Occurrence of organochlorine pollutants in the eggs and dropping-amended soil of Antarctic large animals and its ecological significance

摘要

Persistent organochlorine pollutants (POPs) are analyzed for the dropping-amended soils from the habitats of Antarctic seabirds and seals in Fildes Peninsula and Ardley Island. The concentration ranges are 0.21 to 3.85 ng/g for polychlorinated biphenyls (ΣPCBs), 0.09 to 2.01 ng/g for organochlorine pesticides (ΣDDT), and 0.06 to 0.76 ng/g for hexachlorocyclohexanes (HCHs). Among these, hepata-chlorobiphenyls, hexachlorobiphenyls, p,p'-DDE and α-HCHcompounds are dominant. The concentration ranges of ΣPCB, DDT and HCH in the eggs of skuas were 91.9—515.5 ng/g, 56.6—304.4 ng/g and 0.5—2.0 ng/g respectively; those in the eggs of penguins were 0.4—0.9 ng/g, 2.4—10.3 ng/g and 0.1 — 0.4 ng/g; and those in the eggs of giant petrel were 38.1 —81.7 ng/g, 12.7—53.7 ng/g and 0.5—1.5 ng/g respectively. The dominant POP compounds in the eggs are PCB180, PCB153, p,p'-DDE and hexa-chlorobenzene (HCB). The present study shows that the concentration of POPs in the seabird-inhabited-dropping-amended soil varies with the extent of predation and nest occupancy of different seabird populations. Statistical analysis on the POP concentrations from the different seabird eggs implies that the difference in the bio-concentration levels of the birds depends on the bio-habits of the species, such as the range of activity, distance of immigration, feeding pattern, and nest occupation. Among these, the most important factor is the location of the seabirds in the food chain and their feeding pattern. This shows that POPs accumulated in the seabirds resulted from the bio-concentration through the food chain. In addtion, ~(210)Pb dating for the dropping-amended soils (AD1-a and AD2) was performed, which provided the POP accumulation rate and the historic record for the soil profile. It indicates that POP will continuously affect the Antarctic ecosystem for a long time.