ORGANOCHLORINE PESTICIDE-RESIDUES AND PCBS IN DANISH OTTERS (LUTRA-LUTRA)

Tissues (71 liver, 2 muscle) of 73 otters found dead in Denmark betwee n 1980 and 1990 were analyzed for organochlorine pesticide residues an d PCBs. Geometric means of contaminant concentrations were generally l ow, but some otters had PCB concentrations considered to be of concern ; a greater proportion of these came from isolated populations away fr om the main population centre in Limfjord. Animals dying of unknown ca uses had greater concentrations of PCBs than those dying by drowning o r in traffic accidents. Adults had significantly higher concentrations of PCBs. Contaminant concentrations were strongly intercorrelated. Co ncentrations of DDE and PCBs declined significantly during the study p eriod. A sample of otter spraints (faeces) collected in 1990 had low m ean concentrations of contaminants. It is concluded that current conce ntrations of organochlorine pesticide residues and PCBs are unlikely t o pose a threat to otter populations.