OPEN SEA CAGE CULTURE PROSPECTS AND CHALLENGES – INDIAN SCENARIO
The unique combination of high quality protein, unsaturated fatty acids and vital nutrients makes fish an important food protein source in many developed and developing countries. Despite, the higher protein level in fish the world fish production is 140 million tons which is relatively lower than worlds cereals production of 2.2 billion tons. The total fish production of India is 10.16 mmt (2016-17) of which capture fishery contributes 3.59 mmt and culture fishery contributes 6.54 mmt. The per capita fish consumption of Indian population is about 5-6kg/year, which is comparatively lower to the world per capita consumption of 16.7kg/year.
The capture fisheries have also reached the maximum sustainable level and to meet the increasing demand, the expansion of aquaculture activities is essential, further expansion of land based aquaculture activity leads to competition for fertile land, freshwater sources, causing social and ecological issues. Land based culture produces average 0.5 kg/m3 (5,000 kg/ha.), whereas cage farming offers a production of 35kg/m3 ie 70 times more than pond production. Open sea cage farming has the added advantage of higher production with minimal environmental damage when compared to land based aquaculture. Indian has 8100 Km of coastline and there is a huge scope for open sea cage farming for culture of commercial important marine fish to meet the fish protein demand of the country. Realizing the potential benefits of open sea cage farming NIOT has successfully developed and deployed 9 m diameter HDPE floating collar cage with multipoint mooring in three different sea conditions viz. protected bay, North Bay (Andaman & Nicobar Islands), semi protected gulf Olaikuda, Rameswaram (TN) and unprotected open sea of the coast of Thuplipalem (Andhra Pradesh). NIOT has successfully cultured six potential marine finfishes like Cobia- Rachycentron canadum, seabass - Lates calcarifer, pampano - Trachinotus blochii, milk fish- Chanos chanos; parrot fish- Scarus ghobban and rabbit fish- Siganus spp in the open sea cages. Among the cultured fishes, Cobia- Rachycentron canadum showed the best performance with a growth rate of 15.4g /day and an average survival rate of 74%. Notably, the fishes attained an average weight of 4 kg in 325 days. The farm gate price of the harvested cobia fetched Rs. 325.00/ kg. The presentation will outline the experiences of multispecies offshore cage culture and the prospects of shaping it into a commercial venture.
