Contaminant exposure history of yellowknife bay fish : a story of slimy sculpin, burbot, and lake whitefish from otolith microchemistry analysis

Abstract

The thesis examined the otolith microchemistry of slimy sculpin, burbot, and lake whitefish from Yellowknife Bay, Northwest Territories, in relation to the Giant Mine Remediation Project. Trace elements analyzed included arsenic, the mine’s primary contaminant of concern, as well as antimony, copper, lead, strontium, and zinc. Otolith arsenic was lowest, and most variable, in slimy sculpin resident to the exposure area. Significant differences in otolith arsenic, between exposure and reference sites for slimy sculpin and lake whitefish, may be related to arsenic tolerance in exposure area fish whereby lower otolith arsenic content was generally associated with higher tissue arsenic content. In all three species, otolith copper and zinc, and lead in lake whitefish, showed oscillations that likely corresponds to seasonal uptake. Oscillations of otolith strontium were sometimes opposite copper and zinc and may result from seasonal variation in physiological processes. Otolith antimony was generally low in the three species.