Statistical analysis of accumulation patterns of heavy metals in biota from the Pearl River Estuary, South China

Abstract

The object of this study was to identify the accumulation patterns of Cu, Pb, Zn and Cd in different consumers living in the Pearl River Estuary. Concentrations of metals in water, sediments and tissues of demersal fish, crustaceans and molluscs were determined. Cluster analysis and principal component analysis were used to evaluate accumulation patterns of these four metals among species. Fish species were clustered as a group which was characterized by low accumulation of Cu, Zn and Cd. By contrast, crustaceans and molluscs were clustered to another group which was characterized by high accumulation of Cu, Zn and Cd. However, no significant difference of Pb accumulation between the two groups was identified. In addition, the concentrations of the four metals in fish were strongly correlated with metal concentrations in sediments, indicating that the sediment was the source of heavy metals in fish. Moreover, the accumulation of a heavy metal in fish was correlated with the same metal element and other heavy metals in the sediments. This may demonstrate a tendency of cross-acclimation in fish to different metals within the special habitat from the Pearl River Estuary. Dietary attention should be paid to the high concentrations of Pb in fish and crustaceans.