Cage fish culture is a practice of growing fish in confined areas, which facilitate feeding, harvesting and other management procedures. It has been established as an intensive fish farming system. Cages made of wood or steel frames, covered with mesh or nets, are kept immersed in natural water bodies. Little fish, or fingerlings, of different varieties such as sea bass, grouper or cobia are put into these cages and provided with feed regularly until they grow to a marketable size of 6-8 inches.
India, with its abundant water bodies, including the backwaters, estuaries and offshore sea, offers tremendous potential for cage farming. This method is prevalent and quite successful in Vietnam and Scandinavian countries. Marine Products Development Authority (MPEDA), the government body with the mandate to promote and exports fish resources, is looking to promote cage farming in India in a big way.
The agency has signed a memorandum of understanding (MoU) with the Norwegian state-owned Innovation Norway. The latter will lend technical assistance for the promotion of cage culture in India. Norwegian experts, after a survey of Indian waters for more than a year, have begun cage farming on a trial basis in the Andamans, Ratnagiri in Maharashtra and Padana in Kasargod district of Kerala.
Meanwhile, a charitable organisation based in Ernakulam District has successfully conducted cage farming in Sathar Island, Moothakunnam.
It was implemented by Kottapuram Integrated Development Society (KIDS) with the collaboration of the department of fisheries - Kerala, Cochin University of Science and Technology (CUSAT), ASR Marine consultancy and New Zealand Aid for International Development (NZAID) at the confluence of the right arm of the Periyar River with the Arabian Sea.
They were successful in rearing Asian Seabass (Lates calcarifer) and the fish attained an average weight of 650 gm in just six months. The project utilised self-help groups of inland fishermen who were constrained with the declining resources of inland waters.
It is reported that Vietnam earns a revenue of $1 billion annually from cage culture. Given the several deep-water bodies across India, there is a need to promote cage farming in a scientific way, sources said. A study on water quality, current and depth has to be conducted in the area before cage farming can begin. Because of the extremely capital-intensive nature, it may not be possible for India to have large cages, as in Norway or some other Scandinavian countries. MPEDA plans to have smaller cages, which can hold up to 200 fish.
Estimates point to an initial capital investment of Rs 6.2 lakh per cage that can last for at least five to six seasons.
The average season is around eight months, during which the fingerlings grow. Annual income from each cage, calculated on conservative levels, could be around Rs 12,500 and a hectare of water area could hold nearly 100 cages. Since no antibiotics are used, these fish can fetch higher prices. Wooden cages, which last for lesser time, but are cost-effective, can also be used for cage farming.