Concentrations of organochlorines in sperm whales (Physeter macrocephalus) from Southern Australian waters.

Concentrations of DDTs, PCBs and HCHs were measured in sperm whales involved in two mass stranding events on the west coast of Tasmania, Australia in February 1998. DDTs and PCBs were present in all samples analysed, while only three contained HCHs. The relationships between organochlorines, sex, age and reproductive groups were marked by high variability. Differences in organochlorine concentrations were observed between animals from the two stranding sites and discussed in light of the ecology of this species. Concentrations of all pollutants were stratified throughout the vertical aspect of the blubber and possible reasons for and the implications of this are discussed. Concentrations of compounds were higher than those documented in this species in the Southern Hemisphere previously, although were relatively lower than those documented in the Northern Hemisphere. However, comparisons were confounded by spatial and temporal differences. Continued monitoring of marine mammals throughout this region in a co-coordinated, standardized manner is essential for establishing definite temporal and spatial variations in pollutant concentrations.