Trophic transfer of flame retardants (PBDEs) in the food web of Lake Erie

We studied the occurrence, bioaccumulation, and biomagnification of polybrominated diphenyl ethers (PBDEs) in a mixed food web of native and non-native species in Lake Erie. Non-native species were found at the basal level of the web (dreissenid mussels), at the intermediate level (round gobies, rainbow smelt), and at the top predator rung (steelhead trout). Mean concentrations of total PBDEs in biota (wet mass) ranged from 1.03 ng.g(-1) in dreissenid mussels to 31.5 ng.g(-1) in walleye. Large piscivores (smallmouth bass, steelhead trout, walleye, and lake trout) had PBDE concentrations three to seven times higher than prey fish (emerald shiners, round gobies, rainbow smelt, and yellow perch). Walleye had the highest concentration of PBDEs among all of the fish species analyzed. BDE 47 was the dominant congener found in biota. Biomagnification factors (corrected for trophic level) indicated that total PBDEs were biomagnified in three fish species: rainbow smelt, smallmouth bass, and steelhead trout. Overall, BDEs 47 and 100 had the highest level of trophic magnification (TMF) from invertebrates to top predators. For fish species, the highest TMF was for BDEs 47 and 49+71. We found that dreissenid mussels and round gobies had the lowest PBDE contamination of the organisms analyzed; however, other non-native prey species such as rainbow smelt contributed significantly to the biomagnification of PBDEs.