The determination of concentrations and enantiomeric fractions of both chiral and achiral OCPs in the Lac La Biche aquatic food web were carried to elucidate sources, bioaccumulation, and tropodynamics of target compounds. Organochlorine pesticides were detected in the Lac La Biche food web and biomagnification is occurring. γ-HCH is a major pollutant in the fishes of Lac La Biche. Adult cormorants appear to have sufficient biological capacity to eliminate γ-HCH and appear to contain completely different organochlorine pollutants compared to other organisms of the food web. Cormorants exhibit particularly high EFs for oxychlordane and heptachlor- exo -epoxide. Double-crested cormorants appear to be a means of removal for local-source pollutants from Lac La Biche; however, more recalcitrant pollutants from other locales are brought to Lac La Biche by these same birds. Northern pike appear to enantioselectively compartmentalize α-HCH in different tissues.