汞、DDT、六六六在蓟运河河口生态系中的迁移、积累与循环

在蓟运河河口生态系统中,水生生物对汞、DDT、六六六均有很强的积累能力,体内积累量大体上有沿生物营养等级而增高的趋势,尤以汞最为明显。汞在浮游生物、底栖动物、草食性鱼类、杂食性鱼类、肉食性鱼类及水鸟体内的平均含量分别为0.34、0.48、0.90、1.28、1.70和3.29mg/kg。 六六六的浓缩因子较小(10~2),且易于排出;DDT的积累能力最强(10~4),但在生物体内易转化成毒性较小的DDE和DDD;汞有较强的富集能力(10~3),可在生态系统中循环住复。

TRANSPORT, ACCUMULATION AND CIRCULATIONOF MERCURY, DDT AND BHC IN ECOLOGICALSYSTEM IN ESTUARY OF JIYUN RIVER

Mercury, DDT and BHC accumulate strongly in aquatic organisms and bear a direct ratio to the trophic level and mercury is more than the other two. Mercury concentrations in planktons, benthos, herbivorous fish, omnivorous fish, carnivorous fish and water fowl in vivo are 0.34, 0.48, 0.90, 1.28, 1.70 and 3.29 ppm, respectively, in estuary of Jiyun Riyer.The concentration factor of BHC is small(102) and easy to be removed, while that of DDT accumulates in big amount (104), but DDT may be easily transformed into DDE and DDD, toxicity of which keeps at low level in vivo. Concentration of mercury also retains a large amount (103), and mercury is found recycling in the ecosystem over and over.