In India, West Bengal is the leading state in hatchery-based seed production (spawn, fry, advanced fry) of major carps and other economically important freshwater fishes. Dissolved oxygen is the most critical parameter of water quality and basic necessity in fish hatcheries, nursery and grow-out ponds. Hatchery fish seed production can be limited by the dissolved oxygen content of circulating water. Progressive fish breeders in villages of West Bengal have overcome and eliminated this problem by designing simple but effective means of water aeration to improve dissolved oxygen in hatchery water supplies, maximising survival of fertilised eggs, hatchlings and spawn. This article describes some of the techniques that have been adopted using low-cost and recycled materials.
