Aquaculture technology has provided a means of augmenting supply of natural fish from oceans and fresh water bodies and thousands of farms that produce different species of fish are able to precisely control the conditions under which fish is reared. While wild fish takes time to replenish itself, lack of restraint on fishing invariably results in over fishing and extinction of many species. Interestingly a country like India unwittingly put in place a ban of trawling by mechanized boats for two moths during Monsoon to allow adequate time for regeneration. Whatever is done past records show that wild fish harvesting is not growing in tune with the demand for fish and world is increasingly looking at aquaculture to augment availability.Fish species like Carps, Salmon etc and crustaceans like shrimp are raised by the fish farms and this industry is consistently registering a growth rate of 8-10% annually. Herbivorous fish are much more efficient with the plant material they eat than are herbivorous farm animals. It is estimated that to produce 1kg of fish protein, less than 13.5 kg of grain is used while it takes 61.1kg of grain for beef protein and 38kg for pork protein. There is considerable pressure on land for growing grains to feed cattle while food grains for humans also will have to come from the land. Consider the health benefits of eating more fish and reducing meat consumption that will benefit the mankind immensely. There are serious environmental impacts, such as greenhouse gas emissions, eutrophication of water, and for species such as salmon the need for wild fish to feed the farmed ones. Carp fish that China produces is still considered environmentally disastrous though the impact is confined to local level.