镉、汞、铅和石油烃复合污染对渤海湾常见渔业资源生物的影响初探

Effects of the Combined Pollution of Cd,Hg,Pb and Petroleum Hydrocarbons on Common Fishery Species in the Bohai Bay

通过对1996～2005年渤海湾近岸海域海水镉、汞、铅和石油烃浓度变化的分析,发现海水中镉浓度呈明显上升趋势,汞、铅和石油烃则无明显变化趋势.加速生命试验法模型(Accelerated Life Testing model)的研究显示,1996～2005年渤海湾近岸海域海水镉、汞和铅平均浓度均已超过其对渤海湾常见渔业资源生物的安全浓度.镉、汞、铅和石油烃对生物的长期致死率鱼类分别为4.5%、16.3%、0.0%和12.0%,甲壳类为0.4%、7.9%、0.3%和6.6%,双壳类为10.5%、0.2%、0.2%和2.3%.效应加和模型(Independence Action model)的估算表明,在镉、汞、铅和石油烃组成的复合污染条件下,渤海湾常见鱼类、甲壳类和双壳类的长期死亡率分别为29.7%、14.6%和12.9%,其种群增长率分别降低约6.4%、14.6%和12.9%.与镉、汞、铅和石油烃单种污染物暴露相比,其复合污染导致的渤海湾常见渔业资源生物种群(鱼类、甲壳类和双壳类)增长率的降低更明显.因此,复合污染是导致渤海湾渔业资源衰退的重要因素。

Concentrations of Cd,Hg,Pb and petroleum hydrocarbons（PHs）in seawaters of the Bohai Bay during 1996～2005 have been discussed.It is found that Cd exhibited an increasing trend during this period,and that Hg,Pb and PHs didn＇t exhibit an obvious trend during the same time.Accelerated Life Testing model shows that the annual mean concentrations of Cd,Hg and Pb in seawaters of the Bohai Bay during 1996～2005 were higher than the safe concentrations of them to common fishery species in the Bohai Bay.The long-term lethality of Cd,Hg,Pb and PHs to fishes is 4.5%,16.3%,0.0% and 12.0%,respectively,that to crustaceans is 0.4%,7.9%,0.3% and 6.6%,respectively,and that to bivalves is 10.5%,0.2%,0.2% and 2.3%,respectively.Using Independence Addition model,it is estimated that the long-term lethality of Cd,Hg,Pb and PHs to fishes,crustaceans and bivalves is 29.7%,14.6% and 12.9%,respectively,which results in the reduction of population growth rate by about 6.4%,14.6% and 12.9%,respectively.Compared with the single exposure of Cd,Hg,Pb and PHs,the combined toxicity of them resulted in larger reduction of population growth rate of common fishery species in the Bohai Bay.Therefore,combined pollution is an important factor affecting the fishery decline in the Bohai Bay.