Status of fish diversity in Surha Taal, a natural lake in the floodplains of river Ganga, in Ballia District, Uttar Pradesh, India

Abstract

The study presents the status of fish diversity, abundance and habitat structure of Surha Lake, which is a perennial and natural lake fed by the river Ganga. The study was conducted between 2011 to 2013 covering pre and post-monsoon seasons. In total, 4,852 individual fish specimens were collected representing 66 fish species belonging to 23 families. The species diversity comprised 65 species in pre-monsoon and 60 species in post-monsoon season (p<0.05). The highest species diversity was recorded for the family Cyprinidae (22), followed by Bagridae (7). An assessment of conservation status of 66 fish species as per IUCN Red List 2019 criteria listed 6 species under near threatened (NT), 54 under least concern (LC) and two species under vulnerable (VU) category. The study reports several commercially important species under near threatened (Chitala chitala, Labeo pangusia, Ompok bimaculatus, Ompok pabda, , Ailia coila and Bagarius bagarius), which makes Surha Taal an important natural lake from fishery management point of view. The study also prioritised different habitat types important for different species. The slow water in the mid-channel areas of the lake were categorised as important habitats for near threatened and vulnerable fish species like C. chitala, B. bagarius and Wallago attu, which can be prioritised for population level management.