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Polar Bears and Pollution: Trouble at the top? Biology 381 Andrew E. Derocher Department of Biological Sciences University of Alberta.

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Presentation on theme: "Polar Bears and Pollution: Trouble at the top? Biology 381 Andrew E. Derocher Department of Biological Sciences University of Alberta."— Presentation transcript:

1 Polar Bears and Pollution: Trouble at the top? Biology 381 Andrew E. Derocher Department of Biological Sciences University of Alberta

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 l Climate change l Toxic chemicals l Oil development l Over-harvest

4 Ocean currents in the Arctic AMAP

5 Air currents

6

7 Distribution of polar bears

8 Study area

9 long food chain high fat content Arctic food web

10 FOOD WEB - INTERACTIONS Predation: –Trophic relationships AMAP, 1998 Social interactions –Parental care

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

12 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

13 Telemetry data Satellite collar on adult female

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

15 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

16 Effects of Pollution

17 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

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

19 Polar bear PCB levels Svalbard- Alaska Andersen et al. 2001, Polar Biology

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

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

22 Immune system - PCB relationships

23 Field experiment Immunisation trial Challenge immune system 2 study areas

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

25 Effects of age

26 PCB in plasma associated with nutritional index Nutritional condition index 12345 1 2 3 4 5 Ln [PCB 153 (ng/g wet weight)] (3) (77) (131) (27) (3)

27 Transfer of pollution to young

28 Concentration of POPs in polar bear milk Lost cubs Kept cubs

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

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

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

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

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


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