Linking Benthic Macroinvertebrates and Physicochemical Variables for Water Quality Assessment in Lower Dongnai River System, Vietnam

Abstract

The benthic macroinvertebrates living on the bottom channels are one of the most promising of the potential indicators of river health for the Lower Dongnai River System with hydrochemistry playing a supporting role. An evaluation of the interrelationships within this approach deems necessary. This work identified and tested these relationships to improve the method for water quality assessment. Data from over 10,000 km2 watershed were used as a representative example for Lower Dongnai River and tributaries. The data covered the period March, 2007 to 2010. To implement this evaluation, the analyses were based on accepted MRC method and the studies of scientific group for the biological status assessment. Selected environmental variables were compared with ecological indices, based on benthic macroinvertebrates. Correlation analyses showed significant relationships. The highest scores were found for organic pollution (dissolved oxygen, biological oxygen demand), nutrients (total nitrogen, total phosphorus), and microorganisms (coliform, E. coli). Both univariate and multivariate analyses were used to examine the ecological quality of the Lower Dongnai River System using benthic macroinvertebrates seems to be the most sensitive indicator to correlate with physicochemical variables. This demonstrated that it could be applied to describe the water quality in the Lower Dongnai River System.