Kinetics And Physiological Effects Of Heavy Metals In Ostrea Rivularis

With the development of modern industry and agriculture, coastal marine environment was increasingly polluted by heavy metals. Ostrea rivularis can concentrate heavy metals in sea water in a very short time because of their ability of bioaccumulation, which is harmful to itself. More importantly, those heavy metals will be biomagnified and transferred along with food chain. Thus it will threaten the health of human beings.The study was conducted under fresh sea water, natural illumination and suitable temperature. The results from the study on accumulation and depuration of O.rivularis to Cu, Pb, Zn and Cd were as follows: The patterns that Cu, Pb, Zn and Cd absorbed by O. rivularis were all net accumulation, and they were all continuously accumulated by O. rivularis in the body throughout exposure, and correlations of the regression line (P<0.01) indicate that accumulation was linear with time. Increasing salinity in water and feeding mixed algae of Platymonas subcordiformis and Microalgae Chlorella sp. were of benefit to depuration of these heavy metals from O.rivularis in general.The results from the study on the effects of metals on superoxide dismutase (SOD) of O. rivularis were as follows: Cu Pb Zn and Cd all could induce the activity of SOD both in gill and digestive gland. The models of the activity of SOD induced by different concentrations of Pb and Zn both in gill and digestive gland were parabola. The models induced by different concentrations of Cu and Cd in gill didn't accord with parabola, while did in digestive gland. The activity of SOD in gill was increased greatly with the exposure of low concentration of Cd (0.1mg/L) within the exposure time. While at middle (0.5mg/L) and high concentration (1.5mg/L), the activity of SOD was induced significantly in the initial period, and later it went down rapidly within the exposure time. In digestive gland, the activity of SOD was induced significantly by low and middle concentration of Cd within the exposure time, and was incread greatly in a short time but went down rapidly within the exposure time under high concentration of Cd. The toxicities of the metals were ranged as Cd>Cu>Pb>Zn.