Now showing items 1465-1484 of 1515

    • Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean 

      Randelhoff, Achim; Fer, Ilker; Sundfjord, Arild; Tremblay, Jean-Éric; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-31)
      <p>This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. ...
    • Vertical movements of Atlantic salmon postsmolts relative to measures of salinity and water temperature during the first phase of the marine migration 

      Davidsen, Jan Grimsrud; Plantalech Manel-la, Nuria; Thorstad, E.B; Økland, F.; Sivertsgård, Rolf; McKinley, R.S; Finstad, B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2009)
      The migratory behaviour of hatchery-reared Atlantic salmon, Salmo salar L., post-smolts during the first phase of the marine migration was examined to assess their susceptibility to salmon lice, Lepeophtheirus salmonis (Krøyer), infestations. Swimming depths of eight post-smolts relative to the measured salinity and temperature were monitored for an average of 11.4 h following release outside the ...
    • Vertical redistribution of principle water masses on the Northeast Greenland Shelf 

      Gjelstrup, Caroline V.B.; Sejr, Mikael K.; de Steur, Laura; Schou Christiansen, Jørgen; Granskog, Mats A.; Koch, Boris P.; Møller, Eva Friis; Winding, Mie H.S.; Stedmon, Colin A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-10)
      The Northeast Greenland shelf (NEGS) is a recipient of Polar Water (PW) from the Arctic Ocean, Greenland Ice Sheet melt, and Atlantic Water (AW). Here, we compile hydrographical measurements to quantify long-term changes in fjords and coastal waters. We find a profound change in the vertical distribution of water masses, with AW shoaling >60 m and PW thinning >50 m since early 2000’s. The properties ...
    • Vicariance, dispersal, and hybridization in a naturally fragmented system: the afro-alpine endemics Carex monostachya and C. runssoroensis (Cyperaceae) 

      Gizaw, Abel; Kifilemichael, Tigist Wondimu; Tusiime, Felly Mugizi; Masao, Catherine; Abdi, Ahmed Abdikhadir; Popp, Magnus; Ehrich, Dorothee; Nemomissa, Sileshi; Brochmann, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-08)
      The naturally fragmented habitat on the tallest African mountains provides a good model system to study vicariance, dispersal, and hybridization. Many mountains are separated by lowland that likely was unsuitable for high-alpine plants even during cold climatic periods. <br> We explore the relative importance of these processes using two endemic sister species: the widespread Ethiopian/eastern East ...
    • Vole abundance and reindeer carcasses determine breeding activity of Arctic foxes in low Arctic Yamal, Russia 

      Ehrich, Dorothee; Cerezo, Maite; Rodnikova, Anna Y.; Sokolova, Natalya A.; Fuglei, Eva; Shtro, Victor; Sokolov, Aleksandr A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-16)
      High latitude ecosystems are at present changing rapidly under the influence of climate warming, and specialized Arctic species at the southern margin of the Arctic may be particularly affected. The Arctic fox (Vulpes lagopus), a small mammalian predator endemic to northern tundra areas, is able to exploit different resources in the context of varying tundra ecosystems. Although generally widespread, ...
    • Warming and CO2 enhance arctic heterotrophic microbial activity 

      Vaqué, Dolors; Lara, Elena; Arrieta, Jesús M.; Holding, Johnna; Sa, Elisabet L; Hendriks, Iris E.; Coello-Camba, Alexandra; Alvarez, Marta; Agusti, Susana; Wassmann, Paul; Duarte, Carlos M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-20)
      Ocean acidification and warming are two main consequences of climate change that can directly affect biological and ecosystem processes in marine habitats. The Arctic Ocean is the region of the world experiencing climate change at the steepest rate compared with other latitudes. Since marine planktonic microorganisms play a key role in the biogeochemical cycles in the ocean it is crucial to ...
    • Warming of Atlantic Water in two west Spitsbergen fjords over the last century (1912-2009) 

      Pavlov, Alexey K.; Tverberg, Vigdis; Ivanov, Boris; Nilsen, Frank; Falk-Petersen, Stig; Granskog, Mats A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      The recently observed warming of west Spitsbergen fjords has led to anomalous sea-ice conditions and has implications for the marine ecosystem. We investigated long-term trends of maximum temperature of AtlanticWater (AW) in two west Spitsbergen fjords. The data set is composed of more than 400 oceanographic stations for Isfjorden and Grønfjorden (78.18N), spanning from 1876 to 2009. Trends ...
    • 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 ...
    • Waters that matter: How human-environment relations are changing in high-Arctic Svalbard 

      Sokolickova, Zdenka; Ramirez Hincapié, Esteban; Zhang, Jasmine; Lennert, Ann Eileen; Löf, Annette; van der Wal, René (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-20)
      There is scientific consensus that the archipelago of Svalbard is warming up faster than other parts of the planet. People who live in or regularly visit this part of the European high Arctic observe and experience these changes in a subjective and relational manner. This article illustrates how perceptions of environmental change are enmeshed with our ways of interacting with water(s) and dwelling ...
    • A way forward with eco evo devo: an extended theory of resource polymorphism with postglacial fishes as model systems 

      Skulason, Skuli; Parsons, Kevin J; Svanback, Richard; Räsänen, Katja; Ferguson, Moira M; Adams, Colin Ean; Amundsen, Per-Arne; Bartels, Pia; Bean, Colin W.; Boughman, Janette W.; Englund, Göran; Gudbrandsson, Johannes; Hooker, Oliver E.; Hudson, Alan G; Kahilainen, Kimmo Kalevi; Knudsen, Rune; Kristjánsson, Bjarni Kr.; Leblanc, Camille A-L; Jonsson, Zophonias; Ohlund, Gunnar; Smith, Carl; Snorrason, Sigurdur S (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-19)
      A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo) on an equal footing, is needed to understand the ...
    • 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 ...
    • Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean 

      Polyakov, Igor V.; Rippeth, Tom; Fer, Ilker; Alkire, Matthew B.; Carmack, Eddy; Ingvaldsen, Randi Brunvær; Ivanov, Vladimir V.; Janout, Markus; Lind, Sigrid; Padman, Laurie; Pnyushkov, Andrey V.; Rember, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-20)
      A 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened ...
    • Webcams as a Remote Tool for Eco-ethological Research: A Study on the Alpine Chough 

      Vallino, Cristina; Yoccoz, Nigel; Rolando, Antonio; Delestrade, Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-02)
      Methods and devices specifically created for remote animal surveys and monitoring are becoming increasingly popular and effective. However, remote devices are also widely used in our societies for different, not scientific, goals. Ski resorts in the European Alps, for instance, use webcams to share panoramic views and promote themselves in the industry of winter recreational activities. We tested ...
    • Welcome to the Family: Identification of the NAD+ Transporter of Animal Mitochondria as Member of the Solute Carrier Family SLC25 

      Monnè, Magnus; Nikiforov, Andrey; Heiland, Ines; Agrimi, Gennaro; Ziegler, Mathias; Palmieri, Ferdinando (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-14)
      Subcellular compartmentation is a fundamental property of eukaryotic cells. Communication and metabolic and regulatory interconnectivity between organelles require that solutes can be transported across their surrounding membranes. Indeed, in mammals, there are hundreds of genes encoding solute carriers (SLCs) which mediate the selective transport of molecules such as nucleotides, amino acids, ...
    • What are the effects of herbivore diversity on tundra ecosystems? A systematic review protocol 

      Barrio, Isabel C.; Barbero-Palacios, Laura; Kaarlejärvi, Elina; Speed, James David Mervyn; Heiðmarsson, Starri; Hik, David S.; Soininen, Eeva M (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-31)
      Background: Changes in the diversity of herbivore communities can strongly infuence the functioning of northern ecosystems. Diferent herbivores have diferent impacts on ecosystems because of diferences in their diets, behaviour and energy requirements. The combined efects of diferent herbivores can in some cases compensate each other but lead to stronger directional changes elsewhere. However, ...
    • What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation? A systematic review protocol 

      Bernes, Claes; Bråthen, Kari Anne; Forbes, Bruce C.; Hofgaard, Annika; Moen, Jon; Speed, James David Mervyn (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Abstract Background: Reindeer and caribou (both belonging to the species Rangifer tarandus L.) are among the most important large herbivores in Eurasia’s and North America’s arctic, alpine and boreal zones. In Sweden, the impact of reindeer grazing on arctic and alpine vegetation has recently been re-evaluated. In the 1990s, records of grazing-related vegetation degradation helped to form a ...
    • What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation? A systematic review 

      Bernes, Claes; Bråthen, Kari Anne; Forbes, Bruce C.; Speed, James David Mervyn; Moen, Jon (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-23)
      Background: The reindeer (or caribou, Rangifer tarandus L.) has a natural range extending over much of Eurasia’s and North America’s arctic, alpine and boreal zones, yet its impact on vegetation is still unclear. This lack of a common understanding hampers both the management of wild and semi-domesticated reindeer populations and the preservation of biodiversity. To achieve a common platform, we ...
    • What Do the IUCN Categories Really Protect? A Case from the Alpine Regions in Spain? 

      Muñoz, Lorena; Hausner, Vera Helene (Conference object; Konferansebidrag, 2012)
      The protected area (PA) coverage is used as an indicator of biodiversity protection worldwide. The effectiveness of using PAs as indicators has been questioned due to the diversity of designations included in such measures, especially those PAs established for other purposes than biodiversity protection. Although international standards have been developed by the International Union for Conservation ...
    • What Do the IUCN Categories Really Protect? A Case Study of the Alpine Regions in Spain. 

      Muñoz, Lorena; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Protected area (PA) coverage is used as an indicator of biodiversity protection worldwide. The effectiveness of using PAs as indicators has been questioned due to the diversity of categories encompassed by such designations, especially in PAs established for purposes other than biodiversity protection. Although international standards have been developed by the International Union for Conservation ...
    • What feeds the benthos in the Arctic basins? Assembling a carbon budget for the deep Arctic ocean 

      Wiedmann, Ingrid; Ershova, Elizaveta; Bluhm, Bodil; Nöthig, Eva-Maria; Kosobokova, Ksenia; Boetius, Antje; Gradinger, Rolf R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-16)
      Half of the Arctic Ocean is deep sea (>1000 m), and this area is currently transitioning from being permanently ice-covered to being seasonally ice-free. Despite these drastic changes, it remains unclear how organisms are distributed in the deep Arctic basins, and particularly what feeds them. Here, we summarize data on auto- and heterotrophic organisms in the benthic, pelagic, and sympagic realm ...