Viser treff 1521-1540 av 2078

    • Hidden in the darkness of the Polar night: A first glimpse into winter migration of the Svalbard rock ptarmigan 

      Fuglei, Eva; Blanchet, Marie-Anne; Unander, Sigmund; Ims, Rolf Anker; Pedersen, Åshild Ønvik (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-05)
      Among many unknown aspects of the Svalbard rock ptarmigan’s biology is whether the birds migrate seasonally within the Svalbard archipelago. Visual observations in spring and fall have indicated that they could perform long-range migration, a behaviour that would allow them to track seasonal shifts in suitable feeding areas. However, the movement patterns and habitat use of the Svalbard rock ...
    • Behavioural Responses of Moulting Barnacle Geese to Experimental Helicopter Noise and a Predator 

      Tyler, Nicholas J. C.; Jacobsen, Karl-Otto; Blix, Arnoldus S (Journal article; Tidsskriftartikkel; Peer reviewed, 2016)
      The response of animals to anthropogenic noise can be aggravated by lack of familiarity with its auditory pattern and also by nervousness characteristic of particular phases of their life cycle. Both conditions apply in the Arctic where human activity is highly localised and field operations, being largely restricted to summer, coincide with the period when animals produce and nurse offspring and, ...
    • On the use of the HUGIN 1000 HUS Autonomous Underwater Vehicle for high resolution zooplankton measurements 

      Pedersen, Ole Petter; Gaardsted, Frank; Lågstad, Petter Arthur; Tande, Kurt Steinar (Journal article; Tidsskriftartikkel; Peer reviewed, 2010)
      This paper evaluates and tests the HUGIN 1000 HUS AUV as a carrier platform for the Laser Optical Plankton Counter (LOPC). The LOPC was mounted outside on top of the carrier platform, and the tests confirm that this concept did not create turbulence and zooplankton avoidance. A negligible velocity difference between the flow passing through the sampling tube and the AUV speed was detected. The ...
    • 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 ...
    • Velferdskriterier i reindriften 

      Jørgensen, Grete Helen Meisfjord; Mejdell, Cecilie Marie; Stubsjøen, Solveig Marie; Ozkan, Seyda; Rødbotten, Rune; Bårdsen, Bård-Jørgen; Rødven, Rolf (Research report; Forskningsrapport, 2017-06-07)
      Formålet med prosjektet var å identifisere ulike faktorer som kunne påvirke velferd hos tamrein, og som kunne implementeres i produksjonssystemene, på beite, i gjerdet, på slakteriet, gjennom produktmerking og fremtidige kvalitetssikringssystemer. I den senere tid har det vært et økt fokus på dyrehelse og -velferd i reindrifta. Det har for eksempel vært et fokus på lave slaktevekter, spesielt i ...
    • Scientific opinion on chronic wasting disease (CWD) in cervids 

      Ricci, A; Allende, A; Bolton, D.; Chemaly, M; Davies, R; Fernandez Escamez, PS; Girones, R; Herman, L; Koutsoumanis, Kostas; Lindqvist, R; Nørrung, Birgit; Robertson, Lucy; Sanaa, Moez; Skandamis, Panagiotis; Snary, Emma; Speybroeck, Niko; Ter Kuile, Benno; Threlfall, john; Wahlström, Helene; Benestad, Sylvie Lafond; Gavier-Widén, Dolores; Miller, MW; Ru, Giuseppe; Telling, GC; Tryland, Morten; Ortiz Pelaez, A; Simmons, Marion M (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-18)
      In April and May of 2016, Norway confirmed two cases of chronic wasting disease (CWD) in a wild reindeer and a wild moose, respectively. In the light of this emerging issue, the European Commission requested EFSA to recommend surveillance activities and, if necessary, additional animal health risk-based measures to prevent the introduction of the disease and the spread into/within the EU, specifically ...
    • Tresatt impediment og livsløpstrær av osp på hogstflater. Effektive tiltak for artsmangfoldet i norsk skog? 

      Sverdrup-Thygeson, Anne; Ims, Rolf Anker (Research report; Forskningsrapport, 2005-07)
      Skogbruket legger ned betydelige ressurser i form av arbeid og kapital for å ta hensyn til biologisk mangfold. Det er av stor betydning for skogbrukets økonomi og konkurranseevne at disse ressursene benyttes slik at man får best mulig bevaring av biologisk mangfold per krone. Rapporten omhandler to ulike delprosjekter som har vært gjennomført i forbindelse med Forskningsrådets prosjekt ...
    • Konflikter mellom ærfugl og blåskjelldyrking 

      Erikstad, Kjell E; Bustnes, Jan Ove; Rikardsen, Audun; Jacobsen, Karl-Otto; Strann, Karl Birger; Johnsen, Trond Vidar; Reiertsen, Tone (Research report; Forskningsrapport, 2006-01)
      Oppdrett av blåskjell har i de senere år økt sterkt i omfang i Norge, men kunnskapen om de økologiske konsekvensene av virksomheten er meget begrenset. Et betydelig problem som har oppstått i denne forbindelse er predasjon fra fugl, og da særlig ærfugl. Dette har klare negative konsekvenser for lønnsomheten, samt representerer et kunstig habitat og mulige negative påvirkninger for fugl. Bedre ...
    • 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. ...
    • Røye som langtidsvert og smittereservoar for Gyrodactylus salaris i Skibotnelva i Troms 

      Kristoffersen, Roar; Rikardsen, Audun; Winger, Anja; Adolfsen, Pål; Knudsen, Rune (Research report; Forskningsrapport, 2005-03)
      Skibotnelva i Troms var lenge det eneste vassdraget i våre to nordligste fylker med infeksjon av fiskeparasitten Gyrodactylus salaris. Parasitten ble første gang påvist i 1979, og to rotenonbehandlinger i den lakseførende delen (i 1988 og 1995) har vært mislykkede. Di-rektoratet for naturforvaltning vurderer bygging av langtidssperre som et av flere aktuelle utryddingstiltak i Skibotnelva. Imidlertid ...
    • Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations 

      Berteaux, Dominique; Thierry, Anne-Mathilde; Alisauskas, Ray; Angerbjörn, Anders; Buchel, Eric; Doronina, Liliya; Ehrich, Dorothee; Eide, Nina Elisabeth; Erlandsson, Rasmus; Flagstad, Øystein; Fuglei, Eva; Gilg, Olivier; Golstman, Mikhail; Henttonen, Heikki; Ims, Rolf Anker; Killengreen, Siw Turid; Kondratyev, Alexander V.; Kruchenkova, Elena; Kruckenberg, Helmut; Kulikova, Olga; Landa, Arild Magne; Lang, Johannes; Menyushina, Irina; Mikhnevich, Julia; Niemimaa, Jukka; Norén, Karin; Ollila, Tuomo; Ovsyanikov, Nikita; Pokrovskaya, Liya; Pokrovsky, Ivan G.; Rodnikova, Anna Y.; Roth, James D.; Sabard, Brigitte; Samelius, Gustaf; Schmidt, Niels-Martin; Sittler, Benoit; Sokolov, Aleksandr A.; Sokolova, Natalya A.; Stickney, Alice; Unnsteinsdóttir, Ester Rut; White, Paula A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-16)
      The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide ...
    • Impacts of Early Life Stress on the Methylome and Transcriptome of Atlantic Salmon 

      Moghadam, Hooman; Johnsen, Hanne; Robinson, Nick; Andersen, Øivind; Jørgensen, Even Hjalmar; Johnsen, Helge K.; Bæhr, Vegar J.; Tveiten, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-10)
      Exposure to environmental stressors during early-life stages can change the rate and timing of various developmental processes. Epigenetic marks affecting transcriptional regulation can be altered by such environmental stimuli. To assess how stress might affect the methylome and transcriptome in salmon, fish were treated using cold-shock and air-exposure from the eye-stage until start-feeding. ...
    • Naturmangfoldlovens virkninger i kommunene. En gjennomgang av kommunale erfaringer med loven 

      Andersen, Oddgeir; Bay-Larsen, Ingrid Agathe; Øian, Hogne; Fangel, Kirstin (Research report; Forskningsrapport, 2013-11-04)
      Denne studien skal gi svar på hvilke erfaringer kommunene har gjort seg etter at naturmang-foldloven (NML) trådte i kraft. Rapporten baseres på en internettbasert spørreundersøkelse til kommunene og personlige intervjuer og gruppeintervjuer (i case studiene). To verneområdes-tyrer ble valgt ut for case-studier: (1) Dovre-Sunndalsfjella og (2) Midtre Nordland nasjonal-parkstyre. Saker som er vedtatt ...
    • Turbulent heat and momentum fluxes in the upper ocean under Arctic sea ice 

      Peterson, Algot Kristoffer; Fer, Ilker; McPhee, Miles G.; Randelhoff, Achim (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-25)
      We report observations of heat and momentum fluxes measured in the ice-ocean boundary layer from four drift stations between January and June 2015, covering from the typical Arctic basin conditions in the Nansen Basin to energetic spots of interaction with the warm Atlantic Water branches near the Yermak Plateau and over the North Spitsbergen slope. A wide range of oceanic turbulent heat flux values ...
    • Lipid content and fatty acid composition of Porosira glacialis and Attheya longicornis in response to carbon dioxide (CO2) aeration 

      Artamonova, Elena; Vasskog, Terje; Eilertsen, Hans Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-18)
      In the current study two novel psychrophilic diatoms Porosira glacialis and Attheya longicornis were tested for suitability to CO2 mitigation coupled with production of the physiologically requisite omega± 3 fatty acids. This study is in line with the worldwide conducted research aimed at applying biorefinery concept to heavy polluting industries. Since the production of algal high value compounds, ...
    • Fish populations, gill net catches and gill net selectivity in the Lower Orange River, Namibia, from 1995 to 2001 

      Næsje, Tor; Hay, Clinton J.; Nickanor, Nande; Koekemoer, Johan; Strand, Rita; Thorstad, Eva Bonsak (Research report; Forskningsrapport, 2007-01)
      The Orange River: The lower part of the Orange River forms the border between Namibia and South Africa from the mouth of the river and 580 km upstream. The river origins in the Lesotho Highlands, and runs for approximately 2300 km from the source to the Orange River Mouth at Oranjemund (Namibia) and Alexander Bay (South Africa), where it discharges into the Atlantic Ocean. The total Orange ...
    • Arctic greening from warming promotes declines in caribou populations 

      Fauchald, Per; Park, Taejin; Tømmervik, Hans; Myneni, Ranga B.; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-26)
      The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced changes on the adjacent caribou summer ranges, outperforming ...
    • Cervid herpesvirus 2 and not Moraxella bovoculi caused keratoconjunctivitis in experimentally inoculated semi-domesticated Eurasian tundra reindeer 

      Tryland, Morten; Sanchez Romano, Javier; Marcin, Nina; Nymo, Ingebjørg Helena; Josefsen, Terje Domaas; Sørensen, Karen Kristine; Mørk, Torill (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-24)
      Background: Infectious keratoconjunctivitis (IKC) is a transmissible disease in semi-domesticated Eurasian reindeer (Rangifer tarandus tarandus). It is regarded as multifactorial and a single causative pathogen has not yet been identified. From clinical outbreaks we have previously identified Cervid herpesvirus 2 (CvHV2) and Moraxella bovoculi as candidates for experimental investigations. Eighteen ...
    • Epibenthic fauna in Balsfjord. Potential food for the invasive red king crab (Paralithodes camtschaticus) with special attention to the deposit-feeding sea star Ctenodiscus crispatus 

      Tranang, Caroline Aas (Master thesis; Mastergradsoppgave, 2017-05-12)
      After its introduction to the Barents Sea in the 1960’s, the red king crab Paralithodes camtschaticus has become an invasive species in northern Norwegian fjords and it is continuing to spread southward along the coast. Due to its negative effects on native benthic fauna through predation, establishing baseline studies in undisturbed fjords is important. In this study, the soft-bottom epibenthic ...
    • Do diet of long rough dab (Hippoglossoides platessoides) differ between fjords with and without red king crab (Paralithodes camtschaticus)? A study of summer diet 

      Kiærbech, Kristoffer (Master thesis; Mastergradsoppgave, 2017-05-15)
      The purpose of this study is to describe the diet of long rough dab in three different fjords with and without red king crab. The hypothesis is that red king crab are influencing the diet and possible also growth of long rough dab. By the applying objectives it is assumed to give an answer to if red king crab is influencing different aspects of the diet and growth in long rough dab. By the ...