Aspects of PCB Levels in Danish Otters (Lutra lutra) and Notes on the Levels in Stone Martens (Martes foina)

The widespread decline of otters in most of lowland Europe has been linked to bioaccumulating toxic chemicals such as PCBs. The Danish population is become restricted to the North West of the country. Liver samples from otters collected between 1991 and 1994 were analysed for PCB content, and this was compared to levels from stone martens, which are found throughout and beyond the otter range. In general, PCB levels were below that thought to cause reproductive and physiological failures, except around Karup. Concentrations in eels was higher than in other fish sampled, especially in Karup, but were not selectively eaten by otters. A larger PCB survey in the otter range and adjacent catchments should be done to find out if PCB concentrations are preventing southward expansion of the otter population.