SEASONAL VARIATIONS OF MERCURY AND ARSENICCONTENTS IN OYSTER(OSTREA PLICATULA) IN XINGANG HARBOUR, TIANJIN
天津新港褶牡蛎体内Hg和As含量的季节变化

The seasonal variations of mercury and arsenic in oyster, Ostrea plicatula, in Xingang Harbour, Tianjin, have been investigated to study the effects of the metals on the animals and assess the environmental quality. The samples were randomly collected once a month from May, 1983 to February, 1984, and the sites of sampling were in an area at 1.5 killometer long and 3 meter wide, to the east of the point (7 + 985) an the North Mole (see Fig. 1). 40-50 oysters with 5-10 cm sheel length were used each time. The animals were dissected, and the soft tisseles with body fluid were homogenized. A part of the homogenate was weiqled and wet ashed, and the mercury in it was determined with 590 mercurydeter-mination meter. Another part of homogenate was dry ashed, and the arshic was determined with 721 spectrophotometer. The results showed that the mercury contents in the oysters were higher in autumn and winter than that in summer, but the arsnic contents were higher from late spring through summer than in winter. The concentrations of mercury and arsnic in the oysters varied from 0.118 to 0.235 and from 12.0 to 25.98, with mean concentrations of 0.183 and 19.46 mg/kg, (dry weight), respectively.