India ranks second in culture and third in capture fisheries production and is one of the leading nations in marine products export. The present marine fisheries scenario is characterized by declining yields from the inshore waters and increasing conflicts among different stakeholders, whereas the increasing demand for fish in domestic and export markets indicate good prospects for large scale sea farming and coastal mariculture. The mariculture potential of India is vast as there is great scope for developing farming of shrimps, pearl oysters, mussels, crabs, lobsters, sea bass, groupers, mullets, milkfish, rabbitfish, sea cucumber, ornamental fishes, seaweeds etc. Although about 1.2 million ha is suitable for land based saline aquaculture in India, currently only 13 % is utilized. In India till date mariculture activities are confined only to coastal brackishwater aquaculture, chiefly shrimp farming.
Mariculture potential in India
Area | Total Area | Potential cultivable area (million ha) | Current cultivable area (million ha) | Current annual production |
Coastal land based | 2.5 | 1.2 | 0.14 | 85,000(mainly Shrimps) |
Hinterland saline soil aquifer based | 8.5 | - | 100 | 200(Mlkfish,Mullets,Pearlspot,Scampi) |
Open sea farming | 202 | 1.8(in shore 0-50 meter depth) | 20 | 1,500(Mussels) |
Bays, coves and gulf | - | 10,700 | - | - |
Estuaries and backwaters | - | 2,050 | 5 | 800(oysters) |
Depending on the geographical and ecological diversities of the country, there are vast differences in the availability and suitability of areas that can be developed for mariculture and also in the candidate species available for cultivation. Species like shrimps and the finfish like grey mullets, milkfish, pearl spot, seabass, groupers, redsnapper, breams and pompanos are suitable for farming all along the Indian coast especially along the south west and south east coasts.
Open sea cage culture
The open sea cage culture has been expanding in recent years on a global basis and it is viewed by many stakeholders in the industry as the aquaculture system of the millennium. Cage culture has made possible the large-scale production of commercial finfish in many parts of the world and can be considered as the most efficient and economical way of rising fish. It has now been realized that further conversion of wetlands and mangroves into traditional aquaculture farms has to be limited. Cage culture has several advantages over other culture systems. The cage culture system can optimize the carrying capacity per unit area since the flow of current brings in fresh water and removes metabolic wastes, excess feed and faecal matter. Simple cage designs for inshore waters are relatively easy to construct with minimal skilled labour. Cage culture is a low input farming practice with high economic return. The Indian coast offers many ideal locations for cage farming.
In the area of marine fish culture, the country is still in the experimental phase only. Attempts are being made to develop suitable hatchery and farming technology for mullets (Mugil cephalus, Liza macrolepis, V. seheli), groupers (Epinephelus tauvina), seabass (Lates calcarifer), milkfish (Chanos chanos) and pearlspot (Etroplus suratensis). The Central Institute of Brackishwater Aquaculture (CIBA) has developed an indigenous hatchery technology for seabass using captive broodstock. Some of the seafishes that are grown in India and those that have immense potential from Kerala’s perspective is dealt herein.