长江口潮滩大型底栖动物对重金属的累积特征

选择长江口滨岸潮滩最具代表性的4个岸段，在广泛的样方调查基础上，对比分析不同样点生物量较大的几种大型底栖动物体内的重金属含量，计算单位面积的潮滩中大型底栖动物对重金属的吸收量，并对河蚬和缢蛏的生物质量进行评价.结果表明，河蚬是长江口滨岸潮滩分布最广的大型底栖动物，其软体组织对Cu、Mn和Zn有明显的富集作用，秋季时BSAFs值分别达2.01、1.41和2.85；河蚬对Cu具有明显的选择性吸收作用，不同岸段河蚬体内Cu含量差异不大.软体动物麂眼螺和泥螺幼体以及所有甲壳动物对Cu有明显的富集作用，BSAFs值达2.97～7.97.单位面积的泥螺幼体对Cu、Pb、Fe和Cr的吸收量明显高于其它底栖动物，对Mn、Zn的吸收量仅少于浒浦的河蚬.与我国海洋生物的质量标准相比，长江口滨岸潮滩底栖贝类的生物质量总体较好.

Heavy metals accumulation in macrobenthos in intertidal flat of Yangtze Estuary

In April, July and November 2002 and April 2003, a quadrat investigation of macrobenthos was conducted at four sampling profiles in the intertidal flat of Yangtze Estuary. The concentrations of Cu, Pb, Fe, Mn, Zn and Cr in several high biomass macrobenthos were determined, their absorbed amounts per square meter were calculated, and the biological quality of Corbicula fluminea and Siliqua minima was evaluated. The results showed that C. fluminea was widespread in the intertidal, especially in the low tidal flat of Yangtze Estuary, and heavy metals were mainly concentrated in its soft tissues. C. flurninea could selectively absorb Cu, leading to the little variation of Cu concentration in the tissues of C. flurninea sampled from different coastal region. Mollusks Rissoina sp. and Bullacta exarata, and all crustaceans could markedly accumulate Cu in their bodies, and the BSAF value reached 2.97- 7.97. The mollusks and crustaceans had the greatest absorption of Fe per square meter, followed by Mn, Zn and Cu, and Pb and Cr. The amount of Cu, Pb, Feand Cr absorbed by B. exarata larva from per square meter intertidal flat was obviously higher than that by other macrobenthos, while the absorbed amount of Mn and Zn in B. exarata larva was less than that in C. fluminea collected from XuPu. The concentrations of Pb and Cr in the soft tissues of C. fluminea and S. minima were relatively lower in the intertidal flat of Yangtze Estuary than in other coastal and estuarine areas, and those of Cu and Zn were also low but at appreciable level. Compared to the criterion for marine biological quality in China, the edible soft tissue of Corbicula fluminea and .S. minima in the tidal flat of Yangtze Estuary was relatively safe for human beings.