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Polar Bears and Pollution: Trouble at the top?

Polar Bears and Pollution: Trouble at the top?. Andrew E. Derocher Department of Biological Sciences University of Alberta. Biology 381. Outline. Research activities on polar bears and their ecosystem Background: ecology Geographic variation Hints on possible effects…

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Polar Bears and Pollution: Trouble at the top?

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  1. Polar Bears and Pollution:Trouble at the top? Andrew E. DerocherDepartment of Biological SciencesUniversity of Alberta Biology 381

  2. Outline • Research activities on polar bears and their ecosystem • Background: ecology • Geographic variation • Hints on possible effects… • Trends in persistent organic pollutants • monitoring

  3. Threats to Polar Bears • Climate change • Toxic chemicals • Oil development • Over-harvest

  4. Ocean currents in the Arctic AMAP

  5. Air currents

  6. Distribution of polar bears

  7. Study area

  8. long food chain high fat content Arctic food web

  9. Predation: Trophic relationships FOOD WEB - INTERACTIONS • Social interactions • Parental care AMAP, 1998

  10. MARGINAL ICE ZONE FOOD WEB Scott et al., 1999

  11. Diet composition • Understanding diet is a key component for understanding movement of pollutants through an ecosystem • 2 “new” methods being used • Carbon and nitrogen isotopes • see papers by K.A. Hobson • Fatty acid composition • see Iverson et al. 2004 Ecological Monographs

  12. Telemetry data Satellite collar on adult female

  13. Home ranges of 3 female polar bears Same population but dramatically different strategies

  14. Mean annual location and pollution level • bigger circle indicates higher pollution load (PCB) • larger home range means more energy in which in turn results in higher pollution load Olsen et al. 2003

  15. Effects of Pollution

  16. Polychlorinated biphenyls • 209 congers (congener = type) • Vary by placement and number of chlorine atoms • Vary in toxicity and persistence • Developed in 1929 used in transformers, lubricants, hydraulics

  17. Norstrom et al. 1998, Archives of Environmental Contamination and Toxicology

  18. Polar bear PCB levelsSvalbard-Alaska Andersen et al. 2001, Polar Biology

  19. PCB Chlordane DDT 1,500,000 tonnes of DDT used between 1948-93

  20. Antigen presentation Phagocytosis: Plasma cell with antibody production T-lymphocyte proliferation Virus Bacteria Macrophage T-cell Cytokin production B-cell RIP N K cell Infectedcell Illustration adapted from Ane Reppe

  21. Immune system - PCB relationships

  22. Field experiment • Immunisation trial • Challenge immune system • 2 study areas

  23. Immunisation experiment NORMAL NORMAL? REDUCED? Immune response? Immune response? RECAPTURE RECAPTURE Blood sample Blood sample 5 Week interval CAPTURE - immunise CAPTURE - immunise 35 bears 35 bears HIGH POLLUTION LOW POLLUTION SVALBARD CANADA Lie et al. 2004

  24. Effects of age

  25. PCB in plasma associated with nutritional index 5 4 (77) (3) (131) Ln [PCB 153 (ng/g wet weight)] 3 (27) 2 (3) 1 1 2 3 4 5 Nutritional condition index

  26. Transfer of pollution to young

  27. Concentration of POPs in polar bear milk Lost cubs Kept cubs

  28. OH-PCB Sum PCBs (Hydroxylated PCB) OH-PCB Contaminant metabolites Svalbard vs Canadian High Arctic Sandau et al. in prep. Sum PCBs

  29. Monitoring repeated assessment of status of some quantity to detect change over time

  30. Organochlorine changes between 1967 and 1994 for adult males and females sampled at Svalbard Derocher et al. 2003

  31. Trend of PCB-153 in blood for polar bears in the Norwegian Arctic

  32. Pollution in polar bears may impact: • learning - behaviour • endocrine function • growth patterns • immune system function • survival • litter size • reproductive success

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