs and biogeochemical cycles. Here, we elucidate the environmental drivers shaping the composition, abundance, biomass, trophic state and vertical flux of protists (unicellular eukaryotes), ...
    • Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord 

      Jorda Molina, Eric; Renaud, Paul Eric; Silberberger, Marc J.; Sen, Arunima; Bluhm, Bodil; Carroll, Michael Leslie; Ambrose, William; Cottier, Finlo Robert; Reiss, Henning (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-05)
      Amid the alarming atmospheric and oceanic warming rates taking place in the Arctic, western fjords around the Svalbard archipelago are experiencing an increased frequency of warm water intrusions in recent decades, causing ecological shifts in their ecosystems. However, hardly anything is known about their potential impacts on the until recently considered stable and colder northern fjords. We ...
    • Fifteen research needs for understanding climate change impacts on ecosystems and society in the Norwegian High North 

      Kebir, Zina Asnah; Chambers, Catherine; Frainer, André; Hausner, Vera Helene; Lennert, Ann Eileen; Lento, Jennifer; Poste, Amanda; Ravolainen, Virve; Renner, Angelika; Thomas, David N.; Waylen, Kerry (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-07)
      There is an urgent need to understand and address the risks associated with a warming climate for ecosystems and societies in the Arctic and sub-Arctic regions. There are major gaps in our understanding of the complex effects of climate change—including extreme events, cascading impacts across ecosystems, and the underlying socioecological dynamics and feedbacks—all of which need collaborative efforts ...
    • Pathogen Exposure in White Whales (Delphinapterus leucas) in Svalbard, Norway 

      Nymo, Ingebjørg Helena; Siebert, Ursula; Baechlein, Christine; Postel, Alexander; Breines, Eva Marie; Lydersen, Christian; Kovacs, Kit M.; Tryland, Morten (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-29)
      The Svalbard white whale (Delphinapterus leucas) population is one of the smallest in the world, making it particularly vulnerable to challenges such as climate change and pathogens. In this study, serum samples from live captured (2001-2016) white whales from this region were investigated for influenza A virus (IAV) antibodies (Abs) (n = 27) and RNA (n = 25); morbillivirus (MV) Abs (n = 3) and RNA ...
    • Assessing public perception and willingness to pay for renewable energy in Pakistan through the theory of planned behavior 

      Ud Din, Shahab; Wimalasiri, Ruminda; Ehsan, Muhsan; Liang, Xue; Ning, Fulong; Guo, Dongdong; Manzoor, Zaira; Abu-Alam, Tamer; Abioui, Mohamed (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-16)
      With growing urbanization and increasing world population, energy demand also increases. A significant portion of the world’s energy comes from fossil fuels, and these sources of energy are declining rapidly at the current consumption rate. There are also growing environmental concerns on the use of fossil fuels increasing greenhouse gas emissions. In this regard, renewable energy (RE) shows promising ...
    • The circumpolar impacts of climate change and anthropogenic stressors on Arctic cod (Boreogadus saida) and its ecosystem 

      Geoffroy, Maxime; Bouchard, Caroline; Flores, Hauke; Robert, Dominique; Gjøsæter, Harald; Hoover, Carie; Hop, Haakon; Hussey, Nigel E.; Nahrgang, Jasmine; Steiner, Nadja; Bender, Morgan; Berge, Jørgen; Castellani, Giulina; Chernova, Natalia; Copeman, Louise; David, Carmen; Deary, Alison; Divoky, George; Dolgov, Andrey; Duffy-Anderson, Janet; Dupont, Nicolas; Durant, Joël M.; Elliott, Kyle; Gauthier, Stéphane; Goldstein, Esther D.; Rolf, Gradinger; Hedges, Kevin; Herbig, Jennifer; Laurel, Ben; Loseto, Lisa; Maes, Sarah; Mark, Felix; Mosbech, Anders; Pedro, Sara; Petitt-Wade, Harri; Prokopchuk, Irina; Paul E, Renaud; Schembri, Sarah; Vestfals, Cathleen; Walkusz, Wojciech (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-08)
      Arctic cod biomass are predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community will likely fluctuate in accordance with cold and warm periods. A reduced abundance of Arctic cod will negatively affect the abundance, distribution, and physiological condition of certain predators, whereas some predators will successfully adapt to a more boreal diet. Regional ...