Blar i Department of Biological Sciences på forfatter "Varpe, Øystein"

Viser treff 1-20 av 23

    • Aggregations of foraging black guillemots (Cepphus grylle) at a sea-ice edge in front of a tidewater glacier 

      Varpe, Øystein; Gabrielsen, Geir W. (Journal article; Peer reviewed, 2022)
      Seabirds in cold biomes sometimes aggregate near glacier fronts and at sea-ice edges to forage. In this note, we report on large aggregations of black guillemots (Cepphus grylle) at the edge of sea ice in front of the ...

    • Capturing big fisheries data: Integrating fishers’ knowledge in a web-based decision support tool 

      Kelly, Cian; Michelsen, Finn Are; Reite, Karl Johan; Kolding, Jeppe; Varpe, Øystein; Prytz Berset, Are; Alver, Morten (Journal article; Peer reviewed, 2022-12-12)
      There is increasing interest in utilizing fishers’ knowledge to better understand the marine environment, given the spatial extent and temporal resolution of fishing vessel operations. Furthermore, fishers’ knowledge is ...

    • Centennial relationships between ocean temperature and Atlantic puffin production reveal shifting decennial trends 

      Hansen, Erpur S.; Sandvik, Hanno; Erikstad, Kjell E.; Yoccoz, Nigel; Anker-Nilssen, Tycho; Bader, Jürgen; Descamps, Sebastien; Hodges, Kevin; Mesquita, Michel d. S.; Reiertsen, Tone Kristin; Varpe, Øystein (Journal article; Peer reviewed, 2021)
      The current warming of the oceans has been shown to have detrimental effects for a number of species. An understanding of the underlying mechanisms may be hampered by the non-linearity and non-stationarity of the relationships ...

    • Developing common protocols to measure tundra herbivory across spatial scales 

      Barrio, Isabel C.; Ehrich, Dorothee; Soininen, Eeva M; Ravolainen, Virve; Bueno, C. G.; Gilg, Olivier; Koltz, Amanda; Speed, James David Mervyn; Hik, David S.; Mörsdorf, M.; Alatalo, Juha M.; Angerbjørn, A.; Bêty, Joël; Bollache, L.; Boulanger-Lapointe, N.; Brown, G. S.; Eischeid, Isabell; Giroux, M. A.; Hajek, T.; Hansen, Brage Bremset; Hofhius, S. P.; Lamarre, J.-F.; Lang, J.; Latty, C.; Lecomte, N.; Macek, P.; McKinnon, L.; Myers-Smith, I. H.; Pedersen, Åshild Ønvik; Prevey, J. S.; Roth, J. D.; Saalfeld, S. T.; Schmidt, N. M.; Smith, P.; Sokolov, A.; Sokolova, N.; Stolz, C.; van Bemmelen, R.; Varpe, Øystein; Woodard, P. F.; Jonsdottir, I. S. (Journal article; Peer reviewed, 2021)
      Understanding and predicting large-scale ecological responses to global environmental change requires comparative studies across geographic scales with coordinated efforts and standardized methodologies. We designed, ...

    • Diets of gadoid fish in Arctic waters of Svalbard fjords during the polar night 

      Larsen, Lars-Henrik; Cusa, Marine Lure Joana; Eglund-Newby, Sam; Berge, Jørgen; Renaud, Paul Eric; Varpe, Øystein; Geoffroy, Maxime; Falk-Petersen, Stig (Journal article; Peer reviewed, 2023)
      As the climate warms, boreal fish species are expected to expand into the Arctic domain. Though water temperature is an important factor driving expansion of aquatic species, other variables may play a critical role in ...

    • Eight decades of adaptive changes in herring reproductive investment: the joint effect of environment and exploitation 

      Claireaux, Marion; dos Santos Schmidt, Thassya Christina; Olsen, Esben Moland; Slotte, Aril; Varpe, Øystein; Heino, Mikko Petteri; Enberg, Katja (Journal article; Peer reviewed, 2021)
      Reproductive investment is a central trait for population dynamics and productivity. Fishing and environmental variations are major drivers affecting population structure, dynamics, and adaptation of life-history and ...

    • Energy content of krill and amphipods in the Barents Sea from summer to winter: variation across species and size 

      Nowicki, Robynne; Borgå, Katrine; Gabrielsen, Geir W.; Varpe, Øystein (Journal article; Peer reviewed, 2023)
      Arctic zooplankton develop large energy reserves, as an adaptation to strong seasonality, making them valuable prey items. We quantified the energy content (kJ g−1 dry weight) of abundant krill (arcto-boreal, Thysanoessa ...

    • Foraging tactics in dynamic sea-ice habitats affect individual state in a long-ranging seabird 

      Tarroux, Arnaud; Cherel, Yves; Fauchald, Per; Kato, Akiko; Love, Oliver P.; Ropert-Coudert, Yan; Spreen, Gunnar; Varpe, Øystein; Weimerskirch, Henri; Yoccoz, Nigel; Zahn, Sandrine; Descamps, Sebastien (Journal article; Peer reviewed, 2020)
      1. Individual heterogeneity in diet and foraging behaviour is common in wild animal populations, and can be a strong determinant of how populations respond to environmental changes. Within populations, variation in foraging ...

    • 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; Peer reviewed, 2022)
      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 ...

    • In the dark: a review of ecosystem processes during the Arctic polar night 

      Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.; Johnsen, Geir; Seuthe, Lena; Weslawski, Jan Marcin; Leu, Eva; Moline, Mark A.; Nahrgang, Jasmine; Søreide, Janne; Varpe, Øystein; Lønne, Ole Jørgen; Daase, Malin; Falk-Petersen, Stig (Peer reviewed; Journal article, 2015-08-28)
      Several recent lines of evidence indicate that the polar night is key to understanding Arctic marine ecosystems. First, the polar night is not a period void of biological activity even though primary production is close ...

    • A marine zooplankton community vertically structured by light across diel to interannual timescales 

      Hobbs, Laura; Banas, Neil S.; Cohen, Jonathan H.; Cottier, Finlo Robert; Berge, Jørgen; Varpe, Øystein (Journal article; Peer reviewed, 2021)
      The predation risk of many aquatic taxa is dominated by visually searching predators, commonly a function of ambient light. Several studies propose that changes in visual predation will become a major climate-change impact ...

    • Nesting synchrony and clutch size in migratory birds: Capital versus income breeding determines responses to variable spring onset 

      Ejsmond, Anna; Forchhammer, Mads; Varpe, Øystein; Jónsson, Jón Einar; Jørgensen, Christian (Journal article; Peer reviewed, 2021)
      Synchronous reproduction of birds has often been explained by benefits from nesting together, but this concept fails to explain observed intraspecific variation and climate-mediated changes of breeding synchrony. Here, we ...

    • Nutrient fuxes from an Arctic seabird colony to the adjacent coastal marine ecosystem 

      Finne, Eirik Aasmo; Varpe, Øystein; Durant, Joël; Gabrielsen, Geir W.; Poste, Amanda (Journal article; Peer reviewed, 2022)
      Seabirds are important vectors for nutrient transfer across ecosystem boundaries. In this seasonal study, we evaluate the impact of an Arctic colony (Alkhornet, Svalbard) of Black-legged Kittiwakes (Rissa tridactyla) and ...

    • Pelagic organisms avoid white, blue, and red artificial light from scientific instruments 

      Geoffroy, Maxime; Langbehn, Tom; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.; Berge, Jørgen (Journal article; Peer reviewed, 2021)
      In situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. ...

    • Predator–prey interactions in the Arctic: DNA metabarcoding reveals that nestling diet of snow buntings reflects arthropod seasonality 

      Stolz, Christian; Varpe, Øystein; Ims, Rolf Anker; Sandercock, Brett Kevin; Stokke, Bård Gunnar; Fossøy, Frode (Journal article; Peer reviewed, 2023)
      Tundra arthropods are of considerable ecological importance as a seasonal food source for many arctic-breeding birds. Dietary composition and food preferences are rarely known, complicating assessments of ecological ...

    • Sea-ice loss boosts visual search: fish foraging and changing pelagic interactions in polar oceans 

      Langbehn, Tom; Varpe, Øystein (Peer reviewed; Journal article, 2017)
      Light is a central driver of biological processes and systems. Receding sea ice changes the lightscape of high-latitude oceans and more light will penetrate into the sea. This affects bottom-up control through primary ...

    • Seasonal pollutant levels in littoral high-Arctic amphipods in relation to food sources and terrestrial run-off 

      Skogsberg, Stina Linnea Emelie; Mcgovern, Maeve; Poste, Amanda; Jonsson, Sofi; Arts, Michael T.; Varpe, Øystein; Borgå, Katrine (Journal article; Peer reviewed, 2022)
      Increasing terrestrial run-off from melting glaciers and thawing permafrost to Arctic coastal areas is expected to facilitate re-mobilization of stored legacy persistent organic pollutants (POPs) and mercury (Hg), potentially ...

    • Strengthening the evidence base for temperature-mediated phenological asynchrony and its impacts 

      Samplonius, Jelmer; Atkinson, Angus; Hassall, Christopher; Keogan, Katherine; Thackeray, Stephen J.; Assmann, Jakob J.; Burgess, Malcolm D.; Macphie, Kirsty H; Pearce-Higgins, James W.; Simmonds, Emily Grace; Johansson, Jacob; Varpe, Øystein; Weir, James C; Childs, Dylan Z.; Cole, Ella F.; Daunt, Francis; Hart, Tom; Lewis, Owen T.; Pettorelli, Nathalie; Sheldon, Ben C.; Phillimore, Albert B. (Journal article; Peer reviewed, 2021)
      Climate warming has caused the seasonal timing of many components of ecological food chains to advance. In the context of trophic interactions, the match–mismatch hypothesis postulates that differential shifts can lead to ...

    • 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; Peer reviewed, 2020)
      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 ...

    • Timing of Calanus finmarchicus diapause in stochastic environments 

      Bandara, Kanchana; Varpe, Øystein; Maps, Frédéric; Ji, Rubao; Eiane, Ketil; Tverberg, Vigdis (Journal article; Peer reviewed, 2021)
      In environments with strong seasonality, many herbivorous zooplankton remain active only during the productive season and undergo a period of inactivity and suppressed development termed ‘diapause’ during the unproductive ...