Diversity of aquatic insects and biomonitoring of water quality in the upper Ganga River, a Ramsar site: a preliminary assessment

Kritish De,Syed Ainul Hussain,Arkojyoti Sarkar,Kritika Singh,Virendra Prasad Uniyal,Jeyaraj Antony Johnson

doi:10.11609/jott.5458.13.13.20011-20018

Kritish De, Syed Ainul Hussain + Show 4 more

Open Access

https://doi.org/10.11609/jott.5458.13.13.20011-20018

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Abstract

Monitoring of freshwater habitats through aquatic insects is widely used. A study was carried out in March, 2019 at 14 sites in the Upper Ganga River between Brijghat and Narora, a riverine Ramsar site in India, to document the diversity of three major aquatic predatory insect groups—Odonata, Coleoptera, and Hemiptera—and determine their biomonitoring potential. The study recorded three species of Coleoptera, four Hemiptera, 14 dragonflies, and eight damselflies. The Shannon diversity index (H′) ranged from 2.465 to 2.782, Pielou’s Evenness index (J′) from 0.841 to 0.894, and Berger–Parker index of dominance (d) from 0.122 to 0.243. Families Libellulidae (Odonata), Coenagrionidae (Odonata) and Gerridae (Hemiptera) had high relative abundance and dominant status. The stream invertebrate grade number-average level (SIGNAL2) score (for family) ranged from 2.316 to 3.174, lying within quadrant 2 of the SIGNAL2 (family) quadrant diagram. This suggested that the water in the area is likely to have high levels of turbidity, salinity, or nutrients, caused naturally or by anthropogenic activities, and the water has low levels of most toxic chemicals.

Highlights

MATERIALS AND METHODSFreshwater habitats occupy 1% of the earth’s surface (Strayer & Dudgeon 2010), and in addition to supporting many species freshwater ecosystems provide goods and services of critical importance to human societies
For the assessment of the bioindicator potential of the insects, SIGNAL2 score was used which is a family-level water pollution index based on the known tolerances of aquatic macro-invertebrate families to various pollutants which has a gradient from 1 to 10 (Chessman et al 1995)
The SIGNAL2 scores were plotted in a quadrant diagram (SIGNAL2 score in the y axis and the numbers of families in the x axis) which includes four quadrants

Summary

Introduction

MATERIALS AND METHODSFreshwater habitats occupy 1% of the earth’s surface (Strayer & Dudgeon 2010), and in addition to supporting many species freshwater ecosystems provide goods and services of critical importance to human societies. Acknowledgements: The authors are thankful to: the National Mission for Clean Ganga, Ministry of Jal Shakti, Department of Water Resources, River Development and Ganga Rejuvenation, Government of India for sponsoring the work under the project ‘Biodiversity conservation and Ganga Rejuvenation’; the director and dean, Wildlife Institute of India, for their administrative support for the study; the Environment, Forest and Climate Change Department, Government of Uttar Pradesh for necessary support during fieldwork.

Results

Conclusion