Polybrominated diphenyl ethers in birds from Chongming Island, Yangtze estuary, China: insight into migratory...

Sum-PBDEs concentrations in shorebirds and Anatidae ducks muscles from Chongming Dongtan National Nature Reserve ranged from 21-324 to 14-159ngg(-1) lw, respectively. PBDEs were detected in muscles of all the studied species. Compared with flyways around the world, migratory waterbirds on the East Asian-Australasian flyway exhibited lower PBDEs burdens than those reported on Black Sea-Mediterranean flyway in Europe and Pacific, Atlantic, Mississippi flyway in North America. Residential Eurasian tree sparrow samples indicated few PBDE products were used in Chongming Island developed in the idea of world famous eco-island. There was no significant difference in PBDEs concentrations between shorebirds and ducks. However, PBDEs composition varied between them. BDE 209 (29-44%) contributed to sum-PBDEs more than BDE 47 (17-19%) in muscles of ducks, while BDE 47 was the predominant congener in shorebirds contributing 32-48%. Stable nitrogen and carbon isotopes and stomach content analysis indicated shorebirds and ducks had the same dietary composition, but showed different preference to bivalves, gastropods and crustaceans for shorebirds and aquatic plant material for ducks. Migratory species had inherent migratory routes and thus had exposure to PBDEs during their stay in breeding grounds, stopover sites and wintering grounds with high use of different commercial PBDE mixtures. Higher percentage of BDE 209 in ducks than shorebirds suggested that breeding ranges and wintering grounds of ducks comprise wetlands in inland and coastal China and Korea where decaBDEs pollution was serious in Asian-Pacific region. Our findings reveal the influence of migratory behavior on PBDEs distribution in migratory waterbirds.