香港汀角红树植物、沉积物及双壳类动物重金属含量

Heavy metals contents in sediments, mangroves and bivalves from Ting Kok, Hong Kong.

汀角有香港面积最大的硬底质红树林,作者调查了该红树林区沉积物、红树植物以及双壳类动物体内重金属(Cu、Pb、Zn和Ni)的含量.总体看,沉积物中重金属含量与其他地点相比较低,红树植物根际沉积物中重金属含量高于光滩.红树植物组织内重金属含量较低,体内Pb、Zn的含量均低于根际沉积物,但对Cu、Ni有一定的富集,Cu可在根部和叶内富集,而Ni只在根部富集,并束缚于此.双壳类动物对4种重金属的吸收存在较大差异,Zn、Cu的富集明显高于Pb和Ni的富集程度.5种动物中又以岩蠔最高,体内的Zn、Cu分别达到3913, 378mg/g.从重金属含量看,作为食用动物有一定的风险.

Ting Kok has largest hard-bottom mangal in Hong Kong. We investigated the contents of heavy metals (Cu, Pb, Zn and Ni) in sediments, plant tissues as well and edible parts of bivalves in this mangrove area. Compared to other sites, contents of heavy metals were low in mudflat sediments of Ting Kok. Contents of heavy metals in sediments around the roots of mangrove species were higher than those in mudflat. Lead and zinc contents in tissues of mangrove species were lower than in sediments, but copper and nickel were higher in plant tissues. Cu was mainly accumulated in roots and leaves whereas Ni was mainly accumulated in roots. Bivalves accumulated much more Zn and Cu than Pb and Ni. Saccostrea cucullata had highest contents of heavy metals among the five bivalves, and contents of Zn and Cu were 3913 and 378mg/g respectively. Our results indicated that there were some risks eating the bivalves.