High liver content of polybrominated diphenyl ether (PBDE) in otters (Lutra lutra) from England and Wales

Polybrominated diphenyl ethers (PBDEs), used as flame retardants since the 1970s, are being phased out of use, but are persistent and widespread in the environment. Historical declines in Eurasian otter (Lutra lutra) populations have been associated with exposure to dieldrin and polychlorinated biphenyls (PCBs), but links with other persistent organic pollutants have not been explored. In this study, liver samples from 129 otters, collected across England and Wales from 1995-2006, were analysed for PBDEs, together with PCBs, DDT breakdown products, and hexachlorobenzene. Associations with geographical location and life history parameters were explored. Concentrations of PBDEs in otters (∑BDE 12-70000ngg(-1) lipid) paralleled those measured in marine mammals, with PBDE-47 the dominant congener and high levels of PBDE-99 and -100. Otter livers contained high concentrations of PBDE-153 and -209, typical of terrestrial top predators. Inter-individual variation in PBDE concentrations was high and correlated with geographical location. ∑PBDE was 25% of ∑PCB, and comparable with ∑DDT, identifying PBDEs as a major contaminant in otter populations in England and Wales.