Regulating fluvial systems by dams, barrages and construction of inter-basin link canals, has severe impacts on fish populations across the world’s rivers. In India, all major fluvial systems are interrupted by a series of barriers. This includes small weirs to large dams and salt-water barriers preventing saline incursion to the estuarine lakes. One major reason for decline in the populations of commercially important and ecologically unique fish species has been the blocking of migratory routes of spawners to upstreams or to the estuarine areas.