Bio-assessment of River Ujh using benthic macro-invertebrates as bioindicators, India

Abstract

ABSTRACTRapid bio-assessment of River Ujh has been carried out using benthic macro-invertebrates based on the Hindu-Kush Himalayan (HKH) rapid field bio-assessment protocol. Meanwhile, the assessment of water quality in the river was performed using the weighted arithmetic water quality index (WA-WQI), based on physiochemical parameters. Furthermore, the biotic indices (such as Nepalese Biotic Score (NEPBIOS), modified NEPBIOS, HKHBIOS, Stream Invertebrate Grade Number-Average Level (SIGNAL), SIGNAL 2, biological monitoring working party and biological water quality class criteria) were used for biological assessment of water quality. The water samples were collected from eight sampling stations during the month of February in year 2015. The results indicate that the overall water quality in the river was poor (i.e. not suitable for drinking), as average WA-WQI was 78.65 in the sampling month. During the analysis of micro-invertebrate occurrence, a total of 10 taxonomic groups, 36 families and 2193 individual organisms were identified. Among all organisms, the members of taxonomic groups Ephemeroptera and Trichoptera were found in abundance at all sampling stations. However, the NEPBIO score was found to be decreasing from 6.1 at first sampling stations (S1, located in upstream) to 4.8 at last (S8, located in downstream), which indicate the decline in abundance of organisms due to deterioration of water quality in the river. Therefore, it has been suggested the river water must be treated prior to use for drinking. It is recommended that biotic indices developed for bio-assessment of water bodies in the central Himalayan region can also be applied suitably to assess the water quality status in River Ujh.