TRANSPORT, ACCUMULATION AND CIRCULATIONOF MERCURY, DDT AND BHC IN ECOLOGICALSYSTEM IN ESTUARY OF JIYUN RIVER
汞、DDT、六六六在蓟运河河口生态系中的迁移、积累与循环

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.