title: Biomagnification of polybrominated diphenyl ether and hexabromocyclododecane flame retardants in the polar bear food chain in Svalbard, Norway.
abstract: Concentrations of brominated flame retardants (BFRs), including polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD), were investigated in an arctic marine food chain consisting of four invertebrate species: polar cod (Boreogadus saida), ringed seals (Pusa hispida), and polar bears (Ursus maritimus). The most abundant BFR, brominated diphenyl ether (BDE)-47, was found in detectable concentrations even in zooplankton, the lowest trophic level examined in this study. Most of the investigated BFRs biomagnified as function of tropic level in the food chain. A noticeable exception occurred at the highest trophic level, the polar bear, in which only BDE-153 was found to increase from its main prey, the ringed seal, indicating that polar bears appear to be able to metabolize and biodegrade most BFRs. In contrast, lower-brominated PBDEs, particularly BDE-47, showed clear signs of bioaccumulation in zooplankton, polar cod, and ringed seals. We suggest that this discrepancy in the fate of BFRs among the different species may be related to greater induction of oxidative detoxification activities in the polar bear. Absorption and debromination rates may be more important for bioaccumulation rates of BFRs in zooplankton, polar cod, and ringed seals. Lipid weight-based concentrations (LWCs) and whole body-based concentrations (WBCs) of BFRs were used to assess biomagnification factors (BMFs). Whole-body concentrations gave the most realistic BMFs, as BMFs derived from LWCs seem to be confounded by the large variability in lipid content of tissues from the investigated species. This study demonstrates that PBDEs and HBCD have reached measurable concentrations even in the lower trophic levels (invertebrates and fish) in the Arctic and biomagnifies in the polar bear food chain.
authors.affiliation: Norwegian University of Science and Technology, Department of Biology, NO 7491 Trondheim, Norway.
authors.forename: Eugen Gravningen
authors.initials: EG
authors.lastname: Sørmo
authors.forename: Maria Pettersvik
authors.initials: MP
authors.lastname: Salmer
authors.forename: Bjørn Munro
authors.initials: BM
authors.lastname: Jenssen
authors.forename: Haakon
authors.initials: H
authors.lastname: Hop
authors.forename: Kine
authors.initials: K
authors.lastname: Baek
authors.forename: Kit Maureen
authors.initials: KM
authors.lastname: Kovacs
authors.forename: Christian
authors.initials: C
authors.lastname: Lydersen
authors.forename: Stig
authors.initials: S
authors.lastname: Falk-Petersen
authors.forename: Geir Wing
authors.initials: GW
authors.lastname: Gabrielsen
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lie
authors.forename: Janneche Utne
authors.initials: JU
authors.lastname: Skaare
mesh_terms: D000818:Animals; D005411:Flame Retardants / Q000032:analysis*; D020387:Food Chain; D048388:Gadiformes / Q000378:metabolism; D006842:Hydrocarbons, Brominated / Q000032:analysis* / Q000378:metabolism; D007448:Invertebrates / Q000737:chemistry; D009664:Norway; D046049:Phoca / Q000378:metabolism; D011075:Polybrominated Biphenyls / Q000032:analysis* / Q000378:metabolism; D001503:Ursidae / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism; D014877:Water Pollution, Chemical
chemical_list: D005411:Flame Retardants; D006842:Hydrocarbons, Brominated; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical; C089796:hexabromocyclododecane