Brominated flame retardants in aquatic organisms from the North Sea in comparison with biota from the high Arctic marine environment

Abstract

AbstractThe extent of trophic transfer of brominated flame retardants (BFRs), including hexabromocyclododecane (HBCD) and seven polybrominated diphenyl ethers (PBDEs), were examined in pelagic and benthic aquatic animals (invertebrates and fish) in a near‐shore estuary environment of the southeastern North Sea (Norway; 59°N). Whole‐body burdens of HBCD and several of the most abundant PBDEs biomagnified with increasing trophic position in the food web. Biomagnification of HBCD was particularly strong, resulting in whole‐body burdens of this compound comparable to those of total PBDEs in the higher‐trophic‐level species. Body burdens of PBDEs were higher in pelagic than in benthic aquatic organisms. This was particularly evident for the lesserbrominated and volatile PBDE congeners. Atmospheric gas–water–phytoplankton exchange of these volatile compounds over the water surface may account for this observation. The PBDE burdens in pelagic zooplankton from the North Sea were more than 60‐fold greater than those in corresponding pelagic zooplankton from the colder high Arctic latitudes (>78°N) of Norway (Svalbard). This great difference may relate to reduced chemical gas–water exchange over open waters at the colder Arctic latitudes. However, previously measured whole‐body burdens of BFRs in other aquatic marine organisms from the high Arctic were comparable or even exceeded those in the North Sea samples of the present study. These include sympagic (sea ice–associated) invertebrates and fish accumulating high burdens of particle‐associated BFRs. The present study provides new insight regarding the distribution of BFRs in ecologically different compartments of marine ecosystems, essential information for understanding the food‐web transfer and geographical dispersal of these compounds.