Tien-Hsi Fang

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 x 10(7)t/y; Mn, 9.07 x 10(5)t/y; Zn, 1.08 x 10(5)t/y; Ni, 4.48 x 10(4)t/y; Pb, 4.32 x 10(4)t/y and Cu, 3.1 x 10(4)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.

Trace metal contents in male, non-ovigerous and ovigerous females, and the egg sacs of the marine copepod, Euchaeta concinna Dana, 1849 (Copepoda, Euchaetidae), collected from the southern East China Sea

Marine copepods have a great ability to accumulate trace metals from seawater. The trace metal content in marine copepods may vary both intra- and inter-specifically. However, the known specific trace metal content of the copepod sexes and according to the ovigerous status of the females is very limited. Copepod samples of Euchaeta concinna Dana, 1849, were collected from the southern East China Sea and separated into four groups: males; non-ovigerous females; ovigerous females without egg sacs, and egg sacs, in order to analyse the trace metal contents (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in these samples. These trace metal contents were found to range between 0.04 and 195.7 μg/g. Zinc, Fe, and Cu were the major components among the trace metals studied and their concentrations generally exceeded 10 μg/g. The trace metal contents in the copepod body generally exceeded the amount in the egg sacs. However, the Cr concentration in the egg sacs was much higher than that in the copepod body, either male or female, and the value ranked as second just behind Zn among the metals studied. The nickel content was also slightly higher in the egg sacs. This study provides the important finding that E. concinna egg sacs contained Cr concentrations out of all proportions to that of the copepod body. Yet, why E. concinna egg sacs contain relatively higher Cr concentrations than the body remains a question to be answered.