[en] 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 habits with bulk stable isotope ratios of carbon and nitrogen. Nitrogen isotopes of amino acids were used to
nvestigate their trophic position. We studied energy expenditure by estimating field metabolic rate using telemetry data. Annual home range size was determined, and spatial gradients in pollutants were explored using latitude and longitude centroid positions of polar bears. Pollutant levels were measured in harp seals from the Greenland Sea and White Sea−Barents Sea as a proxy for a West−East gradient of pollutants in polar bear prey. We showed that pelagic bears had higher pollutant loads than coastal bears because (1) they feed on a higher proportion of marine and higher trophic level prey, (2) they have higher energy requirements and higher prey consumption, (3) they forage in the marginal ice zones, and (4) they feed on prey located closer to pollutant emission sources/transport pathways.
Disciplines :
Aquatic sciences & oceanology
Author, co-author :
Blévin, Pierre
Aars, Jon
Andersen, Magnus
Blanchet, Marie-Anne
Hanssen, Linda
Herzke, Dorte
Jeffreys, Rachel M.
Nordøy, Erling S.
Pinzone, Marianna ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Océanographie biologique
de la Vega, Camille
Routti, Heli
Language :
English
Title :
Pelagic vs Coastal - Key Drivers of Pollutant Levels in Barents Sea Polar Bears with Contrasted Space-Use Strategies
Alternative titles :
[en] Belgium
Publication date :
2020
Journal title :
Environmental Science and Technology
ISSN :
0013-936X
eISSN :
1520-5851
Publisher :
American Chemical Society, Washington, United States - District of Columbia
Wania, F.; Mackay, D. Global Fractionation and Cold Condensation of Low Volatility Organochlorine Compounds in Polar Regions. Ambio 1993, 22, 10-18
Wania, F.; Mackay, D. Peer Reviewed: Tracking the Distribution of Persistent Organic Pollutants. Environ. Sci. Technol. 1996, 30 (9), 390A-396A, 10.1021/es962399q
Ellis, D. A.; Martin, J. W.; De Silva, A. O.; Mabury, S. A.; Hurley, M. D.; Sulbaek Andersen, M. P.; Wallington, T. J. Degradation of Fluorotelomer Alcohols: A Likely Atmospheric Source of Perfluorinated Carboxylic Acids. Environ. Sci. Technol. 2004, 38 (12), 3316-3321, 10.1021/es049860w
Wania, F. A Global Mass Balance Analysis of the Source of Perfluorocarboxylic Acids in the Arctic Ocean. Environ. Sci. Technol. 2007, 41 (13), 4529-4535, 10.1021/es070124c
Taniyasu, S.; Yamashita, N.; Moon, H.-B.; Kwok, K. Y.; Lam, P. K.; Horii, Y.; Petrick, G.; Kannan, K. Does Wet Precipitation Represent Local and Regional Atmospheric Transportation by Perfluorinated Alkyl Substances?. Environ. Int. 2013, 55, 25-32, 10.1016/j.envint.2013.02.005
Sobek, A.; Gustafsson, Ö. Deep Water Masses and Sediments Are Main Compartments for Polychlorinated Biphenyls in the Arctic Ocean. Environ. Sci. Technol. 2014, 48 (12), 6719-6725, 10.1021/es500736q
Hobson, K. A.; Fisk, A.; Karnovsky, N.; Holst, M.; Gagnon, J.-M.; Fortier, M. A Stable Isotope (δ13C, δ15N) Model for the North Water Food Web: Implications for Evaluating Trophodynamics and the Flow of Energy and Contaminants. Deep Sea Res., Part II 2002, 49 (22-23), 5131-5150, 10.1016/S0967-0645(02)00182-0
Sørmo, E. G.; Salmer, M. P.; Jenssen, B. M.; Hop, H.; Bæk, K.; Kovacs, K. M.; Lydersen, C.; Falk-Petersen, S.; Gabrielsen, G. W.; Lie, E. Biomagnification of Polybrominated Diphenyl Ether and Hexabromocyclododecane Flame Retardants in the Polar Bear Food Chain in Svalbard, Norway. Environ. Toxicol. Chem. 2006, 25 (9), 2502-2511, 10.1897/05-591R.1
Kelly, B. C.; Ikonomou, M. G.; Blair, J. D.; Morin, A. E.; Gobas, F. A. Food Web-Specific Biomagnification of Persistent Organic Pollutants. Science 2007, 317 (5835), 236-239, 10.1126/science.1138275
Kelly, B. C.; Ikonomou, M. G.; Blair, J. D.; Surridge, B.; Hoover, D.; Grace, R.; Gobas, F. A. Perfluoroalkyl Contaminants in an Arctic Marine Food Web: Trophic Magnification and Wildlife Exposure. Environ. Sci. Technol. 2009, 43 (11), 4037-4043, 10.1021/es9003894
Letcher, R. J.; Gebbink, W. A.; Sonne, C.; Born, E. W.; McKinney, M. A.; Dietz, R. Bioaccumulation and Biotransformation of Brominated and Chlorinated Contaminants and Their Metabolites in Ringed Seals (Pusa Hispida) and Polar Bears (Ursus Maritimus) from East Greenland. Environ. Int. 2009, 35 (8), 1118-1124, 10.1016/j.envint.2009.07.006
Stroeve, J.; Notz, D. Changing State of Arctic Sea Ice across All Seasons. Environ. Res. Lett. 2018, 13 (10), 103001, 10.1088/1748-9326/aade56
Laidre, K. L.; Stirling, I.; Lowry, L. F.; Wiig, Ø.; Heide-Jørgensen, M. P.; Ferguson, S. H. Quantifying the Sensitivity of Arctic Marine Mammals to Climate-induced Habitat Change. Ecol. Appl. 2008, 18 (sp2), S97-S125, 10.1890/06-0546.1
Stirling, I.; Derocher, A. E. Effects of Climate Warming on Polar Bears: A Review of the Evidence. Glob. Change Biol. 2012, 18 (9), 2694-2706, 10.1111/j.1365-2486.2012.02753.x
Jenssen, B. M.; Villanger, G. D.; Gabrielsen, K. M.; Bytingsvik, J.; Bechshoft, T.; Ciesielski, T. M.; Sonne, C.; Dietz, R. Anthropogenic Flank Attack on Polar Bears: Interacting Consequences of Climate Warming and Pollutant Exposure. Front. Ecol. Evol. 2015, 3, 16, 10.3389/fevo.2015.00016
Andersen, M.; Aars, J. Barents Sea Polar Bears (Ursus Maritimus): Population Biology and Anthropogenic Threats. Polar Res. 2016, 35 (1), 26029, 10.3402/polar.v35.26029
Jenssen, B. M. Endocrine-Disrupting Chemicals and Climate Change: A Worst-Case Combination for Arctic Marine Mammals and Seabirds?. Environ. Health Perspect. 2006, 114, 76-80, 10.1289/ehp.8057
McKinney, M. A.; Letcher, R. J.; Aars, J.; Born, E. W.; Branigan, M.; Dietz, R.; Evans, T. J.; Gabrielsen, G. W.; Peacock, E.; Sonne, C. Flame Retardants and Legacy Contaminants in Polar Bears from Alaska, Canada, East Greenland and Svalbard, 2005-2008. Environ. Int. 2011, 37 (2), 365-374, 10.1016/j.envint.2010.10.008
Routti, H.; Atwood, T. C.; Bechshoft, T.; Boltunov, A.; Ciesielski, T. M.; Desforges, J.-P.; Dietz, R.; Gabrielsen, G. W.; Jenssen, B. M.; Letcher, R. J.; McKinney, M.; Morris, A. D.; Rigét, F. F.; Sonne, C.; Styrishave, B.; Tartu, S. State of Knowledge on Current Exposure, Fate and Potential Health Effects of Contaminants in Polar Bears from the Circumpolar Arctic. Sci. Total Environ. 2019, 664, 1063-1083, 10.1016/j.scitotenv.2019.02.030
Tartu, S.; Bourgeon, S.; Aars, J.; Andersen, M.; Lone, K.; Jenssen, B. M.; Polder, A.; Thiemann, G. W.; Torget, V.; Welker, J. M.; Routti, H. Diet and Metabolic State Are the Main Factors Determining Concentrations of Perfluoroalkyl Substances in Female Polar Bears from Svalbard. Environ. Pollut. 2017, 229, 146-158, 10.1016/j.envpol.2017.04.100
Kissa, E. Fluorinated Surfactants and Repellents, 2 nd ed.; Marcel Dekker: New York, 2001.
Buck, R. C.; Franklin, J.; Berger, U.; Conder, J. M.; Cousins, I. T.; de Voogt, P.; Jensen, A. A.; Kannan, K.; Mabury, S. A.; van Leeuwen, S. P. Perfluoroalkyl and Polyfluoroalkyl Substances in the Environment: Terminology, Classification, and Origins. Integr. Environ. Assess. Manage. 2011, 7 (4), 513-541, 10.1002/ieam.258
Buck, R. C.; Murphy, P. M.; Pabon, M. Chemistry, Properties, and Uses of Commercial Fluorinated Surfactants. In Polyfluorinated Chemicals and Transformation Products. The Handbook of Environmental Chemistry; Knepper, T. P., Lange, F. T., Eds.; Springer Berlin Heidelberg: Berlin, Heidelberg, 2012; pp 1-24.
Tartu, S.; Bourgeon, S.; Aars, J.; Andersen, M.; Polder, A.; Thiemann, G. W.; Welker, J. M.; Routti, H. Sea Ice-Associated Decline in Body Condition Leads to Increased Concentrations of Lipophilic Pollutants in Polar Bears (Ursus Maritimus) from Svalbard, Norway. Sci. Total Environ. 2017, 576, 409-419, 10.1016/j.scitotenv.2016.10.132
Stirling, I.; Derocher, A. E. Possible Impacts of Climatic Warming on Polar Bears. Arctic 1993, 46 (3), 240-245, 10.14430/arctic1348
Amstrup, S. C.; DeMaster, D. P. Polar bear, Ursus maritimus. In Wild mammals of North America: biology, management, and conservation; Feldhamer, G. A., Thompson, B. S. C., Eds.; Johns Hopkins University Press, 2003; Vol. 2, pp 587-610.
Stern, H. L.; Laidre, K. L. Sea-Ice Indicators of Polar Bear Habitat. Cryosphere 2016, 10 (5), 2027-2041, 10.5194/tc-10-2027-2016
Mckinney, M. A.; Pedro, S.; Dietz, R.; Sonne, C.; Fisk, A. T.; Roy, D.; Jenssen, B.ør. M.; Letcher, R. J. A Review of Ecological Impacts of Global Climate Change on Persistent Organic Pollutant and Mercury Pathways and Exposures in Arctic Marine Ecosystems. Curr. Zool. 2015, 61 (4), 617-628, 10.1093/czoolo/61.4.617
Routti, H.; Jenssen, B. M.; Tartu, S. Ecotoxicologic Stress in Arctic Marine Mammals, With Particular Focus on Polar Bears. In Marine Mammal Ecotoxicology; Fossi, M. C., Panti, C., Eds.; Academic Press, 2018; Chapter 13, pp 345-380.
Mauritzen, M.; Derocher, A. E.; Wiig, Ø. Space-Use Strategies of Female Polar Bears in a Dynamic Sea Ice Habitat. Can. J. Zool. 2001, 79 (9), 1704-1713, 10.1139/z01-126
Lone, K.; Aars, J.; Ims, R. A. Site fidelity of Svalbard polar bears revealed by mark-recapture positions. Polar Biol. 2013, 36 (1), 27-39, 10.1007/s00300-012-1235-y
Mauritzen, M.; Belikov, S. E.; Boltunov, A. N.; Derocher, A. E.; Hansen, E.; Ims, R. A.; Wiig, Ø.; Yoccoz, N. Functional Responses in Polar Bear Habitat Selection. Oikos 2003, 100 (1), 112-124, 10.1034/j.1600-0706.2003.12056.x
Thiemann, G. W.; Iverson, S. J.; Stirling, I. Polar Bear Diets and Arctic Marine Food Webs: Insights from Fatty Acid Analysis. Ecol. Monogr. 2008, 78 (4), 591-613, 10.1890/07-1050.1
McKinney, M. A.; Peacock, E.; Letcher, R. J. Sea Ice-Associated Diet Change Increases the Levels of Chlorinated and Brominated Contaminants in Polar Bears. Environ. Sci. Technol. 2009, 43 (12), 4334-4339, 10.1021/es900471g
McKinney, M. A.; Iverson, S. J.; Fisk, A. T.; Sonne, C.; Rigét, F. F.; Letcher, R. J.; Arts, M. T.; Born, E. W.; Rosing-Asvid, A.; Dietz, R. Global Change Effects on the Long-Term Feeding Ecology and Contaminant Exposures of East Greenland Polar Bears. Glob. Change Biol. 2013, 19 (8), 2360-2372, 10.1111/gcb.12241
Lone, K.; Merkel, B.; Lydersen, C.; Kovacs, K. M.; Aars, J. Sea Ice Resource Selection Models for Polar Bears in the Barents Sea Subpopulation. Ecography 2018, 41 (4), 567-578, 10.1111/ecog.03020
Løno, O. The Polar Bear (Ursus Maritimus) in the Svalbard Area; Norsk Polarinstitutt Skrifter; Universitetsforlaget: Oslo, 1970; Vol. 149.
Derocher, A. E.; Wiig, Ø.; Andersen, M. Diet Composition of Polar Bears in Svalbard and the Western Barents Sea. Polar Biol. 2002, 25 (6), 448-452, 10.1007/s00300-002-0364-0
Iversen, M.; Aars, J.; Haug, T.; Alsos, I. G.; Lydersen, C.; Bachmann, L.; Kovacs, K. M. The Diet of Polar Bears (Ursus Maritimus) from Svalbard, Norway, Inferred from Scat Analysis. Polar Biol. 2013, 36 (4), 561-571, 10.1007/s00300-012-1284-2
Prop, J.; Aars, J.; Bårdsen, B.-J.; Hanssen, S. A.; Bech, C.; Bourgeon, S.; de Fouw, J.; Gabrielsen, G. W.; Lang, J.; Noreen, E.; Oudman, T.; Sittler, B.; Stempniewicz, L.; Tombre, I.; Wolters, E.; Moe, B. Climate Change and the Increasing Impact of Polar Bears on Bird Populations. Front. Ecol. Evol. 2015, 3, 33, 10.3389/fevo.2015.00033
Tartu, S.; Bourgeon, S.; Aars, J.; Andersen, M.; Ehrich, D.; Thiemann, G. W.; Welker, J. M.; Routti, H. Geographical Area and Life History Traits Influence Diet in an Arctic Marine Predator. PLoS One 2016, 11 (5), e0155980, 10.1371/journal.pone.0155980
Olsen, G. H.; Mauritzen, M.; Derocher, A. E.; Sørmo, E. G.; Skaare, J. U.; Wiig, Ø.; Jenssen, B. M. Space-Use Strategy Is an Important Determinant of PCB Concentrations in Female Polar Bears in the Barents Sea. Environ. Sci. Technol. 2003, 37 (21), 4919-4924, 10.1021/es034380a
van Beest, F. M.; Aars, J.; Routti, H.; Lie, E.; Andersen, M.; Pavlova, V.; Sonne, C.; Nabe-Nielsen, J.; Dietz, R. Spatiotemporal Variation in Home Range Size of Female Polar Bears and Correlations with Individual Contaminant Load. Polar Biol. 2016, 39 (8), 1479-1489, 10.1007/s00300-015-1876-8
Tartu, S.; Aars, J.; Andersen, M.; Polder, A.; Bourgeon, S.; Merkel, B.; Lowther, A. D.; Bytingsvik, J.; Welker, J. M.; Derocher, A. E.; Jenssen, B. M.; Routti, H. Choose Your Poison-Space-Use Strategy Influences Pollutant Exposure in Barents Sea Polar Bears. Environ. Sci. Technol. 2018, 52 (5), 3211-3221, 10.1021/acs.est.7b06137
Andersen, M.; Lie, E.; Derocher, A. E.; Belikov, S. E.; Bernhoft, A.; Boltunov, A. N.; Garner, G. W.; Skaare, J. U.; Wiig, Ø. Geographic Variation of PCB Congeners in Polar Bears (Ursus Maritimus) from Svalbard East to the Chukchi Sea. Polar Biol. 2001, 24 (4), 231-238, 10.1007/s003000000201
Lie, E.; Bernhoft, A.; Riget, F.; Belikov, S. E.; Boltunov, A. N.; Derocher, A. E.; Garner, G. W.; Wiig, Ø.; Skaare, J. U. Geographical Distribution of Organochlorine Pesticides (OCPs) in Polar Bears (Ursus Maritimus) in the Norwegian and Russian Arctic. Sci. Total Environ. 2003, 306 (1), 159-170, 10.1016/S0048-9697(02)00490-4
McClelland, J. W.; Montoya, J. P. Trophic Relationships and the Nitrogen Isotopic Composition of Amino Acids in Plankton. Ecology 2002, 83 (8), 2173-2180, 10.1890/0012-9658(2002)083[2173:TRATNI]2.0.CO;2
Chikaraishi, Y.; Ogawa, N. O.; Kashiyama, Y.; Takano, Y.; Suga, H.; Tomitani, A.; Miyashita, H.; Kitazato, H.; Ohkouchi, N. Determination of Aquatic Food-Web Structure Based on Compound-Specific Nitrogen Isotopic Composition of Amino Acids. Limnol. Oceanogr.: Methods 2009, 7 (11), 740-750, 10.4319/lom.2009.7.740
Mauritzen, M.; Derocher, A. E.; Wiig, Ø.; Belikov, S. E.; Boltunov, A. N.; Hansen, E.; Garner, G. W. Using Satellite Telemetry to Define Spatial Population Structure in Polar Bears in the Norwegian and Western Russian Arctic. J. Appl. Ecol. 2002, 39 (1), 79-90, 10.1046/j.1365-2664.2002.00690.x
Stirling, I.; Spencer, C.; Andriashek, D. Immobilization of Polar Bears (Ursus Maritimus) with Telazol® in the Canadian Arctic. J. Wildl. Dis. 1989, 25 (2), 159-168, 10.7589/0090-3558-25.2.159
Derocher, A. E.; Wiig, Ø. Postnatal Growth in Body Length and Mass of Polar Bears (Ursus Maritimus) at Svalbard. J. Zool. 2002, 256 (3), 343-349, 10.1017/S0952836902000377
Durner, G. M.; Douglas, D. C.; Albeke, S. E.; Whiteman, J. P.; Amstrup, S. C.; Richardson, E.; Wilson, R. R.; Ben-David, M. Increased Arctic Sea Ice Drift Alters Adult Female Polar Bear Movements and Energetics. Glob. Change Biol. 2017, 23 (9), 3460-3473, 10.1111/gcb.13746
Pagano, A. M.; Durner, G. M.; Rode, K. D.; Atwood, T. C.; Atkinson, S. N.; Peacock, E.; Costa, D. P.; Owen, M. A.; Williams, T. M. High-Energy, High-Fat Lifestyle Challenges an Arctic Apex Predator, the Polar Bear. Science 2018, 359 (6375), 568-572, 10.1126/science.aan8677
Scotter, S. E.; Tryland, M.; Nymo, I. H.; Hanssen, L.; Harju, M.; Lydersen, C.; Kovacs, K. M.; Klein, J.; Fisk, A. T.; Routti, H. Contaminants in Atlantic Walruses in Svalbard Part 1: Relationships between Exposure, Diet and Pathogen Prevalence. Environ. Pollut. 2019, 244, 9-18, 10.1016/j.envpol.2018.10.001
Hanssen, L.; Dudarev, A. A.; Huber, S.; Odland, J. Ø.; Nieboer, E.; Sandanger, T. M. Partition of Perfluoroalkyl Substances (PFASs) in Whole Blood and Plasma, Assessed in Maternal and Umbilical Cord Samples from Inhabitants of Arctic Russia and Uzbekistan. Sci. Total Environ. 2013, 447, 430-437, 10.1016/j.scitotenv.2013.01.029
Newsome, S. D.; Clementz, M. T.; Koch, P. L. Using Stable Isotope Biogeochemistry to Study Marine Mammal Ecology. Mar. Mammal Sci. 2010, 26 (3), 509-572, 10.1111/j.1748-7692.2009.00354.x
Newsome, S. D.; Martinez del Rio, C.; Bearhop, S.; Phillips, D. L. A Niche for Isotopic Ecology. Front. Ecol. Environ. 2007, 5 (8), 429-436, 10.1890/060150.1
Hobson, K. A.; Welch, H. E. Determination of Trophic Relationships within a High Arctic Marine Food Web Using δ13C and δ15N Analysis. Mar. Ecol.: Prog. Ser. 1992, 84 (1), 9-18, 10.3354/meps084009
Kelly, J. F. Stable Isotopes of Carbon and Nitrogen in the Study of Avian and Mammalian Trophic Ecology. Can. J. Zool. 2000, 78 (1), 1-27, 10.1139/z99-165
Hobson, K. A.; Piatt, J. F.; Pitocchelli, J. Using Stable Isotopes to Determine Seabird Trophic Relationships. J. Anim. Ecol. 1994, 63 (4), 786-798, 10.2307/5256
Hobson, K. A. Tracing Origins and Migration of Wildlife Using Stable Isotopes: A Review. Oecologia 1999, 120 (3), 314-326, 10.1007/s004420050865
Minagawa, M.; Wada, E. Stepwise Enrichment of 15N along Food Chains: Further Evidence and the Relation between δ15N and Animal Age. Geochim. Cosmochim. Acta 1984, 48 (5), 1135-1140, 10.1016/0016-7037(84)90204-7
Popp, B. N.; Graham, B. S.; Olson, R. J.; Hannides, C. C. S.; Lott, M. J.; López-Ibarra, G. A.; Galván-Magaña, F.; Fry, B. Insight into the Trophic Ecology of Yellowfin Tuna, Thunnus Albacares, from Compound-Specific Nitrogen Isotope Analysis of Proteinaceous Amino Acids. Terrestrial Ecology; Stable Isotopes as Indicators of Ecological Change; Elsevier, 2007; Vol. 1, pp 173-190.
Chikaraishi, Y.; Ogawa, N. O.; Ohkouchi, N. Further evaluation of the trophic level estimation based on nitrogen isotopic composition of amino acids. In Earth, life, and isotopes; Ohkouchi, N., Tayasu, I., Koba, K., Eds.; Kyoto University Press, 2010; pp 37-51.
Nielsen, J. M.; Popp, B. N.; Winder, M. Meta-Analysis of Amino Acid Stable Nitrogen Isotope Ratios for Estimating Trophic Position in Marine Organisms. Oecologia 2015, 178 (3), 631-642, 10.1007/s00442-015-3305-7
Germain, L. R.; Koch, P. L.; Harvey, J.; McCarthy, M. D. Nitrogen Isotope Fractionation in Amino Acids from Harbor Seals: Implications for Compound-Specific Trophic Position Calculations. Mar. Ecol.: Prog. Ser. 2013, 482, 265-277, 10.3354/meps10257
Rode, K. D.; Stricker, C. A.; Erlenbach, J.; Robbins, C. T.; Cherry, S. G.; Newsome, S. D.; Cutting, A.; Jensen, S.; Stenhouse, G.; Brooks, M.; Hash, A.; Nicassio, N. Isotopic Incorporation and the Effects of Fasting and Dietary Lipid Content on Isotopic Discrimination in Large Carnivorous Mammals. Physiol. Biochem. Zool. 2016, 89 (3), 182-197, 10.1086/686490
Rogers, M. C.; Peacock, E.; Simac, K.; O'Dell, M. B.; Welker, J. M. Diet of Female Polar Bears in the Southern Beaufort Sea of Alaska: Evidence for an Emerging Alternative Foraging Strategy in Response to Environmental Change. Polar Biol. 2015, 38 (7), 1035-1047, 10.1007/s00300-015-1665-4
Pinheiro, J.; Bates, D.; DebRoy, S.; Sarkar, D. nlme: Linear and Nonlinear Mixed Effects Models. R package, version 3.1-140, 2019; https://CRAN.R-project.org/package=nlme.
Routti, H.; Aars, J.; Fuglei, E.; Hanssen, L.; Lone, K.; Polder, A.; Pedersen, Å. Ø.; Tartu, S.; Welker, J. M.; Yoccoz, N. G. Emission Changes Dwarf the Influence of Feeding Habits on Temporal Trends of Per-and Polyfluoroalkyl Substances in Two Arctic Top Predators. Environ. Sci. Technol. 2017, 51 (20), 11996-12006, 10.1021/acs.est.7b03585
Lippold, A.; Bourgeon, S.; Aars, J.; Andersen, M.; Polder, A.; Lyche, J. L.; Bytingsvik, J.; Jenssen, B. M.; Derocher, A. E.; Welker, J. M.; Routti, H. Temporal Trends of Persistent Organic Pollutants in Barents Sea Polar Bears (Ursus Maritimus) in Relation to Changes in Feeding Habits and Body Condition. Environ. Sci. Technol. 2019, 53 (2), 984-995, 10.1021/acs.est.8b05416
Zuur, A.; Ieno, E. N.; Walker, N.; Saveliev, A. A.; Smith, G. M. Mixed Effects Models and Extensions in Ecology with R; Statistics for Biology and Health; Springer-Verlag: New York, 2009.
Jackson, A. L.; Inger, R.; Parnell, A. C.; Bearhop, S. Comparing Isotopic Niche Widths among and within Communities: SIBER-Stable Isotope Bayesian Ellipses in R. J. Anim. Ecol. 2011, 80 (3), 595-602, 10.1111/j.1365-2656.2011.01806.x
Gelman, A.; Hill, J. Data Analysis Using Regression and Multilevel/Hierarchical Models; Cambridge University Press, 2006.
Freckleton, R. P. Dealing with Collinearity in Behavioural and Ecological Data: Model Averaging and the Problems of Measurement Error. Behav. Ecol. Sociobiol. 2011, 65 (1), 91-101, 10.1007/s00265-010-1045-6
Burnham, K. P.; Anderson, D. R. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach, 2 nd ed.; Springer-Verlag: New York, 2002.
Johnson, J. B.; Omland, K. S. Model Selection in Ecology and Evolution. Trends Ecol. Evol. 2004, 19 (2), 101-108, 10.1016/j.tree.2003.10.013
Grueber, C. E.; Nakagawa, S.; Laws, R. J.; Jamieson, I. G. Multimodel Inference in Ecology and Evolution: Challenges and Solutions. J. Evol. Biol. 2011, 24 (4), 699-711, 10.1111/j.1420-9101.2010.02210.x
Lukacs, P. M.; Burnham, K. P.; Anderson, D. R. Model Selection Bias and Freedman's Paradox. Ann. Inst. Stat. Math. 2010, 62 (1), 117-125, 10.1007/s10463-009-0234-4
du Prel, J.-B.; Hommel, G.; Röhrig, B.; Blettner, M. Confidence Interval or P-Value?. Dtsch. Ärztebl. Int. 2009, 106 (19), 335-339, 10.3238/arztebl.2009.0335
McMahon, K. W.; McCarthy, M. D. Embracing Variability in Amino Acid δ15N Fractionation: Mechanisms, Implications, and Applications for Trophic Ecology. Ecosphere 2016, 7 (12), e01511, 10.1002/ecs2.1511
Lorrain, A.; Graham, B.; Ménard, F.; Popp, B.; Bouillon, S.; Van Breugel, P.; Cherel, Y. Nitrogen and Carbon Isotope Values of Individual Amino Acids: A Tool to Study Foraging Ecology of Penguins in the Southern Ocean. Mar. Ecol.: Prog. Ser. 2009, 391, 293-306, 10.3354/meps08215
Dale, J. J.; Wallsgrove, N. J.; Popp, B. N.; Holland, K. N. Nursery Habitat Use and Foraging Ecology of the Brown Stingray Dasyatis Lata Determined from Stomach Contents, Bulk and Amino Acid Stable Isotopes. Mar. Ecol.: Prog. Ser. 2011, 433, 221-236, 10.3354/meps09171
Choy, C. A.; Davison, P. C.; Drazen, J. C.; Flynn, A.; Gier, E. J.; Hoffman, J. C.; McClain-Counts, J. P.; Miller, T. W.; Popp, B. N.; Ross, S. W.; Sutton, T. T. Global Trophic Position Comparison of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses. PLoS One 2012, 7 (11), e50133, 10.1371/journal.pone.0050133
Hoen, D. K.; Kim, S. L.; Hussey, N. E.; Wallsgrove, N. J.; Drazen, J. C.; Popp, B. N. Amino Acid 15N Trophic Enrichment Factors of Four Large Carnivorous Fishes. J. Exp. Mar. Biol. Ecol. 2014, 453, 76-83, 10.1016/j.jembe.2014.01.006
Bradley, C. J.; Wallsgrove, N. J.; Choy, C. A.; Drazen, J. C.; Hetherington, E. D.; Hoen, D. K.; Popp, B. N. Trophic Position Estimates of Marine Teleosts Using Amino Acid Compound Specific Isotopic Analysis. Limnol. Oceanogr.: Methods 2015, 13 (9), 476-493, 10.1002/lom3.10041
Derocher, A. E.; Wiig, Ø.; Bangjord, G. Predation of Svalbard Reindeer by Polar Bears. Polar Biol. 2000, 23 (10), 675-678, 10.1007/s003000000138
Stempniewicz, L.; Kidawa, D.; Barcikowski, M.; Iliszko, L. Unusual Hunting and Feeding Behaviour of Polar Bears on Spitsbergen. Polar Rec. 2014, 50 (2), 216-219, 10.1017/S0032247413000053
Macdonald, R. W.; Harner, T.; Fyfe, J. Recent Climate Change in the Arctic and Its Impact on Contaminant Pathways and Interpretation of Temporal Trend Data. Sci. Total Environ. 2005, 342 (1), 5-86, 10.1016/j.scitotenv.2004.12.059
Kallenborn, R.; MacDonald, R. Contaminant pathways and change in the cryosphere. Snow, Water, Ice and Permafrost in the Arctic (SWIPA): Climate Change and the Cryosphere; Arctic Monitoring and Assessment Programme (AMAP): Oslo, Norway, 2011.
Ramsay, M. A.; Stirling, I. Reproductive Biology and Ecology of Female Polar Bears (Ursus Maritimus). J. Zool. 1988, 214 (4), 601-633, 10.1111/j.1469-7998.1988.tb03762.x
Divine, D. V.; Dick, C. Historical Variability of Sea Ice Edge Position in the Nordic Seas. J. Geophys. Res. 2006, 111 (C1). 10.1029/2004JC002851.
Walter, N.; Gerland, S.; Granskog, M. A.; Jeffrey, R. K.; Haas, C.; Hovelsrud, G. R.; Kovacs, K. M.; Makshtas, A.; Michel, C.; Perovich, D.; Reist, J. D.; van Oort, B. O. H. Sea Ice. In Snow, Water, Ice and Permafrost in the Arctic (SWIPA): Climate Change and the Cryosphere; Arctic Monitoring and Assessment Programme (AMAP): Oslo, Norway, 2011; pp 538.
AMAP. Snow, Water, Ice and Permafrost in the Arctic (SWIPA) 2017. Arctic Monitoring and Assessment Programme (AMAP): Oslo, Norway, 2017.
Wang, Z.; Cousins, I. T.; Scheringer, M.; Buck, R. C.; Hungerbühler, K. Global Emission Inventories for C4-C14 Perfluoroalkyl Carboxylic Acid (PFCA) Homologues from 1951 to 2030, Part I: Production and Emissions from Quantifiable Sources. Environ. Int. 2014, 70, 62-75, 10.1016/j.envint.2014.04.013
Wang, Z.; Boucher, J. M.; Scheringer, M.; Cousins, I. T.; Hungerbühler, K. Toward a Comprehensive Global Emission Inventory of C4-C10 Perfluoroalkanesulfonic Acids (PFSAs) and Related Precursors: Focus on the Life Cycle of C8-Based Products and Ongoing Industrial Transition. Environ. Sci. Technol. 2017, 51 (8), 4482-4493, 10.1021/acs.est.6b06191
Shindell, D. T.; Chin, M.; Dentener, F.; Doherty, R. M.; Faluvegi, G.; Fiore, A. M.; Hess, P.; Koch, D. M.; MacKenzie, I. A.; Sanderson, M. G.; Schultz, M. G.; Schulz, M.; Stevenson, D. S.; Teich, H.; Textor, C.; Wild, O.; Bergmann, D. J.; Bey, I.; Bian, H.; Cuvelier, C.; Duncan, B. N.; Folberth, G.; Horowitz, L. W.; Jonson, J.; Kaminski, J. W.; Marmer, E.; Park, R.; Pringle, K. J.; Schroeder, S.; Szopa, S.; Takemura, T.; Zeng, G.; Keating, T. J.; Zuber, A. Multi-Model Assessment of Pollution Transport to the Arctic. Atmos. Chem. Phys. 2008, 8 (17), 5353-5372, 10.5194/acp-8-5353-2008
Kwok, K. Y.; Yamazaki, E.; Yamashita, N.; Taniyasu, S.; Murphy, M. B.; Horii, Y.; Petrick, G.; Kallerborn, R.; Kannan, K.; Murano, K.; Lam, P. K. S. Transport of Perfluoroalkyl Substances (PFAS) from an Arctic Glacier to Downstream Locations: Implications for Sources. Sci. Total Environ. 2013, 447, 46-55, 10.1016/j.scitotenv.2012.10.091
Codling, G.; Halsall, C.; Ahrens, L.; Del Vento, S.; Wiberg, K.; Bergknut, M.; Laudon, H.; Ebinghaus, R. The Fate of Per-and Polyfluoroalkyl Substances within a Melting Snowpack of a Boreal Forest. Environ. Pollut. 2014, 191, 190-198, 10.1016/j.envpol.2014.04.032
Durner, G. M.; Douglas, D. C.; Nielson, R. M.; Amstrup, S. C.; McDonald, T. L.; Stirling, I.; Mauritzen, M.; Born, E. W.; Wiig, Øy.; DeWeaver, E.; Serreze, M. C.; Belikov, S. E.; Holland, M. M.; Maslanik, J.; Aars, J.; Bailey, D. A.; Derocher, A. E. Predicting 21st-Century Polar Bear Habitat Distribution from Global Climate Models. Ecol. Monogr. 2009, 79 (1), 25-58, 10.1890/07-2089.1