Distribution and contamination of trace metals in surface sediments of the East China Sea

The distributions, contamination status and annual sedimentation flux of trace metals in surface sediments of the East China Sea (ECS) were studied. Higher concentrations of the studied metals were generally found in the inner shelf and the concentrations decreased seaward. The sequences of the enrichment factor (EF) of the studied metals are Cu > Mn > Ni > Zn > Pb > Fe. The values of EF suggest that the metals contamination in the middle and outer shelves of the ECS is still minor. The annual sedimentation fluxes of trace metals in the ECS were: Fe, 3.48 × 107 t/y; Mn, 9.07 × 105 t/y; Zn, 1.08 × 105 t/y; Ni, 4.48 × 104 t/y; Pb, 4.32 × 104 t/y and Cu, 3.1 × 104 t/y, respectively. Approximately 55–70% and 10–17% of the sedimentation fluxes of trace metals were deposited in the inner shelf and the Changjiang estuarine zone.