A review of migratory activity in fishes reveals that migration is important for the completion of life cycle. Recent studies have increasingly demonstrated the wide spread existence of spatio-temporal variations in the abundance and distribution of species of freshwater fishes, previously assumed not to move between habitats. These movements are often for spawning, feeding and refuge, and in many cases are fundamental for the successful completion of life cycles. Chemical and physical changes in water environment affect the migration of fish. Most fish undertake feeding, breeding or wintering migrations. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture on fish migration
