Macroinvertebrate Community as Bioindicator of Water Quality of Tambis River, Palompon, Leyte, Philippines

Macroinvertebrates have been used globally as bioindicators of water quality of rivers due to their varying tolerance to pollution. The water quality of Tambis River in Palompon, Leyte, Philippines was determined using macroinvertebrates and selected physico-chemical and ecological assessments. Employing kick-sampling method, three sampling stations were established based on the surrounding land use (forested, agricultural, and near residential). Twenty-seven macroinvertebrate families were identified. Permutational multivariate analysis of variance (PERMANOVA) revealed a significant difference in the benthic macroinvertebrate families across three stations (p=0.001). There was a decrease in the abundance of pollution-sensitive families from the forested station towards the downstream, closest to the residential area. Sensitive Ephemerellidae and tolerant Thiaridae were the most abundant in the forested and downstream area respectively. The highest diversity and evenness were observed from the agricultural area. Stream Invertebrate Grade Number - Average Level (SIGNAL 2) scores were plotted declined in all quadrants, suggesting good water quality to moderately polluted. Water temperature, pH, and velocity were the most influencing environmental variables to the macroinvertebrate assemblage as revealed by the Canonical Correspondence Analysis (CCA). Overall, the water quality of Tambis River ranged from being of good quality to moderately polluted. The data obtained in this study could serve as a baseline in providing information to formulate and implement scientific-based regulatory measures towards the conservation of Tambis River.