Use of benthic diatom indices for assessing ecological status of the Sai Gon river, Vietnam

Abstract

In the present study, the Biological diatom index (BDI) and the Trophic diatom index (TDI) were calculated for the assessment the ecological status and the water quality of the Sai Gon river in comparison with the physico-chemical variables. In addition, a multivariate method was used to elucidate the main environmental variables driving the diatom community. A total of 87 diatom species were identified and used to calculate the diatom indices. The results of the biological data indicate that ecological status of upstream has a fine water quality; however, the downstream of the river was moderately polluted, and in some cases, of poor status. Canonical correspondence analysis (CCA) permutation tests demonstrated that diatom community was divided into two groups that corresponded to rural and urban characteristics. The BDI and TDI indices showed sensitivity to environmental stressors and served as potential application for bio-monitoring and water quality assessment of surface water in tropical region.