Aquatic insects as bio-indicator of water quality- A study on Bakuamari stream, Chakras hila Wildlife Sanctuary, Assam, North East India

Abstract

The Chakrashila Wildlife Sanctuary (latitude 26° 15' - 26° 26' N and longitude 90° 15' - 90° 20' E) is located in western Assam. This study is a part of biomonitoring programme of the sanctuary using aquatic insects of Bakuamari stream during 2011- 2012. The study revealed presence of 21 species of aquatic insects belonging to 14 families and 7 orders. Different diversity indices were worked out in all the seasons. The environmental variables of water were estimated by standard methods. Pearson’s Correlation Coefficient was computed to find out significant correlations between diversity and density of aquatic insects with the water variables. Biomonitoring Working Party score and the Average Score per Taxon were calculated to find the status of the water quality of the system. Canonical correspondence analysis (CCA) was used to infer the relationship between environmental variables and aquatic insect community structure. The influence of environmental variables in the diversity of aquatic insects has been discussed in the paper.