Levels of toxaphene congeners in white whales ( Delphinapterus leucas) from Svalbard, Norway

Abstract

This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales ( Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636 ± 1992 (SD) ng/g l.w.) and CHB-50 (6579 ± 2214 ng/g l.w.); CHB-62 (232 ± 231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (ΣCHBs = 11,447 ± 4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants ΣDDTs (sum of pp′-DDT, pp′-DDE, pp′-DDD) and ΣPCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of ΣCHBs compared to seals and polar bears ( Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard.