Polyaromatic hydrocarbons, chlorinated and brominated organic contaminants as tracers of feeding ecology in polar benthic amphipods

Abstract

Concentrations of organochlorines (OCs) such as polychlorinated biphenyls (PCB), dichloro-diphenyl-trichloroethane (DDT), hexachlorocyclobenzene (HCB), chlordanes, and hexa- chlorocyclohexanes (HCHs) were measured in 3 different species of benthic marine amphipods (Eurythenes gryllus, Anonyx nugax, and Paramphitoe hystrix) from 4 different locations: 2 from the Canadian Arctic and 2 from the Norwegian Arctic. In addition, polycyclicaromatic hydrocarbons (PAHs) and brominated flameretardants (BFR) such as polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) were measured in E. gryllus from the Norwegian Arctic. For all species and locations, concentrations of OCs in the amphipods were higher than those found in zoo- plankton and other benthic organisms from the same areas. If the amphipods' OC concentrations were determined by sediment exposure, their values would be close to other benthic infauna, sug- gesting that sediment exposure does not explain the amphipods' higher OC concentrations. In fact, the OC concentrations in benthic amphipods were similar to those in seals and gulls, which provides strong evidence that benthic amphipods are scavengers of higher trophic level carrion. Concentra- tions of PBDE and PAH were also high in E. gryllus (ΣPBDE 115 to 493 ng g -1 lipid weight (lw); ΣPAH 269 ng g -1 lw), and were in the same range as measured in marine animals. BFR concentrations cor- related with PCB and DDT concentrations (PCBs: r 2 = 0.61 p < 0.0076; DDTs: r 2 = 0.530 p < 0.0171), indicating the same bioaccumulation potential. BFRs are thereby emerging problems as their concen- trations increase in Arctic regions.