Temporal Variations and Fluxes of Suspended Particulate Matter and Trace Heavy Metals in Early Summer at Yatsu Tidal Flat, Japan

Abstract

The temporal variations of concentrations and fluxes of suspended particulate matter (SPM) and trace heavy metals of Fe, Pb, Cu, Zn and Cd were investigated at the Yatsu tidal flat connected to Tokyo Bay via the Yatsu and the Takase Channels in early summer, 2003. The inflow flux of SPM from Tokyo Bay to the tidal flat was greater than the outflow flux; the SPM was considered to be trapped on the tidal flat by a physicochemical cohesive force and biological functions. The heavy metals were transported as particulate and dissolved phases in the fluxes. In the fluxes of both of the channels, the particulate heavy metals were predominantly Fe, Pb and Zn, while the particulate and the dissolved heavy metals were equally attributed to Cu. The Pb, Zn and Cd contents in the SPM were higher than the contents of those dissolved in the flux, although the Fe and Cu contents were relatively low. Pb would be preferentially adsorbed to the SPM compared with Cu, whereas concentrations of both these elements were similar in dissolved phases.