The pathway and fate of the heavy metal mixture in Xiamen marine experiment enclosures

The pathway and fate of heavy metals were studied in 10m³ enclosures at Xiamen Bay in 1985.The dissolved metals added are removed rather quickly during the first days, and their half-removal times (t_1/2) (d) are as follows:Pb 5.4-5.8, Hg 6.7-14, Zn 11-22, Cu 16-29, and Cd 30-89.Zinc is transferred biologically to particles during phytoplankton bloom.The main Fate of added metals after 27 days is as follows; over 80% Cd and 60% Cu remain in dissolved phase, more than 60% Pb and 50% Hg transfer to settling settlement, while Zn is equally distributed in dissolved phase and settling settlement.The wall uptake is less than 2% of the total metals added.Organic materials play an essential role in the partition and the transfer of heavy metals in water column.Terrigenous and autochthonous particles show different affinities to different metals.Most heavy metals associate weakly with zooplankton.The Binding of Cd, Pb, Zn and Cu to the particles shows distinctive features related to the diagenetic alteration.