Environmental exposure and ecological risk of heavy metals in fishing harbors of the Pearl River Delta, South China

Abstract

Fishing harbors are widely distributed in coastal regions in China. However, few studies about pollution by heavy metals in those fishing harbors have been reported. In this study, a total of 49 surface sediment samples were collected from nine harbors along the coastline of China to illuminate heavy metals pollution and their potential ecological risk. Results indicated that Cu, Pb, Zn and Cd are four main elements causing pollution with high concentrations detected in the selected harbors. These four metals from three harbors located in the Pearl River Delta are remarkably higher than those in other regions. The main finding of the study is that Cu was observed with rather high concentration in sediments, with the highest up to 1249 mg kg−1. Cu is widely used in antifouling paint for fishing ships, which may have been released into seawater and accumulated in marine sediment. High correlations of Cu, Pb and Zn with total organic carbon in sediments from these harbors indicate that the harbors may act as an important heavy metals source to the coastal environment of China. The potential ecological risk posed by Cu and Cd in the harbors of the Pearl River Delta region is from moderate to very high. Hence, there is an urgent need for more studies in this area.