Studies on ecology, fish diversity and fisheries of Ken–Betwa rivers (India): Proposed for inter-linking

Abstract

The Ken and Betwa rivers traversing through Central India are the major tributaries of the river Yamuna. Both rivers originate above 550 m above sea level in the Vindhya region. An interlinking project proposed for the rivers envisages diversion of water from Ken basin to the Betwa. The river sediment is alkaline and dominated by sand (78–89%) in both rivers. Oxygen-rich alkaline water and moderate values of chemical parameters show the pollution free and productive nature of both the rivers. There was no statistically significant difference in water quality between the Ken and Betwa rivers, except for total alkalinity. The biotic parameters were observed in similar ranges and moderate condition. A total of 61 planktonic forms were recorded from the rivers out of which 55 were phytoplankton. For the first time, 89 fish species belonging to 10 orders, 26 families, and 62 genera have been recorded in the river Ken, while 81 species classified under 10 orders, 24 families, and 55 genera were found in the Betwa. Exotic fish species were also observed in the downstream stretches of both rivers. Out of the total fish species, 77 were common to both rivers, 12 were found only in the Ken River, and 4 species were restricted to the Betwa. Analysis of relative abundance showed dominance of Labeo boggut in the Ken and Osteobrama cotio in the Betwa River. On comparison of the Shannon–Wiener Diversity and Evenness Indices of fish diversity, these indicated slightly higher values in the Ken (3.76 and 0.842) than the Betwa (3.66 and 0.835). A total of nine near-threatened fish species was recorded in the rivers. Both rivers have already been obstructed by many developmental projects; the proposed interlinking would further negatively impact the ecology and fisheries.

Keywords:

• sediment
• water quality
• biotic communities
• impacts

Acknowledgements

The authors are grateful to the esteemed reviewers for their critical comments and suggestions in improving the manuscript.