LE3 .A278 2022

2022

Mallory, Mark
O'Driscoll, Nelson

Acadia University

Bachelor of Science

Honours

Biology

Biology

Mercury accumulation in tissues is a significant health risk for many organisms in ecosystems. Most studies have been focused on mercury accumulation in aquatic species leaving a gap in knowledge concerning mercury exposure in terrestrial mammals. Coyotes (Canis latrans) could be a useful biomonitor for terrestrial mammals in Nova Scotia, Canada since they are found across the province and have fairly small home ranges. I analyzed 116 coyote livers for total mercury (THg) concentration, nitrogen and carbon stable isotopes. Additionally, I analyzed a subset of 12 liver samples for methylmercury (MeHg) concentration. A large range of THg concentrations were quantified in coyote liver (8 - 12,043 ng/g), otter liver (434 – 13,144 ng/g), and fisher liver (51 – 23,489 ng/g), all in dry weight. The wide range in coyote liver may be due too opportunistic feeding variations among individuals. In coyote liver, significant correlations between THg, age, and sex were found (p = 0.03), as well as between THg and δ15N (p < 0.001). The mean percentage of total mercury present as methyl mercury (%MeHg) in coyote livers was 43.8% which higher then reported in the literature. Although some age/sex correlations were found when comparing them as dependent variables (e.g., juvenile female coyotes vs. juvenile male coyotes), there were no significant correlations found when treating age and sex as independent variables. The lack of significance in some of the statistical tests may be due to the high variability in THg among individuals. Due to these variations, the data for mean THg in coyote livers are less useful to monitor regional mercury exposure patterns. Maximum THg in coyotes, however, may be useful as an indicator of specific hotspots, however further studies are required with increased sample numbers. Future work should determine the specific mechanisms responsible for the high variation in THg in coyote liver tissue.

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https://scholar.acadiau.ca/islandora/object/theses:3816