Xinghua Bay Research Articles

Organochlorine pesticide and heavy metal residues in some edible biota collected from Quanzhou Bay and Xinghua Bay, Southeast China

In order to assess the contamination of edible marine organisms in Quanzhou and Xinghua Bays, Fujian Province, China, concentrations of organochlorine pesticides (hexachlorocyclohexane isomers or HCHs and dichlorodiphenyltrichloroethane isomers/derivatives or DDTs) and heavy metals (Cu, Pb, Zn, As, Cr, Cd, Ni and Hg) in 13 species collected from different sites in the bays were analyzed by GC-ECD and ICP-MS. The concentration of the sum of DDTs exceeded that the sum of HCHs in the samples. Most of the organisms showed higher levels of DDTs than the first level criterion (10 ng/g) for marine biological quality in China (GB 18421-2001) but conformed to the first level criterion (20 ng/g) for HCHs. The estimated mean daily uptake of pesticides was below the level for minimal risk to the consumers. The levels of Cd, As and Pb in most organisms from both bays were markedly elevated and above the recommended legal limits for human consumption. Our results showed the need for routine monitoring of marine species contamination to ensure public and environmental health.

Distribution and ecological risk evaluation of organochlorine pesticides in sediments from Xinghua Bay, China

The concentrations of organochlorine pesticides (OCPs) in sediments from Xinghua (兴化) Bay, Fujian (福建) Province, China, were determined. The OCP concentrations ranged from 2.48 to 313.88 ng/g, with a more serious contamination in the upper sediment. But the OCP concentration in the upper layer was less than that in the lower sediment at the exit of the bay due to the influence of the Coriolis force. At the joint of the internal and external bays, OCPs accumulated abundantly because of freshwater and seawater mingling. The isomer percentage combined with isomer ratios indicated that DDTs (dichlorodiphengltrichloroethanes) were mainly derived from long-term weather soils, while lindane was introduced recently to the bay. The rivers flowing into the bay contributed more to DDT and HCH (hexachlorocyclohexane) contamination, especially at low tide. Compared with the corresponding quality guidelines from Ingersoll, the sediments from Xinghua Bay were likely to pose biological impairment and should be taken into account.

Distribution of radioisotopes in sediment cores from nearshore off Xinghua Bay mouth, Fujian, China

Two marine sediment cores were collected from nearshore off Xinghua Bay mouth in Fujian, China and the 40K, 137Cs, 210Pb, 226Ra, 228Ra, 228Th and 238U in the cores were measured using γ-spectroscopy. For the core ZK6, the activities of 40K were vertically homogeneous within measured error in the whole core and 226Ra, 228Ra and 228Th showed large vertical variations with the same tendency. The sedimentation rates were 0.400 cm·y−1 above 50 cm and 0.737 cm·y−1 below depth of 50 cm. The change of sedimentation rates indicates the heterotaxy, which was justified by the absence of 137Cs in the zone of 25–50 cm. For core ZK6, the sedimentation rate was 0.179 cm·y−1. Vertical distributions of 40K, 226Ra, 228Ra, 228Th and 238U in the core ZK18 are similar to each other although there were significant large variations with depth. The large variations of radioisotopes with depth in the cores mean that the sediment cores have been disturbed largely due to marine environment change. The mean activities of radioisotopes in the core ZK6 are higher than ZK18 that may be ascribed to different hydrodynamic environments.