title: Development and validation of a bacteria-based index of biotic integrity for assessing the ecological status of urban rivers: A case study of Qinhuai River basin in Nanjing, China.
abstract: With the increasing human disturbance to urban rivers, the extinction and biodiversity losses of some macroorganism species decreased the accuracy of bioassessment. In this study, a novel index of biotic integrity based on bacteria (Ba-IBI) was first developed for Qinhuai River in Nanjing city, China. Thirty-two biofilm samples were collected along the river bank and the bacterial communities were identified by high-throughput sequencing. By the range, responsive, and redundancy tests, four core metrics were selected from the dataset of 78 candidate metrics, including Pielou's evenness index, proportion of Paenibacillus, proportion of OTUs tolerant to organic pollution and proportion of Nitrosomonas. The results showed that the Ba-IBI was able to effectively discriminate different impaired site groups, and had a good correlation with the index of water quality (r = 0.79, p < 0.01) and the qualitative habitat evaluation index (r = 0.51, p < 0.01). Moreover, the Ba-IBI was negatively correlated with the number of population within a 1 km buffer (r = -0.71, p < 0.01). Application of the index showed that most of the sites were in the poor or bad class in the river. Our study revealed that the Ba-IBI is an effective and reliable approach for assessing the ecological status of Qinhuai River basin, which can complement the existing ecological assessment approaches for urban rivers. Meanwhile, repeted surveys and field validations are still needed to further improve the applicability of the index in future studies.
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China. Electronic address: envly@hhu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Hydrology Bureau of Changjiang Water Resources Commission, Wuhan, Hubei, 430010, PR China.
authors.forename: Bao
authors.initials: B
authors.lastname: Qian
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Niu
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Hainan
authors.initials: H
authors.lastname: Wu
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Peifang
authors.initials: P
authors.lastname: Wang
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
mesh_terms: D001419:Bacteria; D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring; D006801:Humans; D045483:Rivers
keywords: Bacteria indicator; Bioassessment; Index of biotic integrity; Qinhuai River; Urbanization