Toxic Chemical Pollution of the St. Lawrence River (Canada) and its Upper Estuary

Abstract

Decline of the Beluga whale population in the upper estuary of the St. Lawrence River may be related to the high content of toxic metals and organic chemicals in their tissues. For three years, the National Water Research Institute has conducted research cruises of the St. Lawrence River to identify the major toxic chemical pollutants in the river and to determine their transport to, and fate in, the upper estuary. The impact of toxic chemicals in the estuarine zone is tied not only to their fate in the increasing salinity and turbidity zone of the upper estuary but to their source, transport mechanisms, and fate in the upstream river.