Assessing the neurotoxicological risk of methylmercury exposure for beluga whales (delphinapterus leucas) harvested in the Mackenzie Delta Estuary.

Arctic marine mammals are exposed to numerous environmental contaminants and some of these compounds are known to damage mammalian nervous systems. Three methods were used to assess neurotoxicological risk of methylmercury (MeHg) exposure for beluga whales (Delphinapterus leucas) in the eastern Beaufort Sea population: characterization of mercury (Hg) accumulation and speciation in brain tissue, neurochemical and molecular biomarkers, and behavioural observations. To conduct this research, I worked closely with the communities of Tuktoyaktuk, NT and Inuvik, NT to conduct three field-sampling seasons on Hendrickson Island, NT, which is a traditional beluga-harvesting site used by Inuvialuit. ...The weight of evidence based on the outcomes from these studies suggests that MeHg exposure may be of toxicological concern for beluga whales from the Eastern Beaufort Sea population. The implications of MeHg-exposure for beluga whales from the eastern Beaufort Sea population at both physiological and population levels are still unclear. --Leaves iii-iv.