Persistent organic contaminants in sediments and biota of Great Slave Lake, Canada: Slave River and long-range atmospheric source influences

摘要

Over 1993-1996, we conducted a series of studies to investigate the distributions of legacy persistent organic pollutants (POPs) in the West Basin and East Arm of Great Slave Lake with a focus on sediments and fish species common in traditional diets; lesser attention was paid to polynuclear aromatic hydrocarbons (PAHs) and chemicals associated with pulp and paper mill activity. The Slave River, formed by the confluence of the Peace and Athabasca Rivers, profoundly affects the limnology of the West Basin by transporting large quantities of water and suspended sediments into the lake. Most POPs occurred in substantially higher concentrations in sediments offshore of the Slave River inflow than in the remote East Arm where long-range atmospheric transport was inferred to be the primary source. POP concentrations tended to be higher in East Arm than the West Basin fish possibly because the low productivity of the East Arm provides less opportunity for contaminant dilution through fish growth and the adsorption onto organic particulates in the water column. Overall, POP concentrations were relatively low in plankton, lake trout fillet and burbot liver from both regions of the lake and generally comparable to other lakes located at similar latitudes. Since 1998, we have been monitoring POPs, mercury and other contaminants in lake trout and burbot under the Northern Contaminants Program in which we are contributing to national and international reporting and to the global understanding of contaminants and climate change on northern and other environments. (C) 2015 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.