Freshwater fish diversity in the river Ken of Ganga basin: abundance, threats and their management.

Abstract

Systematic surveys were conducted to explore the diversity of freshwater fishes, distribution, abundance, trophic ecology and current threats of the fishes at different spatial scale of the river Ken, planned for interlinking in India. Altogether, 57 species representing 42 genera and 20 families were recorded for the first time from the studied river. Of the 57 species, seven belong to the ‘endangered’ category and 13 belong to the vulnerable category. Apart from Indian major carps, Tor tor, Bagarius bagarius, Chitala chitala, Pangasius pangasius, Sperata aor, Wallago attu, Ompok pabda, Ompok bimaculatus, Labeo calbasu, Channa marulius, and Macrognathus pancalus were the other important species. All the species have been reported for the first time in this river. Presence of a protected area and forest cover on the upper stretches of the river tends to have positive effect on the aquatic habitat which is reflected in high fish diversity as compared to lower stretches which is subjected to several anthropogenic activities. The distribution pattern, community dominance index, evenness index, similarity index and trophic ecology have been discussed. Some segment of the river showed the most diversified environmental structure and had the different fish communities. The results of this study would be useful to develop baseline information for a river, planned for river interlinking which enables predictions on the change/loss of the fish diversity in the post interlinking phases.