Use of stable isotopes of N and C to explain unexpectedly high levels of PCBs and other organochlorines in walrus
- Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada)
- Canadian Wildlife Service, Saskatoon, Saskatchewan (Canada)
Walrus (Odobenus rosmarus) blubber from Inukjuak and Akulivik (E. Hudson Bay), Foxe Basin and E. Baffin Is. was analyzed for PCB congeners and other persistent organochlorines (DDT, toxaphene, chlordanes) as part of studies documenting spatial trends in contaminants in Canadian arctic marine biota. Samples from 18 of 53 individuals had wet weight concentrations of {Sigma}PCBs ranging from 1 to 20 {mu}g//g; the remaining individuals had much lower concentrations. Highest concentrations were found in samples from Inukjuak where 11 of 13 animals (males and females) had high levels. {Sigma}PCB concentrations greater than 0.5 {mu}g/g were unexpected based on previous studies in Greenland and Alaska. Local contamination was ruled out because DDT, chlordanes and toxaphene were all elevated, and high levels were found in both males and females from 2 of 4 other locations. {sup 13}C and {sup 15}N isotope measurements using muscle samples from the jaws of walrus and seals, showed that walrus with high EPCB had higher {delta}{sup 15}N values than those with low PCBs. The results suggest that the walrus with elevated organochlorines are feeding at a higher trophic level than those with low levels and are probably utilizing ringed seals (Phoca hispida) for a significant proportion of their diet.
- OSTI ID:
- 49523
- Report Number(s):
- CONF-9410273-; TRN: IM9523%%346
- Resource Relation:
- Conference: 15. annual meeting of the Society of Environmental Toxicology and Chemistry (SETAC), Denver, CO (United States), 30 Oct - 3 Nov 1994; Other Information: PBD: 1994; Related Information: Is Part Of Society of Environmental Toxicology and Chemistry 15th annual meeting: Abstract book. Ecological risk: Science, policy, law, and perception; PB: 286 p.
- Country of Publication:
- United States
- Language:
- English
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