Assessing levels of halogenated organic compounds in mass-stranded long-finned pilot whales (Globicephala melas) from Australia

Pollution is a threat to the health of marine mammals worldwide. Mass-strandings are poorly understood, but often involve pilot whales. However, there is limited information regarding pollution in long-finned pilot whales from Australia. Consequently, the profiles and levels of several pollutant classes were investigated in blubber of Tasmanian long-finned pilot whales. DDX levels were highest in all groups, followed by PCBs or MeO-PBDEs and lowest for PBDEs. The concentrations of all pollutants decreased with age in males. This is at least partly due to the growth dilution effect although it might also be caused by decreasing levels of PCBs, PBDEs, DDXs, HCB and CHLs in the environment. Fetus/mother ratios of higher chlorinated PCBs increased with the duration of pregnancy suggesting a preference for offloading via gestation rather than through lactation. Overall, the highest pollutant levels were found in the youngest animals.