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DESCRIPTIONFish 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. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species used in fish farming are carp, salmon, tilapia and catfish. There is an increasing demand for fish and fish protein, which has resulted in widespread overfishing in wild fisheries. Fish farming offers fish marketers another source. However, farming carnivorous fish, such as salmon, does not always reduce pressure on wild fisheries, since carnivorous farmed fish are usually fed fishmeal and fish oil extracted from wild forage fish. The global returns for fish farming recorded by the FAO in 2008 totalled 33.8 million tonnes worth about $US 60 billion. Specific types of fish farms[edit source | editbeta] Within intensive and extensive aquaculture methods, there are numerous specific types of fish farms; each has benefits and applications unique to its design. Cage system[edit source | editbeta] Giant gourami is often raised in cages in central Thailand Fish cages are placed in lakes, bayous, ponds, rivers or oceans to contain and protect fish until they can be harvested. The method is also called "off-shore cultivation " when the cages are placed in the sea. They can be constructed of a wide variety of components. Fish are stocked in cages, artificially fed, and harvested when they reach market size. A few advantages of fish farming with cages are that many types of waters can be used (rivers, lakes, filled quarries, etc.), many types of fish can be raised, and fish farming can co-exist with sport fishing and other water uses. Cage farming of fishes in open seas is also gaining popularity. Concerns of disease, poaching, poor water quality, etc., lead some to believe that in general, pond systems are easier to manage and simpler to start. Also, past occurrences of cage-failures leading to escapes, have raised concern regarding the culture of non-native fish species in open-water cages. Even though the cage-industry has made numerous technological advances in cage construction in recent years, the concern for escapes remains valid. Main article: Copper alloys in aquaculture Recently, copper alloys have become important netting materials in aquaculture. Copper alloys are antimicrobial, that is, they destroy bacteria, viruses, fungi, algae, and other microbes. In the marine environment, the antimicrobial/algaecidal properties of copper alloys prevent biofouling, which can briefly be described as the undesirable accumulation, adhesion, and growth of microorganisms, plants, algae, tube worms, barnacles, mollusks, and other organisms. S.S. Presents Made By Siddhartha Satyakama.
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2. Fish Farming Capture & Culture Fishing Marine Fisheries Mariculture Inland Fisheries Composite Fish farming Quality Fish Seed 3. Fish is a cheap source of animal protein. 4. Enclosures like tanks are used to produce fish for commercial purposes, called fish farming. 5. Catla Rohu 6. Prawn Molluscs 7. Capture Fishing Culture Fishing 8. Capture Fishing: Capture fishing involves obtaining fish from natural resources. Like in sea water or fresh water. Culture Fishing: Culture fishing involves culturing the fish in small enclosures. 9. Fishing Marine Fishery Inland Fishery 10. Fishing in saltwater regions is called Marine Fisheries. Mariculture involves culturing of fish in marine water. Marine fishery resources include 7,500 KM of the Indian Coastline. 11. Mackerel Pomphret Tuna 12. Fishes harvested from saltwater regions. 13. Mariculture involves culturing of fish in marine water. Mariculture is a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, an enclosed section of the ocean. 14. Inland fisheries comprise fresh water & sea water where fish are trapped or captured. Fresh water resources include canals, ponds, reservoirs & rivers. Sea water resources include oceans. There is an overlap between bodies of water classified as coastal and bodies of water classified as estuaries. lagoons 15. The Composite fish farming system is a technology developed in India by the Indian Council of Agricultural Research in the 1970s. In this system both local and imported fish species, a combination of five or six fish species is used in a single fish pond. These species are selected so that they do not compete for food among them having different types of food habitats. As a result the food available in all the parts of the pond is used. Fish used in this system include catla and silver carp which are surface feeders, rohu a column feeder and mrigal and common carp which are bottom feeders. Other fish will also feed on the excreta of the common carp and this helps contribute to the efficiency of the system which in optimal conditions will produce 30006000 kg of fish per hectare per year. 16. Grass Carp Catlas Rohus Common Carp Mrigal Surface Feeders Middle-Zone Feeders Bottom Feeders Weed Feeders 17. These fishes can use all the food in the pond without fighting with each other. This increases the fish yield from the pond. 18. In intensive culture systems there is a decreased dependence on the availability of natural food and greater dependency on the use of commercial feeds. Densities of fish kept within such holding areas are limited by species tolerance, ability to grow at raised stocking densities and maintenance of environmental parameters rather than the production of a natural food supply. 19. Extensive aquaculture is the other form of fish farming. Extensive aquaculture is more basic than intensive aquaculture in that less effort is put into the husbandry of the fish. Extensive aquaculture is done in the ocean, natural and man-made lakes, bays, rivers, and Fiords. Fish are contained within these habitats by multiple mesh enclosures which also function as trapping nets during harvest. 20. One problem with such composite fish culture is that many of these fish breed only during monsoon. Even if fish seed is collected from the wild, it can be mixed with that of other species as well. So, a major problem in fish farming is the lack of availability of good- quality seed. To overcome this problem, ways have now been worked out to breed these fish in ponds using hormonal stimulation. Fishes are now injected with hormones that stimulate the production of eggs or seeds. This has ensured the supply of pure fish seed in desired quantities. 21. Q: How many types of fish farming are there? Name them. A: There are two types of fish farming: (a) Capture Fishing (b) Culture Fishing Q: How many types of fishing are there? Name them. A: There are two types of fishing: (a) Marine Fishing (b) Inland Fishing Q: Which types of fishes are these: (a) Prawn (b) Molluscs A: Shell Fishes 22. Q: Which fish feed at the surface of the sea? a) Rohus b) Grass Carp c) Catlas d) Common Carp Mrigal Q: Identify the diagram below: Estuaries