A hybrid empirical-mechanistic modeling approach for extrapolating biota-sediment accumulation factors and bioaccumulation factors across species, time, and/or ecosystems.

An approach is presented for extrapolating field-measured biota-sediment accumulation factors (BSAFs) and bioaccumulation factors (BAFs) across species, time, and/or ecosystems. This approach, called the hybrid bioaccumulation modeling approach, uses mechanistic bioaccumulation models to extrapolate field-measured bioaccumulation data (i.e., BSAFs and BAFs) to new sets of ecological conditions. The hybrid approach predicts relative differences in bioaccumulation using food web models with two sets of ecological conditions and parameters: One set for the ecosystem where the BSAFs and/or BAFs were measured, and the other set for the ecological conditions and parameters for which the extrapolated BSAFs and/or BAFs are desired. The field-measured BSAF (or BAF) is extrapolated by adjusting the measured BSAF (or BAF) by the predicted relative difference, which is derived from two separate solutions of the food web model. Extrapolations of polychlorinated biphenyl BSAFs and BAFs for lake trout (Salvelinus namaycush) from southern Lake Michigan to Green Bay of Lake Michigan (Green Bay, WI, USA) walleye (Stizostedion vitreum) and brown trout (Salmo trutta), as well as Hudson River largemouth bass (Micropterus salmoides) and yellow perch (Perca flavescens), resulted in generally better agreement between measured and predicted BSAFs and BAFs with the hybrid approach.