A combined food web toxicokinetic and species bioenergetic model for predicting seasonal PCB elimination by yellow perch (Perca flavescens).
A commonly used toxicokinetic model was coupled to a bioenergetic submodel optimized for yellow perch and an empirical growth submodel to predict daily PCB elimination flux in three size classes of fish under seasonally variable temperatures. Across seasons, the bioenergetic model predicted highly variable gill ventilation and fecal egestion rates which varied by 74.2-111.2 fold and 35-65 fold, respectively, over the annual cycle. The empirical growth model accounted for seasonal trends in overwintering lipid losses evident for all fish size classes and growth, evident only for the small fish size class, during warm water periods. The toxicokinetic model described seasonal trends in congener specific PCB mass balance of fish, but tended to overestimate PCB elimination for less hydrophobic congeners when the recommended gill transfer efficiency term (Ew) of 0.54 was used. Downward adjustment of Ew to an average value of 0.14 produced the strongest model fit for several low Kow PCBs but had less effect on model performance for mid- to high Kow congeners. The toxicokinetic model was less sensitive to parameters involved in fecal elimination of PCBs when applied to low and mid-Kow PCBs. This study demonstrates the importance of seasonal trends in metabolic rate, growth, and overwintering weight loss as factors that modify PCB toxicokinetics in temperate fish.
Drouillard
Ken G
KG
Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada. kgd@uwindsor.ca
Paterson
Gordon
G
Haffner
G Douglas
GD
D000818:Animals; D020387:Food Chain; D008962:Models, Theoretical; D010471:Perches / Q000254:growth & development / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics* / Q000633:toxicity*; D012621:Seasons; D013696:Temperature
D011078:Polychlorinated Biphenyls