Fish farming is the principal form of aquaculture, while other methods may fall under mariculture. Fish farming involves raising fish commercially in tanks or enclosures, usually for food. There are two kinds of aquaculture: extensive aquaculture based on local photosynthetic production and intensive aquaculture, in which the fish are fed with external food supply. The management of these two kinds of aquaculture systems is completely different.
India is a large producer of inland fish, ranking next only to Japan. Out of the total inland fish production of over 3.6 million metric tons, more than 60% is contributed by fish culture in ponds and reservoirs. The average productivity from ponds on the national level is around 2,500 kg/ha/year, though in Andhra Pradesh and Haryana it is more than 5,000 kg/ha/year, while in some other states like Bihar and UP it is anywhere between 1,500 and 2,500 kg/ha/year. Fish culture is adopted by all kinds of farmers – small and marginal ones, relatively larger farmers and those who do it on commercial scale.
Coastal aquaculture is a significant contributor to aquaculture production. This is mainly composed of shrimps (Penaeus monodon and P. Indicus) and other species cultured like lobster, crab, molluscan (edible oyster, pearl oyster, mussel and clam), sea cucumber, marine finfish (mullets, groupers, seabass, milkfish and pearlspot) and seaweed. Among these culture systems, the yield, operating cost and net profit from shrimp farming are highest. The yield from shrimp farming is around (3.12 t/ha), followed by polyculture of mud crab farming (1.14 t/ha crabs and 0.7 t/ha milkfish), edible oyster farming (0.8 t/ha meats) and monoculture of mud crab farming (0.78 t/ha crabs).
The major freshwater farming environments in India are pond, cage, pen, rice field, sewage feed and air breathing. Polyculture is the dominant culture system practiced. The major species are carp, freshwater prawn and catfish. Basically India's aquaculture is carp-oriented and the contribution of other species is marginal. Fish culture in India can be classified as extensive, semi-intensive or intensive and stocking rate is high at 18,408 fish/ha. The average yield varies according to species group, level of input use and intensity level. Cost structure is primarily composed of lease cost of the water body, cost of inputs (fertilizer, seed, and feed), management and harvesting. Lease value varies according to the fertility and property and management regimes of the water body. The cost of inputs varies according to intensity of their use across different technologies in accordance with requirements. Both the central and state governments have come up with schemes to help the cause of the farmers. The aquaculture production contributes greatly to the Indian exports.Of the total exports, European Union countries accounted for 35 percent, Japan 16 percent and the US 13 percent. India’s share in global marine product market is about two percent. With good demand in the overseas markets and changing consumption patterns in the Japanese market, exports of seafood from India are expected to grow in the coming years.
Fish culture is practiced in less than 30 percent of the total areas available. With an abundance of freshwater resources, India has still not been able to tap even 30% of the potential area for inland fish production. This sector has a potential to create huge market, provided fish cultivation is done on a scientific basis.