香港汀角紅樹植物、沉積物及雙殼類動物重金屬含量

汀角有香港面積最大的硬底質紅樹林，作者調查了該紅樹林區沉積物、紅樹植物以及雙殼類動物體內重金屬 (Cu、Pb、Zn和Ni) 的含量。總體看，沉積物中重金屬含量與其他地點相比較低，紅樹植物根際沉積物中重金屬含量高於光灘。紅樹植物組織內重金屬含量較低，體內Pb、Zn的含量均低於根際沉積物，但對Cu、Ni有一定的富集，Cu可在根部和葉內富集，而Ni只在根部富集，並束縛於此。雙殼類動物對4種重金屬的吸收存在較大差異，Zn、Cu的富集明顯高於Pb和Ni的富集程度.5種動物中又以岩蠔最高，體內的Zn、Cu分別達到3913， 378mg/g。從重金屬含量看，作為食用動物有一定的風險。
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 378µg/g respectively. Our results indicated that there were some risks eating the bivalves. Copyright © 2003 中國環境科學編輯部.