Anish Ratna Shakya

Project Description

Macroinvertebrates Diversity along Altitudinal Gradient in Kali Gandaki River
Abstract:River ecosystems are considered as one of the most endangered ecosystems in the world as they are increasingly threatened by synergic effects of local and regional stressors. Rivers in Nepal are also affected by a number of natural as well as anthropogenic stressors like climate change, over exploitation, flow modification and water pollution. Rivers harbour diverse aquatic communities and play crucial role in maintaining ecological balance. Among diverse aquatic biota, the assemblages and distribution of macroinvertebrates are ecologically and economically very important. The objective of the study was to generate a baseline data of macroinvertebrates diversity at different elevations along the Kali Gandaki River. A total of twenty two sampling sites were chosen with altitude ranging from the lowest 185 m (Narayani River) to highest 2,770 m (Kagbeni) on the basis of different ecoregions: Trans-Himalaya, Mountains, Hills and Lowlands. Selected physico-chemical parameters were measured using Hach test kit (Model AL-36B). Semi-quantitative sampling of macroinvertebrates was done using D-net in pools and riffles. Chi Squared Test of Independence was performed to see significant variation of the benthic faunal assemblages along the elevational gradient. NEPBIOS was applied to estimate the water quality class of the investigated sites. The macroinvertebrate assemblages were found to be varied at different elevations along the Kali Gandaki River attributed by the changes in physico-chemical parameters, sediment substrate and vegetation as well.