| Summary: | Dissertation (Ph.D.) University of Alaska Fairbanks, 2017 We evaluated if total mercury (THg) concentrations of keratin-based and bone-based tissues can predict THg concentrations in skeletal muscle, renal medulla, renal cortex, and liver. The THg concentration in matched tissues of 65 red foxes, Vulpes vulpes, from western Alaska was determined. Hair THg concentration had a significant positive correlation with liver, renal medulla, renal cortex, and muscle. The THg concentration is moderately predictive of THg concentration in the renal cortex and liver for these foxes based on R² values (R² = 0.61 and 0.63, respectively), but was not moderately predictive of THg for renal medulla R² = 0.50 and muscle R² = 0.39. Bone is weakly predictive of THg concentration in muscle (R² = 0.40), but not a reliable tissue to predict THg concentration in liver (R² = 0.24), renal cortex (R² = 0.35), or renal medulla (R² = 0.25).These results confirm the potential use of trapped animals, specifically foxes, as useful Arctic sentinel species to inform researchers about patterns in THg levels over time as industrialization of the Arctic continues. Stable isotope analysis was also performed on the same red fox tissues from the first study. We examined stable carbon (δ¹³C) and nitrogen isotopes (δ¹⁵N) to 1) examine the lipid extraction process, 2) evaluate carbon and nitrogen correlations among tissues to establish stable isotope values for modern northern wild fox populations, 3) describe the C:N ratios in males and females, 4) establish trophic positions of freeranging northern red foxes, and 5) to relate the wild red fox trophic level to potential mercury biomagnifications reported in a previous study. Hair, bone, muscle, liver, renal cortex and medulla tissues of the red fox were isotopically significantly different from each other. We found evidence that the Western Alaska red fox was eating a different diet based upon a lower trophic position than red foxes from other northern areas. We concluded that stable isotope data can ...
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