A note on mercury and organochlorine accumulation in the Antarctic fin whale based on JARPAII data

Total mercury (Hg) was determined in 10 liver and 16 muscle samples from fin whales sampled by JARPAII in the period from 2005/2006 to 2010/2011. In addition PCBs, DDTs, HCHs, HCB and CHLs were determined in two blubber samples from fin whales sampled in 2010/2011. Mean concentrations of total Hg in liver and muscle samples were 0.052 and 0.021 (ppm wet wt.), respectively. Mean concentrations of PCBs, DDTs, HCHs, HCB and CHLs were 6.5, 13, 0.65, 39 and 4.5 (ng/g fat wt.), respectively. Hg levels in liver and muscle samples from fin and Antarctic minke whales from the Antarctic Ocean were similar and these were one order of magnitude lower than those of fin whales from the western North Atlantic Ocean. Hg accumulation level in whales is affected by age, Hg levels in their prey items, and prey consumption. Hg levels in their prey items, such as fish and zooplankton, increase with trophic level. The ‘background’ levels of Hg in open oceans are comparatively similar around the world. Therefore, geographical differences of Hg levels among the same species could be caused by food habitats and/or age. Levels of OCs, except for HCB, in fin whales from the Antarctic Ocean were similar to those in the Antarctic minke whales. These levels were extremely lower than those in fin whales from the middle latitude of the northern hemisphere nearby human activity, and those in killer whales from the Antarctic Ocean. These results suggest that the OCs levels in whales could mainly be affected by prey position in the food chain and area. OCs levels in fin and Antarctic minke whales in the Antarctic Ocean could be the lowest among whale species in the world. HCB levels in large whales would be affected by trophic levels of its preys rather than the spatial differences.