Study on Impacty of Irrigation Dam on Fish and Fishery of Kesali River, Morang, Nepal.

Abstract

The present work was conducted in Kesali River close to irrigation dam. The study was focused in the analysis of physicochemical parameters of water, biological studies like diversity and population of fishes. The different implements and techniques used in fishing in this area were also recorded. The basic objective of present study was to assess the impact of irrigational dam on fish diversity and population.

Altogether 21 species of fishes was recorded in present study belonging to 15 genera, 10 families and under 5 orders. Fish composition and frequency distribution of fish catches revealed majority fishes belonged to Cyprinidae family and Puntius species as most dominant species followed by common species such as Barilius sp, Garra sp, Channa sp, and Colissa fasciatus. Amphipnous cuchia was least recorded and reported in this river. The sampling record showed fish diversity high in upstream of dam during November and February but high fish diversity was recorded in downstream of dam during May and August. The highest fish catch per unit hour was recorded in August and lowest in November.

Both conventional and non-conventional fishing methods were noted to be used in and around the Kesali river area. The use of most of the fishing appliances were recorded seasonal; but some implements like cast net, chhanki net, hook and line were found to be used throughout the year. Fish diversity and population is declining day by day due to development work (damming), non conventional fishing methods, pollution and natural calamities like heavy flood and erosion.

People living around Kesali Rive were found to be involved in fishing only as part-time fisherman, but fisherman from India were found to be fishing throughout the year.