Modeling biomagnification and metabolism of contaminants in harp seals of the Barents Sea

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Fraser, Alison J., Burkow, Ivan C., Wolkers, Hans, Mackay, Don
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: Barents Sea; Boreogadus saida; Phoca groenlandica; polar cod; Themisto libellula
• Online Access: http://dx.doi.org/10.1002/etc.5620210108; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fetc.5620210108; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5620210108

Abstract A simple fugacity‐based bioaccumulation model is presented for harp seals ( Phoca groenlandica ), which feed primarily on polar cod ( Boreogadus saida ) and a pelagic crustacean ( Themisto libellula ). Using concentration data reported for 15 polychlorinated biphenyl (PCB) congeners and 27 pesticides in the food and blubber of harp seals from the Barents Sea, the model was used to determine biomagnification factors and metabolic half‐lives as well as rates of contaminant uptake and loss processes in seals, including a discussion of uncertainty in biomagnification factors and half‐lives. Examination of the model output shows considerable, but highly variable, biomagnification attributable to differences in metabolic rates. It is suggested that two biomagnification factors can be defined and should be used in such assessments, one based on concentration ratios and the other on fugacity ratios or lipid‐normalized concentrations. A maximum biomagnification factor specific to the seal is deduced using biomagnification data for the most persistent substances, and from this, metabolic half‐lives are estimated for all substances. The approach can be applied to other biomagnification situations, thus quantifying metabolic half‐lives as a function of the properties of the bioaccumulating substance and ultimately its molecular structure and the physiological characteristics of the consuming animal.