Monitoring and assessment of anthropogenic impacts on water quality by estimating the BMWP and ASPT indices for a headwater stream in Doon Valley, India

The current study was conducted to evaluate the impact of anthropogenic stresses on physico-chemical attributes and the abundance of macroinvertebrates during a period of one year from November 2017 to October 2018. Two important sampling sites (reference site S1; impacted site S2) characterized by various human activities were identified along the river. Anthropogenic activities were common at the impacted site (S2). High concentrations of TDS, phosphates, nitrates, sodium, turbidity, and conductivity were recorded at site S2. Based on Pearson’s correlation coefficient and canonical correspondence analysis, a few parameters including the dissolved oxygen, water velocity, TDS, turbidity, pH and nitrates shape the taxonomic order and species of macroinvertebrate in the Baldi River. The dominance of species under Ephemeroptera, Plecoptera, and Trichoptera orders at site S1 indicated the stress-free conditions, whereas an increase in the density of Oligochaeta and Diptera (Chrimonoids) at site S2 represented serious anthropogenic stress condition. Lower values of biotic indices (Shannon–Weiner diversity index, EPT %, BMWP, and ASPT) also indicated a disturbance at site S2. Degradation in water quality, decrease in the dominance of Ephemeroptera, Plecoptera, and Trichoptera, and an increase in Annelids and Chrimonoids are the key factors that reflect anthropogenic stress on the Baldi River.