Drifting Behaviour of Aquatic Mites and Regulating Ecological Parameters in Khankragad Stream, A Springfed Trubutary of Alaknanda River, Rudrarayag, Garhwal, Uttarakhand, India

Abstract

Water mites are a large group of macroinvertebrates that are very vulnerable to contamination and environmental changes. As a result, they are often used to monitor water quality. Khankra gad stream, a third-order perennial spring-fed stream of the Alaknanda River in Uttarakhand, India, was studied to determine the drift behavior of water mites and water quality. Drift nets were set up for 24 hours in both spots of the Khankra stream where there was little or no human influence over a two-year sampling period (June 2018-20). Every four hours, the nets were changed out with new ones. Water mites signify a particular drift month and diel drift pattern. The majority of the drift mite species were present in considerably higher numbers in the daytime. During the two-year study period, a total of 2503 mite samples were collected from the Khankra stream, from which 204 water mite species drifted. The least number of Hydrachnidia (694) were collected from Spot-1, and the highest (1809) were collected from Spot-2, with 106 water mites drifting from Spot-1 and 134 mites drifting from Spot-2 during the study period. From Spot-2 maximum 25 mite species were collected and minimum 19 mite species were collected from Spot-1. For various mite species, the DBDI value ranged from 0.155 (July) to 0.204 (April) in Spot-1 and 0.134 (July) to 0.149 (February) in Spot-2. It was also observed that maximum water mite species were day-drifter. The physico-chemical parameters of the Khankra stream were also reported. The effect of ecological parameters on mite drift was investigated using Canonical correspondence analysis (CCA).