Research On Heavy Metals From Marine Sediments?Large Yellow Croaker And Sea Bass Near Ningbo And Zhoushan

Ningbo and zhoushan are located in eastern Zhejiang.With developed economy?industrial base and marine aquaculture,the water environmental pollution has become increasingly serious.The heavy metals pollution with high toxicity and the health risks of aquatic products in the area have attracted much attention.In this paper,the sediment and fish samples were collected and analyzed from 5 mariculture areas near Ningbo and Zhoushan The contents of heavy metals from sediment and fish samples are used for the selection of aquaculture waters and the risks of fish consumption.The main results are as follows:(1)The concentrations of Cu,Zn,Cr,Cd,Pb,Ni,As,Hg in the study area were lower than the Chinese national sediment quality standards(GB 18668-2002).The average values of heavy metals were higher than the regional background concentrations except Cr and Ni.Cd shows a serious pollution in sediment.(2)The contents of heavy metals in different tissues and organs of fish were different.Heavy metals were mainly accumulated in livers and gills except Hg.The contents of heavy metals in fish muscles were lower than the national standard limits.(3)Based on the potential ecological risk index of heavy metals in the sediments of the study area,the average ecological risk was 295.16 closing to the "strong" ecological risk level.Cd and Hg are the main contribution elements,respectively accounted for 71.06%and 17.9%;Based on target hazard quotient,the THQ and TTHQ in the muscle of large yellow croaker and sea bass were less than 1,which are safe for consumption.(4)Based on the correlation analysis of heavy metals in sediments and fish tissues and organs,the results showed that there was a significant positive correlation between the contents of heavy metals in sediments and fish.The accumulation of Cd in the livers of large yellow croaker and sea bass is strong,which can be used as the indicator organism of Cd.