Determination of the Relationship Between River Ecosystems and Benthic Macroinvertebrate Ecological Indices as a Basis for River Health Assessment

Abstract

In Malaysia, physical and chemical components have been used as an indicator for river health monitoring and rehabilitation programme for many years as a basis and reference without any proven successful results. Therefore, this study aims to identify the relationship between river ecosystems and benthic macroinvertebrate ecological indices for river health assessment. There were a total of five sampling sites selected along Sungai Mengkibol, Sungai Madek and Sungai Dengar in Johor. Benthic macroinvertebrates and six in-situ parameters were collected and measured. Meanwhile, riparian river compositions, canopy cover, large woody debris, substrate compositions and velocity were measured for assessing the river habitat. Ecological indices were analysed and correlated with other parameters. The results obtained reaffirms that river discharge had an influence (p < 0.05) on the composition of the benthic macroinvertebrates caught in the sampling area. Rivers that have reached canopy cover recorded a higher diversity, richness, evenness indices and EPT taxa compared to the least or those of poor canopy cover. The results obtained from the chi-square test shows that there is a significant association (p < 0.05) between physicochemical water quality with dominance index, evenness index and EPT composition. Thus, it can be concluded that benthic macroinvertebrates can be used as bio-indicator to assess river health.