Good morning class. Our lesson today is aquaculture methods and practices t8 quarter 2 lesson 324 week 4. Aquaculture Aquaculture has a tradition of about 4,000 years. It began in China possibly due to the desires of an emperor to have a constant supply of fish. It is speculated that the techniques for keeping fish in ponds originated in China with fishermen who kept their surplus catch alive temporarily in baskets submerged in rivers or small bodies of water created by damning one side of a riverbed. Another possibility is that aquaculture developed from ancient practices for trapping fish with the operations steadily improving from trapping holding to trapping holding growing and finally into complete husbandry practices. Ling 1977 overview of aquaculture methods and practices. A number of aquaculture practices are used worldwide in three types of environments. freshwater, brackish water and marine for a great variety of culture organisms. Freshwater aquaculture is carried out either in fish ponds, fish pens, fish cages or on a limited scale in rice patties. Brackish water aquaculture is done mainly in fish ponds located in coastal areas. Marine culture employs either fish cages or substrates for mollisks and seaweed such as stakes, ropes and rafts. These practices include one maraculture, two metahalian culture, three brackish water culture, four freshwater culture. Maraculture for the culture of fish, prawns and lobster floating cages are used. Racks, rafts, rope, pole and long lines are used for the culture of muscles, particularly pearl oyster. Seaweed also is widely cultured with the help of nets or webbings. Cage culture. It is an aquaculture production system made of a floating frame, net materials and mooring system with rope, buoy, anchor, etc. with a round or square shaped floating net to hold and culture large number of fishes and can be installed in reservoir, river, lake or sea. Cage culture involves the growing of fish in existing water resources. A catwalk and handrail is built around a battery of floating cages. Four types of cage culture. Fixed cages, submerged cages, floating cages, movable cages, raft culture is one of the commercially important methods of intensive aquaculture. These are the rectangular wooden frames floating on the water. They are made of bamboo and made to flows by empty dumps. The basic raft unit consists of a long floating rope void with numerous floats and anchored with fixed wood. Single floating rope raft. It is independently positioned raft units. They are not joined to other floating raft ropes but are anchored separately. Block of floating rafts is composed of between 10 to 40 floating kelp rope rafts joined together. Floating raft ropes in parallel series are positioned 3-5m apart so that water circulation is not impeded and so that kelp plants at maturity do not tangle. Rack culture is an improvement of intertidal culture methods over the traditional beach culture method. Using steel racks placed into the sand or mud bottom. Plastic mesh bags filled with small culture organisms are laid across the tops of the racks where they are surrounded with water when the tides come in. Rack and bag oyster culture. Pole culture is mainly undertaken in France. This is also called the bashau or steak culture. The poles used are big branches or trunks of oak tree for -6m in length which are staked in rows. 0.7 m apart on soft and muddy bottoms of the inner tidal zone during low tide. Long line culture is an alternative to raft culture in areas less protected from wave action. A long line supported by a series of small floats joined by a cable or chain and anchored at the bottom on both end is employed. Collected muscle spats on ropes or strings are suspended on the line. Bottom culture. Oysters have traditionally been cultured on the bottom just like a wild oyster. Bottom culture is placing the oyster on the bottom of the oyster lease or placing oyster shells on the bottom of the lease to catch wild oyster. Artificial reef culture are intentionally placed benthic structures built of natural or man-made materials which are designed to protect, enhance or restore components of marine ecosystem. Metahalene culture in offseason of salt manufacture the salt pans are utilized for fish culture. Culture of brine shrimp artia selena can be undertaken in these super saline salt pan salinity more than 200% area. The nopi of artia serves as a proteinrich live food for the thin fishes and shellfishes. The dormant eggs cysts of artia formed under unfavorable conditions also can earn good foreign exchange. Saltwater ponds can also be called marine ponds as they are filled with salt water like the sea and contain some of the same species. Salt marshes occur on the edge of saltwater ponds and in sheltered coastal locations like the heads of bays. They contain mostly coastal plants that are adapted to occasional flooding by seawater. Brackish water culture. It is rich in oxygen and plankton. Brackish water organisms can be cultured in various ways such as in tidal ponds, hens, cages or by rack, raft or rope culture. Mangrove crab, silicera are also cultured in the shallow brackish water. A. Bottom culture. B. Raft culture. C. Rat culture. D. Cage culture. Tidal ponds. A shallow coastal inlet or bay that fills and empties with water as the tide rises and falls. Often characterized by tidal flats and marshes. Pen culture. Pen culture generally refers to small enclosures used for the confinement or safekeeping of domestic animals. In aquaculture, it is defined as raising fish in a volume of water enclosed on all sides except the bottom permitting free circulation of water at least from one side. This system can be considered a hybrid between pond culture and cage culture. Freshwater culture. Freshwater culture refers to the raising and breeding of aquatic animals such as fish, shrimp, crab, and shellfish as well as aquatic plants for economic purposes. It uses ponds, reservoirs, lakes, rivers, and other inland waterways including brackish water, which play an important role in the aquaculture industry. Composite fish culture. Composite fish culture is a system in which five or six different species of fish are grown together in a single fish pond. Fish with different food habits are chosen so that they do not compete for food among themselves. This ensures complete utilization of food resources in the pond. Monosex culture. Monosex culture refers to the culture of either all male or all female populations. It is a sought-after approach in aquaculture because of its advantages. It also explores the mechanisms to achieve it based on different modes of sex determination and sexual differentiation. Moniecies culture. Moniecies culture focuses on culturing only one species of fish. Tilapia culture, for example, offers faster growth and prolific breeding when raised as a monoecies. Air breathing fish culture. Air breathing fish culture is practiced in shallow water bodies with poor oxygen content. Species such as chana, chloras, and heterobnus are commonly cultured in this system because of their ability to survive in low oxygen environments. Predator prey culture. Predator prey culture such as merl tilapia culture is undertaken in shallow waters and swampy areas. In this system, predator fish like moles are cultured along with their prey fish tilapia. [Music]