Objectives 1. To determine tissue residue levels of metals and radionuclides in caribou given its importance as a country food species. 2. To monitor contaminant exposure in caribou as a representative species of the terrestrial arctic ecosystem. 3. To examine metal speciation and isotopes ratios (uranium, thorium, strontium, titanium) which may provide insight into the source of contamination (anthropogenic vs. natural). 4.To provide information on temporal trends in radionuclide and metal levels in several caribou herds to determine whether levels are increasing, decreasing or remaining the same over time. 5. To determine the efficacy of international controls in reducing or eliminating pollutants entering the Canadian Arctic terrestrial ecosystem. Barren-ground caribou are found across northern Canada, and are a major component of the traditional diet in communities across the Northwest Territories (NWT) and Nunavut. Caribou are a good indicator species for terrestrial ecosystem contamination given their wide distribution across northern Canada, the simple air-lichen-caribou food chain, the existing baseline data set, and their importance as a country food species. Three (3) caribou herds from across the NWT and Nunavut have been selected as sentinel herds, with a different herd to be sampled each year to determine tissue residue levels and monitor temporal trends. Field collections will be conducted in cooperation with local Hunter’s and Trapper’s Organizations and/or local aboriginal organizations, utilizing local hunters in planning and conducting the field work. Samples will be tested for a wide range of environmental contaminants including 10 heavy metals and 7 radionuclides.
Wildlife & Fisheries Division GNWT Department of Resources, Wildlife & Economic Development 600, 5102 - 50th Avenue Yellowknife, NWT X1A 3S8 Canada
Metals to be analysed include aluminum (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), total mercury (Hg), nickel (Ni), and zinc (Zn). Analyses will be conducted by atomic absorption spectrophotometry by Envirotest Laboratories in Edmonton, AB. Envirotest is CAEAL accredited. QA/QC of the analysis included blanks, spiked samples, reference materials (DORT) and duplicates. Radionuclide analyses will be conducted by AECL=s Whiteshell Laboratory in Pinawa, MB as per Macdonald et al. (1996). Gamma-emitting radionuclides (Cs-137, K-40, Ra-226, Pb-210, Th-232) will be analysed using a p-type well detector in tissue ashed at approximately 500O C. Po-210 will be analysed by alpha spectrometry using a Po-209 tracer, after plating onto silver discs. Po-210 concentration at the time of sampling will be calculated as the sum of the supported fraction (Pb-210 concentration) and the unsupported fraction, corrected for decay from counting date to plating date. QA/QC procedures include the use of standard radiation sources, duplicates and blanks.
Northwest Territories and Nunavut
Departmental databases. Data available through Canada's Northern Contaminants Program (administered by DIAND)
Braune, B., D. Muir, B. DeMarch, M. Gamberg, K. Poole, R. Currie, M. Dodd, W. Duschenko, J. Eamer, B. Elkin, M. Evans, S. Grundy, C. Hebert, R. Johnstone, K. Kidd, B. Koening, L. Lockhart, H. Marshall, K. Reimer, J. Sanderson and L. Shutt. 19991. Spatial and temporal trends of contaminants in Canadian Arctic freshwater and terrestrial ecosystems: a review. Science of the Total Environment, 230: 145-207. Elkin, B.T. and R.W. Bethke. 1995. Environmental contaminants in caribou in the Northwest Territories, Canada. Science of the Total Environment, 160/161: 307-321. Hebert, C.E., M. Gamberg, B.T. Elkin, M. Simon and R.J. Norstrom. 1996. Polychlorinated dibenzodioxins, dibenzofurans and non-ortho substituted polychlorinated biphenyls in caribou (Rangifer tarandus) from the Canadian Arctic. Science of the Total Environment 185: 195-204. Macdonald, C.R., L.L. Ewing, B.T. Elkin and A.M. Wiewel. 1996. Regional variation in radionuclide concentrations and radiation dose in caribou (Rangifer tarandus) in the Canadian Arctic; 1992-94. Science of the Total Environment 182: 53-73.
Department Specimen Bank. -20 degree celcius chest freezers. Tissues held for up to 5 years. Miscellaneous tissues held
Twenty adult female caribou will be collected from each herd. A variety of biological and morphometric data will be collected including body condition, and a central incisor removed for aging by cementum analysis. Samples from 20 mature, female caribou will be analysed for contaminant levels. Individual liver and kidney samples will be collected for metal analysis. Individual liver, muscle (gastrocnemius) and bone (femur) samples will be analysed for radionuclides. Upon completion of the field collection, the caribou meat from the collection will be provided to the community for local use. Metal analyses will be conducted by atomic absorption spectrophotometry by Envirotest Laboratories in Edmonton, AB. Envirotest is CAEAL accredited. QA/QC of the analysis included blanks, spiked samples, reference materials (DORT) and duplicates. Radionuclide analyses will be conducted by AECL=s Whiteshell Laboratory in Pinawa, MB as per Macdonald et al. (1996). Gamma-emitting radionuclides (Cs-137, K-40, Ra-226, Pb-210, Th-232) will be analysed using a p-type well detector in tissue ashed at approximately 500O C. Po-210 will be analysed by alpha spectrometry using a Po-209 tracer, after plating onto silver discs. Po-210 concentration at the time of sampling will be calculated as the sum of the supported fraction (Pb-210 concentration) and the unsupported fraction, corrected for decay from counting date to plating date. QA/QC procedures include the use of standard radiation sources, duplicates and blanks.
Described above
Canada's Northern Contaminants Program (administered by DIAND)
Local hunters participate in field collections, and provide local knowledge on caribou distribution, movements and sampling.