Organochlorine pesticide and PCB contents in otter (Lutra lutra) scats from western Scotland

Abstract

Organochlorine pesticide residues and PCBs were measured in 113 otter (Lutra lutra) scat samples from 94 sites in the River Clyde catchment, its estuary and neighboring coastal waters in western Scotland. Contents of pesticide residues were generally low. PCB amounts were high in some regions in the study area (geometric mean contents up to 19.5 mg kg−1 lipid). Potential sources of contamination included industrial areas, a sewage sludge dump and shipping facilities, both naval and commercial. PCBs in tissues were estimated from scats. Analysis of scats provides a useful technique of estimating potential contamination threats to otter populations and can be used to identify biologically significant hot-spots of contamination which may be missed by more familiar surveillance methods.