Evaluation of River Water Quality Based on Biotic Index of Benthic Macroinvertebrate as Bioindicator (Case study in Genjong River Wlingi Blitar East Java, Indonesia)

This research aims to determine the water quality profile of Genjong River based on physicochemical parameters and benthic macroinvertebrates as bioindicators. Sampling was carried out at four different location difference human activity in surrounding. The sampling done triple repetition for each station. station 1 is ecotourism (as reference site or positive control this study), Station 2 (livestock I), 3 II), 4 (plantation). were measured including air temperature, current velocity discharge, conductivity, pH, DO, BOD, TSS, nitrate, orthophosphate. result from identification calculation density used some diversity indices biotic indices. value parameter tested by One-way ANOVA. Based abiotic profile, included Class IV category Indonesia Government Regulation No. 22 2021 with a BOD 3.61 – 7.22 mg.L-1. Human activities along have great impact decreasing indicated increasing nitrate levels 0.52 ± 0.07 mg.L-1 up 0.85 4. Also, orthophosphate 0.02 0.01 0.18 Meanwhile, bioindicators, classified lightly (S1, H = 1.74) moderately polluted (S4, 1.24) toxic materials slightly contaminated organic matter (S4 FBI 5.38). decline also shown ASPT 4.20 3.68