DISTRIBUTION OF Sn AND Bi IN THE SEAWATER OF NORTHWEST PACIFIC AND EQUATOR

The average concentration of total Sn in surface layer is 2.90 μg/1 and that of total Bi 0.50 μg/1.The free ion, bound and particulate forms of Sn in Changjiang (Yangtze River) Estuary account for 20%, 30% and 50% of the total Sn respectively, and those of Bi 25%, 35% and 40% respectively.In the surface water of the Pacific, the total Sn is 2.06 μg/1, and the percentages of the three forms of Sn are 50, 30 and 20% respectively.The total Bi are 0.38 μg/1, and the percentages of the three forms of Bi are 55, 25 and 20% respectively.The concentrations of free ions of Sn and Bi in 0-1400 m and 0-1900 m in 18 and 19 stations are in vertical homogeneous distribution.The slight similarity in distribution between Bi ion and salinity may be due to the influence of organisms and biochemistry.