Biologic monitoring of environmental contaminants in marine (killer whale) and terrestrial (caribou, moose, and wolf) wildlife populations using scat samples
Lundin, Jessica I.
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Wildlife are intimately associated with contaminated waters and polluted landscapes, serving as sentinels to the health of our shared environment. This project optimized trace analytic techniques for measuring toxicants in scat samples and evaluated contamination levels among Southern Resident killer whales (SRKWs; Orcinus orca) in the Salish Sea and Woodland caribou (Rangifer tarandus caribou), moose (Alces americanus), and Grey wolf (Canis lupus) in the Alberta Oil Sands (AOS). Scat sampling provides an unprecedented opportunity to non-invasively monitor marine and terrestrial wildlife across broad geographic landscapes. Exposure to persistent organic pollutants (POPs) is a primary risk factor for the endangered SRKWs. POPs are lipophilic toxicants associated with adverse health effects including endocrine disruption and reproductive toxicity. Scat samples collected from 2010-2013 demonstrated that contaminant levels are highest, from endogenous lipid stores, and have the greatest potential for toxicity when the whales are nutritionally compromised. Toxicant exposures may contribute to increased mortality and decreased fecundity previously associated with limited prey abundance. Accumulation patterns showed an expected age-related increase, excepting nulliparous females that may have toxicant offloading from unrecorded neonate loss. Mobilization from endogenous lipid stores for milk production and associated transfer of POPs was apparent, particularly for first-born calves with diminished transfer to subsequent calves. POPs were not associated with disruption of thyroid hormone levels as expected. The AOS are third largest international oil reserve; oil production is projected to more than double from 2008-2018. Polycyclic aromatic hydrocarbons (PAHs), well-established carcinogens and mutagens, are a component of crude oil (petrogenic) and form during combustion events (pyrogenic). Scat samples collected in 2009 from areas of the AOS with varying degrees of in situ oil production activity were evaluated for PAH levels. Samples were from Woodland caribou, moose, and Grey wolf, terrestrial species with markedly different dietary preferences and resource utilizations. The high oil production area demonstrated petrogenic (oil) source PAH ratios in moose samples and increased PAHs in wolf samples. Caribou samples from the area of historical forest fire indicated pyrogenic (combustion) source PAHs. The results from these studies should help promote conservation goals to keep our marine and terrestrial environments healthy.
- Biology