Steady and non-steady state kinetics describe polychlorinated biphenyl bioaccumulation in natural populations of bluegill (Lepomis macrochirus) and cisco (Coregonus artedi)

Abstract

This study investigated polychlorinated biphenyl (PCB) bioaccumulation patterns across age classes of bluegill ( Lepomis macrochirus ) and cisco ( Coregonus artedi ) collected from Sharbot Lake, Ontario. For bluegill, lipid normalized concentrations of PCB congeners of log Kow < 6.8 did not demonstrate any significant increases across individuals 2–5 years of age. In similarly aged cisco, however, significant age-related increases in lipid normalized PCB concentrations were observed for the majority of these congeners. For PCBs of log Kow > 6.8, these congeners demonstrated significant and similar age-related fugacity increases in both species. These patterns indicated that the bioaccumulation of less hydrophobic PCB congeners in bluegill suggest quicker growth kinetics and demonstrate the potential of this species to achieve steady state within their lifetime. In contrast, PCB bioaccumulation patterns in cisco demonstrated that biomagnification and non-steady state kinetics better reflect the capacity of this species to bioaccumulate PCBs. These results demonstrated that for pollutants of log Kow < 6.8, growth dilution and age-specific metabolic rates are critical for understanding their bioaccumulation by freshwater fish. However, for increasingly hydrophobic pollutants, their bioaccumulation reflects the biology and ecology of these species in their respective warm- and cold-water habitats.