Synopsis The present book entitled "Mahseer fish Bionomics and Population: Barrage Impact on Fish Biology" reflects the impact assessment of barrage on Mahseer fish biology mainly in terms of present status of fish diversity in upstream as well downstream of Ganga river, fish catch and population size, biometry, age migratory and reproductry behaviours. The book includes seven chapters covering in depth analysis of mahseer fish biology in depth analysis of masher fish biology and suggested all possible conservation measures for habitat restoration to enhance the mahseer population in Ganga river flowing in the foot hills of Garhwal region of Uttaranchal. The book forms a usefull contribution for fisheries scientists, zoologists, aquaculturists, sport fish anglers, environmentalist, researchers, students of fisheries sciences and for the people engaged in the field of conservation biology and serve as a guide and inspire future research on mahseer biology.