Pelagic vs CoastalKey Drivers of Pollutant Levels in Barents Sea Polar Bears with Contrasted Space-Use Strategies

• Published in: Environmental science & technology Vol. 54; no. 2; pp. 985 - 995
• Main Authors: Blévin, Pierre, Aars, Jon, Andersen, Magnus, Blanchet, Marie-Anne, Hanssen, Linda, Herzke, Dorte, Jeffreys, Rachel M, Nordøy, Erling S, Pinzone, Marianna, de la Vega, Camille, Routti, Heli
• Format: Journal Article Web Resource
• Language: English
• Published: United States American Chemical Society 21.01.2020
• Subjects: Air pollution; Amino acids; Animals; Aquatic mammals; Aquatic sciences & oceanology; Arctic Regions; Centroids; ecology; Energy expenditure; Energy requirements; Environmental Pollutants; Ethers; Female; Greenland; Home range; Isotope ratios; Isotopes; Levels; Life sciences; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Metabolic rate; Nitrogen; Nitrogen isotopes; Organic compounds; Organochlorine pesticides; PCB; PCB compounds; Perfluoroalkyl & polyfluoroalkyl substances; Pesticides; Polar Bear; Polar bears; Pollutant; Pollutants; Pollution dispersion; Pollution load; Pollution sources; Polybrominated diphenyl ethers; Polychlorinated Biphenyls; Prey; Sciences aquatiques & océanologie; Sciences du vivant; Seals; Seals, Earless; Stable isotopes; Telemetry; Trophic levels; Ursidae; VDP; Arctic Regions; Greenland; Barents Sea
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/acs.est.9b04626

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 investigate 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.