The objective of this study was to explore the applications of next generation sequencing in pollution source identification. Sediment samples were collected from several estuarine regions (Keiyaxi, Sanxinggongxi, Yangangxi, Errenxi), chemical characteristics, heavy metal contents, microbial diversity and functional genes related to copper resistance were analyzed in different depths. The Canonical Correlation Analysis showed that bacterial genus Bacteroidetes_vadinHA17_ge, GIF9_ge, JS1_ge, Methanolinea, Methanosaeta, Odinarchaeia_ge, Smithella, and Vibrio were positively correlated with the concentrations of cadmium, chromium, copper, lead, nickel and zinc at different depths of sediments. These bacrterial genus may be potential bioindicators for heavy metal pollution in the estuary regions. In addition, the metagnomic analysis showed that copper resistance genes which correlated with copper concentration were mainly P-type ATPase and multicopper oxidase, suggesting that detoxification (lowering toxicity by oxidizing monovalent copper copper to divalent one) and copper ion export are the major detoxification machanims for these microbial communities in estuaries. In addtion, the diversity and abundance of these resistance genes can be applied for pollution sources identification in the future.

estuarine sediment, heavy metal, vertical distribution, microbial community profile, next generation sequencing