India has about 8118 Km. of coastal line and nearly 2 million Sq Km of Exclusive Economic Zone (EEZ) and half a million Sq Km. of Continental Shelf. From these marine resources, India has an estimated fisheries potential of 4.41 million tonnes. Similarly, we have 3.15 million hectares of reservoirs, 2.5 million hectares of ponds and tanks, 1.25 million hectares of brackish water area, cold water resources of hilly states and all other inland fishery resources offer a production potential of about 15 million tonnes. Against this potential, the production of fish from inland sector was mere 7.77 million tonnes during 2016-17. In this context, optimum utilization of resources becomes pivotal to achieve the targeted production. It is against this backdrop that we want to harness all possibilities for intensive and integrated development of fishery sector.
Responsibility of the DADF for fisheries development:
The Department of Animal Husbandry, Dairying & Fisheries (DADF), Ministry of Agriculture and Farmers Welfare which is responsible for fisheries development and management in the country, formulates developmental strategies for the sector and issues policy guidelines for Fisheries and Aquaculture development and management. It also provides technical and financial assistance for implementation of fishery development schemes to various States/UTs and other implementing agencies.
Marine capture fisheries:
Marine capture fisheries is undergoing tremendous changes due to increasing fishing effort. The catch of almost all commercially important marine fin fishes and shell fishes is on the decline trend and result in severe resource depletion and unemployment. Decline in marine capture fishery also affects the availability of cheap protein for the public and also affects the GDP growth of the country. It was in this context that mariculture including open sea cage farming of fin fishes and shell fishes assume importance.
What is Mariculture?
Mariculture is a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, or in tanks, ponds or raceways which are filled with seawater. An example is the farming of marine fish, including finfish and shellfish like cobia, pompano, sea bass, lobster, oysters and seaweed in salt water resources. Non-food products produced by mariculture include: fish meal, nutrient agar, jewellery (e.g. cultured pearls), and cosmetics. Fish raised through mariculture practices are perceived to be of higher quality than fish raised in ponds or tanks, and offer more diverse choice of species.
What is open sea cage culture?
Open sea cage farming is eco-friendly and done in open sea where wave action is less. The fishes that are being cultured in cages are high value fishes; hence there is huge export demand for cage cultured fishes. Cage is an enclosure, which can be of any shape or size wherein culture of biotic organisms, such as fin fish and shell fish is being practiced in captivity with a stipulated objective. The cages are totally enclosed on all sides, except leaving an opening at the top for providing feed. Size of a sea cage can vary from 6 -12 m dia for fish farming in open sea, where the wave and tidal impact is suitable for farming. A series of cages are spaced in a battery for better operation.
Initiatives and status of Mariculture practices in India:
A. Marine Finfish Culture:
(i) Cobia (Rachycentron canadum):
Cobia is one of the suitable species for open sea cage farming. It can grow to about 3-4 kg body weight in one year and 8-10 kg in two years. Brood stock development of cobia was initiated by CMFRI at Mandapam during 2007-08. The technology of cobia seed production and farming was standardised by CMFRI and is being taken up by fish farmers successfully. The successful sea cage farming of cobia by the ‘Cobia Farming Association’ in Palk Bay region, Rameswaram and subsequent adoption by many fishermen groups at Tamil Nadu, Kerala, Karnataka and Goa indicated that the technology is commercially viable. At Mandapam-Rameswaram area currently more than 50 cages are deployed for cobia farming by fishermen groups. There is a great demand for seed to deploy further cages for cobia farming.
(ii) Sea bass (Lates calcarifer):
Sea bass is one of the most important candidate species for open sea cage culture and pond culture and has high commercial value. Seed production technology has been developed and standardised by the ICAR Institutes. Protocol for nursery and rearing of Sea bass are developed by CMFRI and CIBA. Several cage and pond farming demonstrations were done successfully. CMFRI has perfected cage culture of Sea bass at Karwar in Karnataka and has successively proved production to the tune of about 3tonnes fishes from a 6 meter diameter cage. Sea bass seeds are produced in the hatcheries of Rajiv Gandhi Centre for Aquaculture (RGCA) and CIBA. However the hatchery production meets less than 40% of the demand. Sea bass is successfully farmed along Maharashtra, Goa, Karnataka, Tamil Nadu, Andhra Pradesh and Kerala coasts.
(iii) Silver pompano (Trachinotus blotchii):
Silver pompano is also a suitable species for marine aquaculture due to itsvide acceptability and medium size suitable for a small family. It has the ability to accustom to take pellet feeds, wide tolerance to water quality and high market demand. The CMFRI has achieved successful brood stock development, induction of spawning and larval production of silver pompano. The technology of silver pompano seed production and farming developed and standardised by CMFRI during 2011-15 was taken up by fish farmers successfully.The techno economic viability of coastal pond farming of silver pompano was also demonstrated by the CMFRI during 2012 in Andhra Pradesh. Silver pompano is found to grow faster in low salinities (10-25 ppt), less cannibalistic and more resistant to wide range of diseases and commands good price in the domestic and international markets. Pompano seeds were supplied to many farmers in Tamil Nadu, Andhra Pradesh, Kerala, Karnataka, Goa, Gujarat and West Bengal for commercial culture.
(iv) CMFRI has also attempted some research on seed production technologies for the following species
a) Epinepheles coioides – Cage farming across east and west coast b) Lethrinus lentjan – Cage farming along west and east coast c) Gnathanodon speciosus – Seed production is successfully being carried out d) Trachinotus mookalee - Seed production is successfully being carried out e) Lutjanus argentimaculatus – Breeding and seed production is being attempted.
(v) Way forward for commercialization of Mariculture of Sea bass, Cobia and Pompano are :
a) Establishment of brood-banks b) Establishment of hatcheries c) Establishment of land based nurseries d) Feed production Technology e) Construction of Cage farms f) Establishment of land based support facilities including cold chain and processing g) Marketing strategies (a) Components for establishment of brood banks are: • Establishment of brood-banks • Bio-secure Brood-stock production • Production of required newly hatched larvae • Supply to Pilot hatcheries (b) Components for establishment of Finfish hatcheries are: • Establishment of hatcheries through state departments • Establishment of required nurseries • Supply of ready-to-stock fingerlings to fishermen/farmers These activities can be established through State agencies and private entrepreneurs. (c) Commercialization of Sea cage/pond Farming: • Selection of prospective farmers, farm sites and imparting training at research institutions, empowerment and continued support through NFDB till they become self-sustainable • Identification and empowerment of feed manufacturer/ supplier for supplying good quality marine finfish feed at subsidized price to farmers. Constraints for developing cage farming business: • Non-availability of quality seeds of high value finfish • Want of suitable sitesfor cage culture. • Lack of high quality formulated feeds • Lack of sea cage farming / leasing policies B. Oyster and Mussel farming: The Asian green mussel, Perna viridis is a significant resource of Indian coast. Recent years have witnessed an increased demand for mussels especially in Northern Kerala and Goa. CMFRI has developed technologies for oyster and mussel farming on commercial scale. Advantages of these farming are: • Short grow out period of 4 to 5 months as compared to 18 to 24 months in Europe and America • Lower trophic level advantage, simple technology – easily adoptable • Raw materials (wooden poles, nylon rope and seed) are locally available. • Good domestic market in Kerala, Karnataka, Maharashtra, Goa etc. • Suitable for women empowerment in Maharashtra, Goa, Karnataka, Tamil Nadu and Andhra Pradesh. • Potential for development and export of value added products Oyster farming: • Seasonal group farming activity in Kerala • Small-scale aquaculture units of 20 to 24 sq.m • Benefits more than 500 families Constraints in Mussel and Oyster farming: • Methods suitable for seed collection from open sea are yet to be developed • Social conflict between common resource users like fishers and farmers (eg. Conflict between mussel farmers and mussel fishers in Kasargod district regarding collection of seed by farmers from natural beds) • Presence of bio toxins due to sudden harmful algal blooms • Lack of common depuration facilities in villages. Lack of storage facilities for holding harvested mussels in villages. • Lack of leasing rights • Poaching of farm stock in open sea farming • Since the practice is mainly confined to brackish-water bodies the carrying capacities have not been convinced to the farmers resulting in environmental problems C. Crab fattening of Mud crab (Scylla serrata) • Commercial level seed production technique and economically viable farming methodology need to be improved. • Fattening practice to selected farmers in Kerala, Karnataka and Tamil Nadu. • ‘Water crabs’ (freshly moulted crabs) of 550 g and above are stocked and maintained for a period of 3 to 4 weeks for hardening the shell thereby increasing their commercial value. • Scylla serrata and S. tranquebarica are high valued crabs for which fattening procedures has been developed. • Crabs are fed with trash fish @ 5 to 10% of the biomass / day thrice daily at regular intervals. • Harvested after 3 to 4 weeks • Wild collection of seed not resource friendly D. Lobster fattening • Lobsters weighing an average 80 g weight can be fattened to above 100 g within a month (Threefold increase in price). Lobsters weighing below 100 g take 5-6 months to attain 300 g in a grow out operation. • Constraint: Collection of juveniles from wild is not resources friendly. Hatchery techniques for seed production not yet ready. • Panulirus homarus, P.ornatus and P. polyphagus are the main species having high value in the export market. • Fast growing and highly adaptable to culture conditions. • CMFRI has successfully demonstrated spiny lobster fattening in floating sea cages at Vizhinjam, Veraval and Mandapam. E. Seaweed farming • Global production 10.1 million tonnes worth US $ 5.6 billion • Technologies developed are yet to be commercialized except for Kappaphycus alvarezii. • Raw material for seaweed based cottage industries for agar and alginates only from natural harvest. • Village linked seaweed farming programs initiated in the villages near Mandapam with technical help from CMFRI. • Commercial farming of Kappaphycus alvarezii carrageenan yielding seaweed is getting expanded in Ramanathapuram and Tuticorin areas of Tamil Nadu. Strengths • Easily adoptable farming techniques • Market demand for seaweeds mainly from cottage industries • Industry needs 2000 tonnes (dry wt.) of agarophytes; now available only 800 tonnes to 1100 tonnes Drawbacks • Grazing of farm crops by fishes • Low returns from monoculture of seaweeds and inconsistent yields • Non availability of seaweed seed stock with high yield of colloids • Poor quality (gel strength) of polysaccharides from Indian seaweeds. F. Strategies for business opportunities: a) Need to establish Brood stock centers for Cobia, Pompano and Sea bass b) Hatcheries for production of seed of Cobia, Pompano and Sea bass c) Nursery rearing centers for production of ready to stock fingerlings of Cobia, Pompano and Sea bass d) Development of cage/pond farms for Cobia, Pompano and Sea bass e) Production of grow out feeds for Cobia, Pompano and Sea bass f) Fabrication of site specific and cost effective cages and mooring systems g) Establishment of hatcheries for green mussel, edible oyster and pearl oyster h) Farming systems for green mussel, edible oyster and pearl oyster i) Hatcheries for marine ornamental species j) Conditioning centers for green certified wild collected ornamental species trade k) Selection of suitable sites for farming l) Production of seaweeds through farming m) Commercial level production of designer pearls n) Development of commercial level Integrated Multi-Trophic Aquaculture. Systems (IMTA) systems o) Grow out Production through Recirculation aquaculture systems G. Way forward for development of Mariculture sector in India • An integrated effort is needed by linking up the entrepreneurs, fisheries development agencies, State/UT Fisheries Departments and Marine and Brackish water Fisheries Research Institutions with regard to financial, technical and marketing aspects. • Effective handholding is needed for the entrepreneurs to get themselves established in the sector. • A coordinated and synchronised action by empowering the entrepreneurs in the available business opportunities together can create a farmed seafood production sector in the country in the near future.