Effects of emerging pollutants and heavy metals on the variation of bacterial communities in estuary sediments

Emerging contaminants (ECs) and heavy metals (HMs) are universal in estuarine sediments and their effects on microbial communities have been widely studied as separate factor, rather than co-existence environmental factors. In this study, the combined effects of ECs and HMs on microbial communities were investigated in sediments from 11 major rivers estuaries around the Bohai Sea, China. Proteobacteria, Bacteroidetes and Firmicutes were the dominant phylum in the sediments. Being significantly correlated with Shannon index, total phosphorus and total organic carbon were proposed to affect microbial community structure. Redundancy analysis of microbial variation could be explained by pollutions, among them, the impact of Cd and As were greatest, followed by Mn, Fe, Zn and Cu, nothing about galaxolide and tonalide. However, correlation analysis found that the concentration of ECs could increase the abundance of certain bacteria, which can be used as potential contamination indicators. Overall, microbial composition in the major estuaries around the Bohai Sea exhibited spatial variation and functional diversity according to environmental factors, which is used to predict of the changes in estuary ecosystems and maintain their ecological balance and health.