『Abstract
　The heavy metal inventory and the ecological risk of estuarine sediments in Hailing Bay, an important maricultural zone along the southern coast of China, were investigated. Results show that the surface sediments were mainly polluted by As (2.17-20.34 mg/kg), Ni (1.37-42.50 mg/kg), Cu (1.21-58.84 mg/kg) and Zn (11.69-219.22 mg/kg). Furthermore, the aquafarming zone was significant more polluted than the non-aquafarming zone, and cluster analysis suggested additional sources of heavy metal input in the aquafarming zone. As, Cr, Cu, Ni, Pb and Zn were mainly present in the non-bioavailable residual form in the surface sediments, whereas Cd was predominantly in the highly acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from As, Cu and Pb to less degrees. The highest potential risks occurred near the aquaculture base, indicating the need to control heavy metal inputs from aquafarming activities.

Keywords: Heavy metal; Sediment pollution; Aquafarming; Chemical speciation; Risk assessment』

1. Introduction
2. Materials and methods
3. Results and discussion
　3.1. Heavy metals in surface sediments
　3.2. Heavy metals in sediment cores
　3.3. Ecological risk assessment
4. Conclusion and recommendation
Acknowledgement
References