Technological evolution in fish catchingPresentation Transcript
FISHINGFishing is the activity of catching fish.It is an ancient practice dating back atleast 40,000 years. Since the 16thcentury fishing vessels have been ableto cross oceans in pursuit of fish andsince the 19th century it has beenpossible to use larger vessels and insome cases process the fish on board.Fish are normally caught in the wild.Techniques for catching fish includehand gathering, spearing, netting,angling and trapping.
STONE AGE FISH HOOK MADEFROM BONE
FAO STATISTICS According to FAO statistics, the total number of fishermen and fish farmers is estimated to be 38 million. Fisheries and aquaculture provide direct and indirect employment to over 500 million people. In 2005, the worldwide per capita consumption of fish captured from wild fisheries was 14.4 kilograms, with an additional 7.4 kilograms harvested from fish farms.
TECHNOLOGICAL EVOLUTION OFFISHING The ancient river Nile was full of fish; fresh and dried fish were a staple food for much of the population. The Egyptians invented various implements and methods for fishing and these are clearly illustrated in tomb scenes, drawings, and papyrus documents. Simple reed boats served for fishing. Woven nets, weir baskets made from willow branches, harpoons and hook and line (the hooks having a length of between eight millimetres and eighteen centimetres) were all being used. By the 12th dynasty, metal hooks with barbs were being used. Nile perch, catfish and eels were among the most important fish.
Fishing scenes are rarelyrepresented in ancient Greekculture, a reflection of the low socialstatus of fishing. They were usedfish-cage for keeping live fish or asa fish-trap. The Greek historianPolybius (ca 203 BC–120 BC), in hisHistories, describes hunting forswordfish by using a harpoon witha barbed and detachable head.
Roman fishing comes frommosaics which show fishingfrom boats with rod and lineas well as nets. Variousspecies such as conger,lobster, sea urchin, octopusand cuttlefish are illustrated.
In India, the Pandyas, a classicalDravidian Tamil kingdom, wereknown for the pearl fishery asearly as the 1st century BC. Theirseaport Tuticorin was known fordeep sea pearl fishing. Theparavas, a Tamil caste centred inTuticorin, developed a richcommunity because of their pearltrade, navigation knowledge andfisheries.
From ancient representations andliterature it is clear that fishing boatswere typically small, lacking a mastor sail, and were only used close tothe shore.In Norse mythology the seagiantess Rán uses a fishing net totrap lost sailors.The Moche people of ancientPeru depicted fisherman in theirceramics.
Crab fishing, 1891–1895. commercial fishermen in Alaska, early 20th century
EVIDENCE OF CHANGES REGARDINGGILL NET Gillnetting was an early fishing technology in Colonial America. Immigrant fishermen from northern Europe and the Mediterranean brought adaptation of the technology during 1860s. The fishermen used boat around 25‟(8mt.) long and powered by oars. Many of these boats also had small sails and were called “row-sail” boat. At the beginning of the 20th century steam powered ships would haul these small boat to their fishing ground and retrieve then at the end of each day. Gas powered boat were beginning to make their appearance and by 1930s the row-sail boat had virtually disappeared.
In 1931 the first powered drum was created and thisallowed the nets to be drawn in much faster andfishermen were able to fish in areas they had previouslybeen unable to go into.During World War II, navigation and communicationdevices, as well as many other forms of maritimeequipment (ex. depth-sounding and radar) wereimproved and made more compact. These devicesbecame much more accessible to the average fisherman.the fisherman were forced to invest more into theirboats and equipment in order to stay up to date withthe current technology.The introduction of fine synthetic fibres such as nylonin the construction of fishing gear during the 1960smarked an expansion in the commercial use of gillnets.
This type of net was heavily used by many Japanese,South Korean, and Taiwanese fishing fleets on the highseas in the 1980s to target tunas. Although highly selectivewith respect to size class of animals captured, gill nets areassociated with high numbers of incidental captures ofcetaceans, (whales and dolphins). In the Sri Lankan gill netfishery, one dolphin is caught for every 1.7-4.0 tonnes oftuna landed. This compares poorly with the rate of onedolphin per 70 tonnes of tuna landed in the eastern Pacificpurse seine tuna fishery. Gillnets were banned by theUnited Nations in 1993 in international waters, althoughtheir use is still permitted within 200 nautical miles(400 km) of a coast.
TRAWLING In the Middle Ages, Brixham was the largest fishing port in the South- West, and at one time it was the greatest in England. Brixham is also famous for being the town where the fishing trawler was invented in the 19th century. In the 1890s there were about 300 trawling vessels there, each owned by one man who was often the skipper of his own boat. The largest fishing port in Europe from the 1970s onwards has been Peterhead in the North-East corner of Scotland. In its prime in the 1980s Peterhead had over 500 trawlers staying at sea for a week each trip. Peterhead has seen a significant decline in the number of vessels and the value of fish landed has been reduced due to several decades of overfishing .
THE CHINESE AMERICANS The Chinese fishermen migrated to the California coast during 1850s. They explored a growing economy of the west coast of the US from Canada to Mexico. They used small boats to catch herring, soles and sharks. And for larger fishes like barracudas they used Chinese junks. Later the US law passed mainly Scott Act in 1888, established that the Chinese migrants, even when they had entered and were living the US legally, could not re- enter after having temporarily left US territory. The Chinese fishermen could not leave their boats the 3 mile zone of the west coast. It became unprofitable and they gave up fishing. The fishermen remained unchallenged only the area of shark fishing and salmon canaries.
TECHNOLOGICAL CHANGES IN CRAFTSRAFT:- A raft is any flat structure for support or transportation over water. It is the most basic of boat design, characterized by the absence of a hull. Rafts are usually kept float by using any combination of buoyant materials such as wood, sealed barrels or inflated air chambers.
CATAMARANS The catamarans are most primitive fishing craft of Kerala. Keel-less craft made of few logs of light wood. Logs are tied together at the two ends by coir ropes. 7.5 to 8.5 m length and 8 m width. It can accommodate three to four persons. Propelled manually with bamboo oars and sails.
DUG OUT CANOE Made by scooping out material from large trunk of tree(aini). Dug out canoes are of three types Larger one is Odam(11-13 m long) Medium one is Thonie(8-9 m long) Smaller one Bepputhonie(6-7 m long) Oldest boats found by archaeological excavation are dug out canoes dating back to the Neolithic Period around 7,000-8,000 years ago.
PLANK BUILT CANOE Constructed by seaming together planks. Seaming by using coil ropes copper nails. Larger ones called as Thanguvallom(11-13 m long) Smaller ones called Kochuvallom(6-7 m long)
DOGGER During 17th century the British developed the dogger, an early type of sailing trawler or long liner which commonly operated on the North Sea The dogger takes its name from the Dutch word dogger, meaning a fishing vessels which tows a trawl.
COMMERCIAL VESSELS In recent times, fishing boats are becoming more specialized and standardized Commercial fishing is a high risk industry, and countries are introducing regulations governing the constructing and operation of fishing vessels.
GLOBAL FISH PRODUCTION SCENARIO The production increased from 100.36 million tonnes in 1990 to 125.2 million tonnes in 1999. The production of fish in 2010 was 159 million tonnes. Fish catches accounted for 74% and aquaculture for 26% of the total harvest. China was the first to contribute overall production. India got the 4th place to the overall production.
GLOBAL CONSUMPTION OF FISH In 1998 fish supply reached an exceptional low due to El Nino and demand as well due to the financial crisis in emerging markets. The total food fish supply has been growing at a rate of 3.6% per annum since 1961. The world population increased 1.8% per annum. Per capita fish consumption increased from about 9 kg per annum to 16 kg in the recent decade. The consumption of fish in 2010 was 110 million tonnes.
HINDU DIETARY CUSTOMSGeneral Rules Tamas, Rajas and Sattva; - these Ayurvedic "vibrations" are characteristics of various foods and affect both the physical and astral bodies. This is the root theory behind various Hindu food customs. Tamasic (heavy) foods such as meat and fermented foods (including alcohol) promote dullness and inertia. Rajasic (expanding) foods including onions, garlic, hot spices, stimulants,FISHES, eggs and salt. are thought excite intellect and passion which interfere with meditation. Sattvic (ascending) foods including fruits, vegetables and grains are thought to promote transcendence, sublimity and orderliness. Higher caste people adhere to sattvic foods, middle casts indulge rajasic and lower castes are tamasic foods.
According to religious aspect fish is anunique food item to meet the nutritionaldemand for human population.From the economical view point theglobal demand of fish is increased rapidly.So, to meet the global demand aquacultureis necessary.
HISTORY OF FARMING The Neolithic culture and technology spread worldwide between 4,000 and 8,000 years ago. In China the „Sung Dynasty‟ started aquaculture. They were collected and store the fish only. It was around 500 BC. After this the „Ming Dynasty‟ started culture practice. They collected the fishes and also reared the fishes. Later „China Dynasty‟ came and they introduced the technologies of collection of fishes, rearing and fry production method.
TECHNOLOGICAL CHANGES ONAQUACULTUREEXTENSIVE AQUQCULTURE:- The growth rate of fish is limited. The available food is supplied from the nature. Additional fertilizer use to increase the photosynthetic production. Here aquaculturist choose a fiter algae feeder such as tilapia, a benthic feeder such as carp or catfish, zooplankton feeder various carps and submerged weed feeder grass carp.
INTENSIVE AQUACULTURE The amount of fish per unit surface area can be increased by providing sufficient oxygen, optimum water quality and best feeding schedule. The cost of inputs per unit of fish weight is higher than in extensive farming, especially because of the high cost of fish feed. Some producers have adapted their intensive systems in an effort to provide consumers with fish that do not carry dormant forms of viruses and diseases
CAGE CULTURE Fish cages are placed in lakes, ponds, rivers and oceans to contain and protect fish until they can be harvested. The methods are called „off-shore cultivation‟ when the cages are placed in the sea. The possibility of poaching and disease is less in cage culture and require minimum maintenance. In recent year the cage industry has made numerous technological advances in cage construction.
IRRIGATION DITCH OR PONDSYSTEM These use irrigation ditches or farm ponds to raise fish. In small systems the fish are often fed commercial fish food, and their waste products can help fertilize the fields. In larger ponds, the pond grows water plants and algae as fish food. Control of water quality is crucial. Yields can be low if the fish grow ill from electrolyte stress.
COMPOSITE FISH CULTURE The composite fish culture method is introduced in India in 1970 by the ICAR. A combination of five or six fish species is used in a single fish pond. Food available in all parts of 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. In optimal conditions will produce 3000–6000 kg of fish per hectare per year.
INTEGRATED RECYCLING SYSTEM The largest-scale pure fish farms use a system derived from the New Alchemy Institute in the 1970s. Basically, large plastic fish tanks are placed in a greenhouse. A hydroponic bed is placed near, above or between them. Tilapia is used as they eat the algae when the tank is properly fertilized. To maintain fishes in this method is very complicated so this method is not so common.
CLASSIC FRY FARMING This method is also known as „Flow through system‟. Trout and other sport fish are often raised from eggs to fry or fingerlings and then trucked to streams and released. Normally, the fry are raised in long, shallow concrete tanks, fed with fresh stream water. The fry receive commercial fish food in pellets.