Blar i forfatter Fakultet for biovitenskap, fiskeri og økonomi "Aars, Jon"

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    • An Arctic predator–prey system in flux: climate change impacts on coastal space use by polar bears and ringed seals 

      Hamilton, Charmain Danielle; Kovacs, Kit; Ims, Rolf Anker; Aars, Jon; Lydersen, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-17)
      <p>1. Climate change is impacting different species at different rates, leading to alterations in biological interactions with ramifications for wider ecosystem functioning. Understanding these alterations can help improve predictive capacity and inform management efforts designed to mitigate against negative impacts.</p> <p>2. We investigated how the movement and space use patterns of polar bears ...

    • Choose your poison – Space-use strategy influences pollutant exposure in Barents Sea polar bears 

      Tartu, Sabrina; Aars, Jon; Andersen, Magnus; Polder, Anuschka; Bourgeon, Sophie; Merkel, Benjamin; Lowther, Andrew D.; Bytingsvik, Jenny; Welker, Jeffrey Martin; Derocher, Andrew E.; Jenssen, Bjørn Munro; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)
      Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000–2014, n = 152). First, ...

    • Diet and metabolic state are the main factors determining concentrations of perfluoroalkyl substances in female polar bears from Svalbard 

      Tartu, Sabrina; Bourgeon, Sophie; Aars, Jon; Andersen, Magnus; Lone, Karen; Jenssen, Bjørn Munro; Polder, Anuschka; Thiemann, Gregory W.; Torget, Vidar; Welker, Jeffrey Martin; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-03)
      Perfluoroalkyl substances (PFASs) have been detected in organisms worldwide, including Polar Regions. The polar bear (Ursus maritimus), the top predator of Arctic marine ecosystems, accumulates high concentrations of PFASs, which may be harmful to their health. The aim of this study was to investigate which factors (habitat quality, season, year, diet, metabolic state [i.e. feeding/fasting], breeding ...

    • Geographical area and life history traits influence diet in an Arctic marine predator 

      Tartu, Sabrina; Bourgeon, Sophie; Aars, Jon; Andersen, Magnus; Ehrich, Dorothee; Thiemann, Gregory W.; Welker, Jeffrey Martin; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-19)
      Global changes are thought to affect most Arctic species, yet some populations are more at risk. Today, the Barents Sea ecoregion is suffering the strongest sea ice retreat ever measured; and these changes are suspected to modify food access and thus diet of several species. Biochemical diet tracers enable investigation of diet in species such as polar bears (Ursus maritimus). We examined ...

    • Marine mammal hotspots across the circumpolar Arctic 

      Hamilton, Charmain D.; Lydersen, Christian; Aars, Jon; Acquarone, Mario; Atwood, Todd; Baylis, Alastair; Biuw, Martin; Boltunov, Andrei N.; Born, Erik W.; Boveng, Peter; Brown, Tanya M.; Cameron, Michael; Citta, John; Crawford, Justin; Dietz, Rune; Elias, Jim; Ferguson, Steven H.; Fisk, Aaron; Folkow, Lars; Frost, Kathryn J.; Glazov, Dmitri M.; Granquist, Sandra M.; Gryba, Rowenna; Harwood, Lois; Haug, Tore; Heide-Jørgensen, Mads Peter; Hussey, Nigel E.; Kalinek, Jimmy; Laidre, Kristin L.; Litovka, Dennis I.; London, Josh M.; Loseto, Lisa L.; MacPhee, Shannon; Marcoux, Marianne; Matthews, Cory J. D.; Nilssen, Kjell Tormod; Nordøy, Erling Sverre; O’Corry-Crowe, Greg; Øien, Nils Inge; Olsen, Morten Tange; Quakenbush, Lori; Rosing-Asvid, Aqqalu; Semenova, Varvara; Shelden, Kim E. W.; Shpak, Olga V.; Stenson, Garry; Storrie, Luke; Sveegaard, Signe; Teilmann, Jonas; Ugarte, Fernando; Von Duyke, Andrew L.; Watt, Cortney; Wiig, Øystein; Wilson, Ryan R.; Yurkowski, David J.; Kovacs, Kit M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-11)
      Aim: Identify hotspots and areas of high species richness for Arctic marine mammals.<p><p> Location: Circumpolar Arctic. <p>Methods: A total of 2115 biologging devices were deployed on marine mammals from 13 species in the Arctic from 2005 to 2019. Getis-Ord Gi* hotspots were calculated based on the number of individuals in grid cells for each species and for phyloge-netic groups (nine pinnipeds, ...

    • Marine mammal hotspots in the Greenland and Barents Seas 

      Hamilton, Charmain Danielle; Lydersen, Christian; Aars, Jon; Biuw, Martin; Boltunov, Andrei; Born, Erik W.; Dietz, Rune; Folkow, Lars; Glazov, Dmitry M.; Haug, Tore; Heide-Jørgensen, Mads-Peter; Kettemer, Lisa Elena; Laidre, Kristin L.; Øien, Nils Inge; Nordøy, Erling Sverre; Rikardsen, Audun H.; Rosing-Asvid, Aqqalu; Semenova, Varvara; Shpak, Olga V.; Sveegaard, Signe; Ugarte, Fernando; Wiig, Øystein; Kovacs, Kit M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-04)
      Environmental change and increasing levels of human activity are threats to marine mam- mals in the Arctic. Identifying marine mammal hot - spots and areas of high species richness are essential to help guide management and conservation efforts. Herein, space use based on biotelemetric tracking devices deployed on 13 species (ringed seal <i>Pusa hispida</i>, bearded seal <i>Erignathus ...

    • Modeling the demography of species providing extended parental care: A capture–recapture multievent model with a case study on polar bears (Ursus maritimus) 

      Cubaynes, Sarah; Aars, Jon; Yoccoz, Nigel; Pradel, Roger; Wiig, Øystein; Ims, Rolf Anker; Gimenez, Olivier (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-10)
      <ol> <li>In species providing extended parental care, one or both parents care for altricial young over a period including more than one breeding season. We expect large parental investment and long-term dependency within family units to cause high variability in life trajectories among individuals with complex consequences at the population level. So far, models for estimating demographic ...

    • Niches of marine mammals in the European Arctic 

      MacKenzie, Kirsteen M.; Lydersen, Christian; Haug, Tore; Routti, Heli Anna Irmeli; Aars, Jon; Andvik, Clare Margaret; Borgå, Katrine; Fisk, A.T.; Meier, Sonnich; Biuw, Martin; Lowther, Andrew; Lindstrøm, Ulf Ove; Kovacs, Kit M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-11)
      The Arctic is warming rapidly, with concomitant sea ice losses and ecosystem changes. The animals most vulnerable to Arctic food web changes are long-lived and slow-growing such as marine mammals, which may not be able to adapt rapidly enough to respond to changes in their resource bases. To determine the current extent and sources of these resource bases, we examined isotopic and trophic niches ...

    • Occurrence of emerging brominated flame retardants and organophosphate esters in marine wildlife from the Norwegian Arctic 

      Lippold, Anna; Harju, Mikael; Aars, Jon; Blévin, Pierre; Bytingsvik, Jenny; Gabrielsen, Geir W.; Kovacs, Kit M.; Lyche, Jan Ludwig; Lydersen, Christian; Rikardsen, Audun H.; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-10)
      To understand the exposure and potential sources of emerging brominated flame retardants (EBFR) and organophosphate esters (OPEs) in marine wildlife from the Norwegian Arctic, we investigated concentrations of EBFRs in 157 tissue samples from nine species of marine vertebrates and OPEs in 34 samples from three whale species. The samples, collected from a wide range of species with contrasting ...

    • Pelagic vs coastal - Key drivers of pollutant levels in Barents Sea polar bears with contrasted space-use strategies 

      Blévin, Pierre; Aars, Jon; Andersen, Magnus; Blanchet, Marie-Anne; Hanssen, Linda; Herzke, Dorte; Jeffreys, Rachel M.; Nordøy, Erling Sverre; Pinzone, Marianna; de la Vega, Camille; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-11)
      In the Barents Sea, pelagic and coastal polar bears are facing various ecological challenges that may explain the difference in their pollutant levels. We measured polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers in fat, and perfluoroalkyl substances in plasma in pelagic and coastal adult female polar bears with similar body condition. We studied polar bear feeding ...

    • Potentiation of ecological factors on the disruption of thyroid hormones by organo-halogenated contaminants in female polar bears (Ursus maritimus) from the Barents Sea. 

      Bourgeon, Sophie; Riemer, Astrid Kolind; Tartu, Sabrina; Aars, Jon; Polder, Anuschka; Jenssen, Bjørn Munro; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-11)
      As apex predators, polar bears (Ursus maritimus) are among the most heavily polluted organisms in the Arctic. In addition to this anthropogenic stressor, climate warming has been shown to negatively affect their body condition, reproductive output and survival. Among potential underlying physiological mechanisms, thyroid hormones (THs), which control thermoregulation, metabolism and reproduction, ...

    • A risk assessment review of mercury exposure in Arctic marine and terrestrial mammals 

      Dietz, Rune; Letcher, Robert J.; Aars, Jon; Andersen, Magnus; Boltunov, Andrei; Born, Erik W.; Ciesielski, Tomasz Maciej; Das, Krishna; Dastnai, Sam; Derocher, Andrew E.; Desforges, Jean-Pierre; Eulaers, Igor; Ferguson, Steve; Hallanger, Ingeborg G.; Heide-Jørgensen, Mads P.; Heimbürger-Boavida, Lars-Eric; Hoekstra, Paul F.; Jenssen, Bjørn Munro; Kohler, Stephen Gustav; Larsen, Martin M.; Lindstrøm, Ulf Ove; Lippold, Anna; Morris, Adam; Nabe-Nielsen, Jacob; Nielsen, Nynne H.; Peacock, Elizabeth E.; Rigét, Frank F.; Rosing-Asvid, Aqqalu; Routti, Heli Anna Irmeli; Siebert, Ursula; Stenson, Garry; Stern, Gary; Strand, Jakob; Søndergaard, Jens; Treu, Gabriele; Víkingsson, Gisli A.; Wang, Feiyue; Welker, Jeffrey M.; Wilson, Simon J.; Sonne, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-16)
      There has been a considerable number of reports on Hg concentrations in Arctic mammals since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to mercury (Hg) in Arctic biota in 2010 and 2018. Here, we provide an update on the state of the knowledge of health risk associated with Hg concentrations in Arctic marine and terrestrial mammal ...

    • Sea ice reduction drives genetic differentiation among Barents Sea polar bears 

      Maduna, Simo; Aars, Jon; Fløystad, Ida; Klutsch, Cornelya; Fiskebeck, Eve Marie Louise Zeyl; Wiig, Øystein; Ehrich, Dorothee; Andersen, Magnus; Bachmann, Lutz; Derocher, Andrew E.; Nyman, Tommi; Eiken, Hans Geir; Hagen, Snorre (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-08)
      Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (<i>Ursus maritimus</i>) sampled across two decades (1995–2016) from the Svalbard Archipelago, Norway, ...

    • Space-use strategy affects energy requirements in Barents Sea polar bears 

      Blanchet, Marie-Anne; Aars, Jon; Andersen, Magnus; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-02)
      Polar bears Ursus maritimus are currently facing rapid environmental changes with loss of sea ice and shifts in their prey distribution. Two distinct ecotypes exist in the Barents Sea, where sea ice is decreasing at the highest rate in the Arctic. Coastal bears remain within the Archipelago of Svalbard year-round, whereas offshore bears follow the marginal ice zone (MIZ). We explored these 2 ecotypes’ ...

    • Spatial variation in mercury concentrations in polar bear (Ursus maritimus) hair from the Norwegian and Russian Arctic 

      Lippold, Anna; Boltunov, Andrei; Aars, Jon; Andersen, Magnus; Blanchet, Marie-Anne; Dietz, Rune; Eulaers, Igor; Morshina, Tamara N.; Sevastyanov, Vyacheslav S.; Welker, Jeffrey M.; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-02)
      We examined spatial variation in total mercury (THg) concentrations in 100 hair samples collected between 2008 and 2016 from 87 polar bears (Ursus maritimus) from the Norwegian (Svalbard Archipelago, western Barents Sea) and Russian Arctic (Kara Sea, Laptev Sea, and Chukchi Sea). We used latitude and longitude of home range centroid for the Norwegian bears and capture position for the Russian bears ...

    • Temporal trends of persistent organic pollutants in Barents Sea polar bears (Ursus maritimus) in relation to changes in feeding habits and body condition 

      Lippold, Anna; Bourgeon, Sophie; Aars, Jon; Andersen, Magnus; Polder, Anuschka; Lyche, Jan Ludvig; Bytingsvik, Jenny; Jenssen, Bjørn Munro; Derocher, Andrew E.; Welker, Jeffrey Martin; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-14)
      Temporal trends of persistent organic pollutants (POPs: PCBs, OH-PCBs, <i>p,p′</i>-DDE, HCB, β-HCH, oxychlordane, BDE-47, and 153) in relation to changes in feeding habits and body condition in adult female polar bears (<i>Ursus maritimus</i>) from the Barents Sea subpopulation were examined over 20 years (1997–2017). All 306 samples were collected in the spring (April). Both stable isotope values ...

    • Using camera traps to monitor cyclic vole populations 

      Kleiven, Eivind Flittie; Antunes Lopes Da Silva Nicolau, Pedro Guilherme; Sørbye, Sigrunn Holbek; Aars, Jon; Yoccoz, Nigel; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-02)
      Camera traps have become popular labor-efficient and non-invasive tools to study animal populations. The use of camera trap methods has largely focused on large animals and/or animals with identifiable features, with less attention being paid to small mammals, including rodents. Here we investigate the suitability of camera-trap-based abundance indices to monitor population dynamics in two species ...