A fishing fleet is an aggregate of commercial fishing vessels. The term may be used of all vessels operating out of a particular port, all vessels engaged in a particular type of fishing, or all fishing vessels of a country or region. Although fishing vessels are not formally organized as if they were a naval fleet often the constraints of time and weather are such that they must all leave or return together, thus creating at least the appearance of an organized body. Fishermen operating a particular type of vessel or in a particular port belong to a local association which disseminates information and may be used to coordinate activities, such as how best to prevent overfishing in particular areas. In 2002 the world fishing fleet numbered about four million vessels. About one-third were decked; the remaining undecked boats were less than 10 metres long, 65 percent were not fitted with mechanical propulsion systems. The FAO estimates; the average size of decked vessels is about 20 gross tons. Only one percent of the world fishing fleet is larger than 100 gross tons.
China has half of these larger vessels. There is no international instrument in force concerning the safety of fishing vessels. International conventions and agreements awaiting ratification which concern safety at sea are exclusively aimed at vessels 24 metres in length and over, therefore do not apply to artisan vessels in developing countries. Safety regulations for all fishing vessels are left entirely to national discretion; the fishing fleet was an ironic reference to the shipping of unmarried young women from the UK to India during the middle and latter years of the Raj, for the purposes of becoming married to colonial administrators and plantation supervisors. FAO: CWP Handbook of Fishery Statistical Standards: Section L: Fishery Fleet FAO: Fishing vessels
A Brixham trawler is a type of wooden, deep-sea fishing trawler first built in Brixham in Devon, England, in the 19th century and known for its high speed. The design was copied by boat builders around Britain, some were sold to fishermen in other countries on the North Sea; the Brixham trawler was a heavy displacement boat of some 60–80 ft length on the deck, with a long straight keel, a straight vertical stem a fantail stern, a low freeboard to ease the handling of the nets, though this feature was disguised by high bulwarks. Brixham trawlers carried a tall gaff rig ketch rigged though simply a large sloop, powerful enough to carry them to and from the fishing grounds and to tow large trawls. Renowned yacht aerodynamicist and sailor C. A. Marchaj commented on the type, "With little area of keel surface, these boats lacked weatherliness as compared with the Quay Punt… Not without reason, fishermen of the north-east coast swore that the forefoot took them to windward."Brixham once had a fleet of 400 such vessels, whose distinctive red sails were coated with local red ochre for protection.
Other fleets were at Lowestoft with 375 trawlers, 450 at Hull, 625 at Great Yarmouth and 840 at Grimsby, with smaller numbers at other places. Only five remain afloat. One of them, took part in the Thames Diamond Jubilee Pageant. On 1 January 1915 the crew of Provident BM291 rescued 71 sailors from HMS Formidable and sunk by a German submarine in the English Channel during the night in a gale. Register of Brixham trawlers
Longline fishing, or longlining, is a commercial fishing technique. It uses a long line, called the main line, with baited hooks attached at intervals by means of branch lines called snoods. A snood is a short length of line, attached to the main line using a clip or swivel, with the hook at the other end. Longlines are classified by where they are placed in the water column; this can be at the bottom. Lines can be set by means of an anchor, or left to drift. Hundreds or thousands of baited hooks can hang from a single line. Longliners – fishing vessels rigged for longlining – target swordfish, halibut and many other species. In some unstable fisheries, such as the Patagonian toothfish, fishermen may be limited to as few as 25 hooks per line. In contrast, commercial longliners in certain robust fisheries of the Bering Sea and North Pacific run over 2,500 hand-baited hooks on a single series of connected lines many miles in length. Longlines can be set to hang near the surface to catch fish such as tuna and swordfish or along the sea floor for groundfish such as halibut or cod.
Longliners fishing for sablefish referred to as black cod set gear on the sea floor at depths exceeding 1,100 metres using simple equipment. Longlines with traps attached. Longline fishing is prone to the incidental catching and killing of dolphins, sea turtles, sharks, but can be more ecologically sustainable than some other commercially significant harvesting methods. Longline fishing is controversial in some areas because of bycatch, fish caught while seeking another species or immature juveniles of the target species; this can cause many issues, such as the killing of many other marine animals while seeking certain commercial fish. Seabirds can be vulnerable during the setting of the line. Methods to mitigate incidental mortality have succeeded in some fisheries. Mitigation techniques include the use of weights to ensure the lines sink the deployment of streamer lines to scare away birds, setting lines only at night in low light, limiting fishing seasons to the southern winter, not discharging offal while setting lines.
The Hawaii-based longline fishery for swordfish was closed in 2000 over concerns of excessive sea turtle by-catch loggerhead sea turtles and leatherback turtles. Changes to the management rules allowed the fishery to reopen in 2004. Gear modification a change to large circle-hooks and mackerel-type baits, eliminated much of the sea turtle by-catch associated with the fishing technique, it has been claimed that one consequence of the closure was that 70 Hawaii-based vessels were replaced by 1,500-1,700 longline vessels from various Asian nations, but this is not based on any reliable data. Due to poor and non-existent catch documentation by these vessels, the number of sea turtles and albatross caught by these vessels between 2000 and 2004 will never be known. Hawaii longline fishing for swordfish closed again on 17 March 2006, when the by-catch limit of 17 loggerhead turtles was reached. In 2010 the by-catch limit for loggerhead turtles was raised, but was restored to the former limit as a result of litigation.
The Hawaii-based longline fisheries for tuna and swordfish are managed under sets of different rules. The tuna fishery is one of the best managed fisheries in the world, according to the UN Code of Responsible Fishing, but has been criticized by others as being responsible for continuing by-catch of false killer whales and other nontargeted wildlife, as well as placing pressure on depleted bigeye tuna stocks. Commercial longline fishing is one of the main threats to albatrosses. Of the 22 albatross species recognized in the IUCN Red List, six are threatened, nine are vulnerable; the IUCN lists three species as critically endangered: the Amsterdam albatross, the Tristan albatross and the waved albatross. The remaining four are near threatened. Albatrosses and other seabirds which feed on offal are attracted to the set bait, become hooked on the lines and drown. An estimated 8,000 albatross per year are killed in this way. In the US, a study found that the risk for non-fatal injuries was 35 per 1,000 full-time equivalent employees, about three times higher than average U.
S. worker.. This article incorporates public domain material from the National Institute for Occupational Safety and Health document "Fleet Safety Fact Sheet: Freezer Longliners". Brothers, N P. Rome, FAO Fisheries Circular No 937. Eigaard B, Thomsen H, Hovgaard H, Nielsen A and Rijnsdorpd AD "Fishing power increases from technological development in the Faroe Islands longline fishery" Canadian Journal of Fisheries and Aquatic Sciences, 69: 1970–1982. Doi:10.1139/f2011-103 FAO Technical Guidelines for Responsible Fisheries, Number 1: Fishing operations, supplement 2 Best practices to reduce incidental catch of seabirds in capture fisheries Rome. ISBN 978-92-5-106423-8. Gabriel, Otto. Fish catching methods of the world. Blackwell. ISBN 978-0852382806. George JP Longline fishing Volume 22 of FAO Training Series, FAO, Rome. ISBN 9789251030783. Jhonson, Duglas H. S. Geological Survey. Valdemarsen, John W Incidental catch of seabirds in longline fisheries UN Atlas of the Oceans
Southeast Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China and Japan, east of India, west of Papua New Guinea, north of Australia. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, to the south by Australia and the Indian Ocean; the region is the only part of Asia that lies within the Southern Hemisphere, although the majority of it is in the Northern Hemisphere. In contemporary definition, Southeast Asia consists of two geographic regions: Mainland Southeast Asia known as Indochina, comprising parts of Northeast India, Laos, Thailand and West Malaysia. Maritime Southeast Asia known as Nusantara, the East Indies and Malay Archipelago, comprises the Andaman and Nicobar Islands of India, East Malaysia, the Philippines, East Timor, Christmas Island, the Cocos Islands. Taiwan is included in this grouping by many anthropologists; the region lies near the intersection of geological plates, with both heavy seismic and volcanic activities.
The Sunda Plate is the main plate of the region, featuring all Southeast Asian countries except Myanmar, northern Thailand, northern Laos, northern Vietnam, northern Luzon of the Philippines. The mountain ranges in Myanmar and peninsular Malaysia are part of the Alpide belt, while the islands of the Philippines are part of the Pacific Ring of Fire. Both seismic belts meet in Indonesia, causing the region to have high occurrences of earthquakes and volcanic eruptions. Southeast Asia covers about 4.5 million km2, 10.5% of Asia or 3% of earth's total land area. Its total population is about 8.5 % of the world's population. It is the third most populous geographical region in the world after East Asia; the region is culturally and ethnically diverse, with hundreds of languages spoken by different ethnic groups. Ten countries in the region are members of ASEAN, a regional organization established for economic, military and cultural integration amongst its members; the region, together with part of South Asia, was well known by Europeans as the East Indies or the Indies until the 20th century.
Chinese sources referred the region as 南洋, which means the "Southern Ocean." The mainland section of Southeast Asia was referred to as Indochina by European geographers due to its location between China and the Indian subcontinent and its having cultural influences from both neighboring regions. In the 20th century, the term became more restricted to territories of the former French Indochina; the maritime section of Southeast Asia is known as the Malay Archipelago, a term derived from the European concept of a Malay race. Another term for Maritime Southeast Asia is Insulindia, used to describe the region between Indochina and Australasia; the term "Southeast Asia" was first used in 1839 by American pastor Howard Malcolm in his book Travels in South-Eastern Asia. Malcolm only included the Mainland section and excluded the Maritime section in his definition of Southeast Asia; the term was used in the midst of World War II by the Allies, through the formation of South East Asia Command in 1943.
SEAC popularised the use of the term "Southeast Asia," although what constituted Southeast Asia was not fixed. However, by the late 1970s, a standard usage of the term "Southeast Asia" and the territories it encompasses had emerged. Although from a cultural or linguistic perspective the definitions of "Southeast Asia" may vary, the most common definitions nowadays include the area represented by the countries listed below. Ten of the eleven states of Southeast Asia are members of the Association of Southeast Asian Nations, while East Timor is an observer state. Papua New Guinea has stated that it might join ASEAN, is an observer. Sovereignty issues exist over some territories in the South China Sea; some southern parts of Mainland China, as well as Hong Kong and Taiwan, are considered as part of Southeast Asia by some authors. * Administrative centre in Putrajaya. Southeast Asia is geographically divided into two subregions, namely Mainland Southeast Asia and Maritime Southeast Asia. Mainland Southeast Asia includes: Maritime Southeast Asia includes: The Andaman and Nicobar Islands of India are geographically considered part of Maritime Southeast Asia.
Eastern Bangladesh and Northeast India have strong cultural ties with Southeast Asia and sometimes considered both South Asian and Southeast Asian. Sri Lanka has on some occasions been considered a part of Southeast Asia because of its cultural ties to mainland Southeast Asia; the rest of the island of New Guinea, not part of Indonesia, Papua New Guinea, is sometimes included, so are Palau and the Northern Mariana Islands, which were all part of the Spanish East Indies with strong cultural and linguistic ties to the region the Philippines. The eastern half of Indonesia and East Timor are considered to be biogeographically part of Oceania due to its distinctive faunal features. New Guinea and its surrounding islands are geologically considered as a part of Australian continent, connected via the Sahul Shelf; the region
Seine fishing is a method of fishing that employs a fishing net called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be deployed from the shore from a boat. Boats deploying seine nets are known as seiners. Two main types of seine net are deployed from seiners: Danish seines; the word seine has its origins in the Old English segne, which entered the language via Latin sagena, from the original Greek σαγήνη sagēnē. Seines have been used in the past, including by stone age societies. For example, the Māori used large canoes to deploy seine nets; the nets were woven from green flax, with stone weights and light wood or gourd floats, could require hundreds of men to haul. Native Americans on the Columbia River wove seine nets from spruce root fibers or wild grass, again using stones as weights. For floats they used sticks made of cedar which moved in a way which frightened the fish and helped keep them together.
Seine nets are well documented in ancient cultures in the Mediterranean region. They appear in Egyptian tomb paintings from 3000 BC. In ancient Roman literature, the poet Ovid makes many references to seine nets, including the use of cork floats and lead weights. A common type of seine is a purse seine, named such because along the bottom. A line passes through all the rings, when pulled, draws the rings close to one another, preventing the fish from "sounding", or swimming down to escape the net; this operation is similar to a traditional style purse. The purse seine is a preferred technique for capturing fish species which school, or aggregate, close to the surface: sardines, anchovies and certain species of tuna. Boats equipped with purse seines are called purse seiners. Purse seine fishing can be a sustainable way of fishing, as it can result in smaller amounts of by-catch when used to catch large species of fish that shoal together; when used to catch fish that shoal together with other species, or when used in parallel with fish aggregating devices, the percentage of by-catch increases.
Use of purse seines is regulated by many countries. In Sri Lanka, using this type of net within 7 kilometers of the shore is illegal. However, they can be used after obtaining permission from authorities. Purse seine fishing can have negative impacts on fish stocks because it can involve the bycatch of non-target species and it can put too much pressure on fish stocks; the power block is a mechanized pulley used on some seiners to haul in the nets. According to the UN Food and Agriculture Organization, no single invention has contributed more to the success of purse seine net hauling than the power block; the Puretic power block line was introduced in the 1950s and was the key factor in the mechanization of purse seining. The combination of these blocks with advances in fluid hydraulics and the new large synthetic nets changed the character of purse seine fishing; the original Puretic power block was driven by an endless rope from the warping head of a winch. Nowadays, power blocks are driven by hydraulic pumps powered by the main or auxiliary engine.
Their rpm and direction can be controlled remotely. A minimum of three people are required for power block seining. In many operations a fourth person stacks the leadline, a fifth person stacks the web. In certain parts of the western United States as well as Canada on the coast of British Columbia, drum seining is a method of seine fishing, adopted in the late 1950s and is now used in that region; the drum seine uses a horizontally mounted drum to store the net instead of a power block. The net is pulled in over a roller, which spans the stern, passes through a spooling gear with upright rollers; the spooling gear is moved from side to side across the stern which allows the net to be guided and wound on the drum. There are several advantages to the drum seine over the power block; the net can be hauled quickly - at more than twice the speed of using a power block, the net does not require overhead handling, the process is therefore safer. The most important advantage is. However, it is illegal to use a seine drum in the state of Alaska.
A Danish seine occasionally called an anchor seine, consists of a conical net with two long wings with a bag where the fish collect. Drag lines extend from the wings, are long so they can surround an area. A Danish seine is similar to a small trawl net, but the wire warps are much longer and there are no otter boards; the seine boat drags the net in a circle around the fish. The motion of the warps herds the fish into the central net. Danish seiner vessels are larger than purse seiners, though they are accompanied by a smaller vessel; the drag lines are stored on drums or coiled onto the deck by a coiling machine. A brightly coloured buoy, anchored as a "marker", serves as a fixed point. A power block mounted on a boom or a slewing deck crane, hauls the seine net. Danish seining works best on demersal fish which are either scattered on or close to the bottom of the sea, or are aggregated, they are used when there are rough seabeds which are not trawlable. It is useful in northern regions, b
Scuba diving is a mode of underwater diving where the diver uses a self-contained underwater breathing apparatus, independent of surface supply, to breathe underwater. Scuba divers carry their own source of breathing gas compressed air, allowing them greater independence and freedom of movement than surface-supplied divers, longer underwater endurance than breath-hold divers. Although the use of compressed air is common, a new mixture called enriched air has been gaining popularity due to its benefit of reduced nitrogen intake during repetitive dives. Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled, consist of one or more diving cylinders containing breathing gas at high pressure, supplied to the diver through a regulator, they may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases; the volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration.
Rebreathers extend. Scuba diving may be done recreationally or professionally in a number of applications, including scientific and public safety roles, but most commercial diving uses surface-supplied diving equipment when this is practicable. Scuba divers engaged in armed forces covert operations may be referred to as frogmen, combat divers or attack swimmers. A scuba diver moves underwater by using fins attached to the feet, but external propulsion can be provided by a diver propulsion vehicle, or a sled pulled from the surface. Other equipment includes a mask to improve underwater vision, exposure protection, equipment to control buoyancy, equipment related to the specific circumstances and purpose of the dive; some scuba divers use a snorkel. Scuba divers are trained in the procedures and skills appropriate to their level of certification by instructors affiliated to the diver certification organisations which issue these certifications; these include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment, emergency procedures for self-help and assistance of a equipped diver experiencing problems.
A minimum level of fitness and health is required by most training organisations, but a higher level of fitness may be appropriate for some applications. The history of scuba diving is linked with the history of scuba equipment. By the turn of the twentieth century, two basic architectures for underwater breathing apparatus had been pioneered. Closed circuit equipment was more adapted to scuba in the absence of reliable and economical high pressure gas storage vessels. By the mid twentieth century, high pressure cylinders were available and two systems for scuba had emerged: open-circuit scuba where the diver's exhaled breath is vented directly into the water, closed-circuit scuba where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated. Oxygen rebreathers are depth-limited due to oxygen toxicity risk, which increases with depth, the available systems for mixed gas rebreathers were bulky and designed for use with diving helmets; the first commercially practical scuba rebreather was designed and built by the diving engineer Henry Fleuss in 1878, while working for Siebe Gorman in London.
His self contained breathing apparatus consisted of a rubber mask connected to a breathing bag, with an estimated 50–60% oxygen supplied from a copper tank and carbon dioxide scrubbed by passing it through a bundle of rope yarn soaked in a solution of caustic potash, the system giving a dive duration of up to about three hours. This apparatus had no way of measuring the gas composition during use. During the 1930s and all through World War II, the British and Germans developed and extensively used oxygen rebreathers to equip the first frogmen; the British adapted the Davis Submerged Escape Apparatus and the Germans adapted the Dräger submarine escape rebreathers, for their frogmen during the war. In the U. S. Major Christian J. Lambertsen invented an underwater free-swimming oxygen rebreather in 1939, accepted by the Office of Strategic Services. In 1952 he patented a modification of his apparatus, this time named SCUBA, which became the generic English word for autonomous breathing equipment for diving, for the activity using the equipment.
After World War II, military frogmen continued to use rebreathers since they do not make bubbles which would give away the presence of the divers. The high percentage of oxygen used by these early rebreather systems limited the depth at which they could be used due to the risk of convulsions caused by acute oxygen toxicity. Although a working demand regulator system had been invented in 1864 by Auguste Denayrouze and Benoît Rouquayrol, the first open-circuit scuba system developed in 1925 by Yves Le Prieur in France was a manually adjusted free-flow system with a low endurance, which limited its practical usefulness. In 1942, during th
Boat building is the design and construction of boats and their systems. This includes at a minimum a hull, with propulsion, navigation and other systems as a craft requires. Wood is the traditional boat building material used for spar construction, it is buoyant available and worked. It is a popular material for small boats, its abrasion resistance varies according to the hardness and density of the wood and it can deteriorate if fresh water or marine organisms are allowed to penetrate the wood. Woods such as Teak and some cedars have natural chemicals which prevent rot whereas other woods, such as Pinus radiata, will rot quickly; the hull of a wooden boat consists of planking fastened to frames and a keel. Keel and frames are traditionally made of hardwoods such as oak while planking can be oak but is more softwood such as pine, larch or cedar. Plywood is popular for amateur construction but only marine ply using waterproof glues and laminates should be used. Cheap construction plywood has voids in the interior layers and is not suitable to boat building as the voids trap moisture and accelerate rot as well as physically weaken the plywood.
No plywood should be coated with epoxy resin and/or a good paint system. Varnish and Linseed oil should not be used on the exterior of a hull for waterproofing. Varnish has about 60% of the water resistance of a good paint system. Only boiled linseed oil should be used on a boat and only in the interior as it has little water resistance but it is easy to apply and has a pleasant smell. Note that used linseed rags should not be left in a pile as they can catch fire. A valuable 200-year-old waka caught fire in New Zealand in June 2014 when restorers left rags piled overnight. Raw linseed oil is not suited to boats as it stays oily for a long time. Mildew will grow well on raw linseed oil treated timber but not on boiled linseed oil. More introduced tropical woods as mahogany, okoumé, Keruing, azobé and merbau. are used. With tropical species, extra attention needs to be taken to ensure that the wood is indeed FSC-certified. Teak or iroko is used to create the deck and any superstructure. Glue, rivets and/or nails are used to join the wooden components.
Before teak is glued the natural oil must be wiped off with a chemical cleaner, otherwise the joint will fail. Some types of wood construction include: Carvel, in which a smooth hull is formed by edge joined planks attached to a frame; the planks may be curved in cross section like barrel staves. Carvel planks are caulked with oakum or cotton, driven into the seams between the planks and covered with some waterproof substance, it is believed to have originated in the Mediterranean. A number of boat building texts are available. Clinker is a technique identified with the Scandinavians and Ingveonic people in which wooden planks are fixed to each other with a slight overlap, beveled for a tight fit; the planks may be mechanically connected to each other with copper rivets, bent over iron nails, screws or in modern boats with adhesives. Steam bent wooden ribs are fitted inside the hull. Strip planking is yet another type of wooden boat construction similar to carvel, it is a glued construction method, popular with amateur boatbuilders as it is quick, avoids complex temporary jig work and does not require shaping of the planks.
Sheet plywood boat building uses sheets of plywood panels fixed to longitudinal long wood such the chines, inwhales or intermediate stringers which are all bent around a series of frames. By attaching the ply sheets to the longwood rather than directly to the frames this avoids hard spots or an unfair hull. Plywood may be used in single sheets; these hulls have one or more chines and the method is called Ply on Frame construction. A subdivision of the sheet plywood boat building method is known as the stitch-and-glue method, where pre-shaped panels of plywood are drawn together edge glued and reinforced with fibreglass without the use of a frame. Metal or plastic ties, nylon fishing line or copper wires pull curved flat panels into three-dimensional curved shapes; these hulls have one or more chines. Marine grade plywood of good quality is designated "WBP" or more BS 1088. Australian plywood manufacturers and suppliers have issued warnings that some Asian nations are selling ply stamped BS 1088 which does not meet international standards.
They say outer plies are too thin or are thin or high-grade surface ply such as Okoume is combined with a much heavier and wider inner cores. Most high-grade marine Okoume ply uses lightweight poplar inner cores; the 1088 stamp is blurred in the poor Asian ply so it is not clear. In Australia and New Zealand a higher-grade marine ply than BS1088 is AS2272, it requires. The most common plywood used for this grade is plantation-grown Hoop Pine, fine grained smooth, moderately light. Hoop pine has a high stress rating of F17, indicating high strength. Meranti ply has a stress rating of F14 and Okoume ply F8. Okoume ply is coated with epoxy to increase strength and impact resistance as well as to exclude water. B