Fisheries Resources
As known, a fishery is renewable resources, which is available in the natur and also some view of them has already developed by human through culturing. Fisheries use natural resources and other resources as raw material on which the sector depends. Renewable resources include aquatic species, land and water. Other resources are artificialy generated, such as hatchery-produces seeds, feeds and fertilizers.
Fishery, which is relating to the natural resources are an integrated effort by humans to catch fish or other aquatic species. In this case, the activity is known as fishing. Generally, the fishery activity exists because of human need to get food or another purposed, such as sport or recreational fishing, or obtaining ornamental fish or fish products such as for oil fish. Industrial fisheries, for example, they do fisheries activities, but the catch that they are doing is not only for direct human consumption, but also for oil, medicin, powder and so on.
Fisheries resources are divided by two different resources, such as capture and aquaculture fisheries resources. Capture fisheries resources are usually considerated, used and managed on a stock-by-stock basis. There are impacted by fisher as well as other polluting and degrading economic activities. Meanwhile aquaculture resources comprise a wide variety of animal and plant species such as finfish, shrimp, prawns and crabs, clams, oysters and mussels as well as seaweeds and other aquatic plants for both use and productions.
Most of fisheries are marine resources, rather than freshwater resources and most of marine fisheries are based near to the coastal area, because fish are much more abundant near to the coastal shelf and in shallow water, due to in this area are much more aboundant the availability of nutrients. Sothat, most of harvesting activities (fishing) is much more operation in the coastal area and also because of harvesting in shallow waters is easier than in the open ocean (high sea). There are large and important fisheries worldwide for various species of fish, molluks and crustaceans. There are large and important fisheries worldwide for various species of fish, mollusks and crustaceans. However, a very small number of species support the majority of the world’s fisheries. Some of these species are herring, cod, anchovy, tuna, flounder, mullet, squid, shrimp, salmon, crab, lobster, oyster and scallops.
Fisheries are one of the important sources to provide world population’s protein and most of people living in the coastal area are heavily depending to the fisheries activities, especially in some developing countries. In this case, fisheries have been bigger and bigger business and help especially coastal communities to provide their own income. 60 procent people live near to the coastal areas and more than 80 procent of them do fisheries as their livelihood.
Fisheries industries are not only important source of their people’s income generation for developing countries, such as Peru, Indonesia, Chile, India, and Thailand. Developed countries, such as China, USA, Japan, Russia, and Norway are also providing their income from this sector. The total production from those countries, such as China, Peru, USA, Indonesia, Japan, Chile, India, Russia, Thailand and Norway accounted for more than half of the world's production.
According to data from Food and Agriculture Organization of the United Nations, in 2002 the global production from fishing and aquaculture reached about 133 million tonnes (FAO 2004). The top ten producer countries for marine and inland capture fisheries are China (16,6 Mio tonnes), Peru (8,8 Mio), USA (4,9 Mio), Indonesia (4,5 Mio), Japan (4,4 Mio), Chile (4,3 Mio), India (3,8 Mio), Russia (3,2 Mio), Thailand (2,9 Mio) and Norway (2,7 Mio).
Important issues and topics in fisheries
Considering the importance of fisheries, and that they depend on a natural resource, it is no surprise that there are many pressing environmental issues surrounding them. These can be classed into issues that involve the availability of fish to be caught, such as overfishing, sustainable fisheries, and fisheries management; and issues surrounding the impact of fishing on the environment, such as by-catch. These fishery conservation issues are generally considered part of marine conservation, and many of these issues are addressed in fisheries science programs.
They are also, however, controversial. There is an apparent and growing disparity between the availability of fish to be caught and humanity’s desire to catch them, a problem that is exacerbated by the rapidly growing world populations. As with some other environmental issues, often the people engaged in the activity of fishing – the fishers – and the scientist who study fisheries science, who are often acting as fishery managers, are in conflict with each other, as the dictates of economics mean that fishers have to keep fishing for their livelihood, but the dictates of sustainable sciences mean that some fisheries must close or reduce to protect the health of the population of the fish themselves. It is starting to be realized, however, that these two camps must work together to ensure fishery health through the 21st century and beyond.
Methods
Fishing techniques
Fishing methods vary according to the region, the species being fished for, and the amount of income and technology available to the fisher. A fishery can consist of one man with a small boat hand-casting nets, to a huge fleet of trawlers processing tons of fish per day. Some common commercial techniques today are trawling, seining, driftnetting, handlining, longlining, gillnetting and diving.
Fishing is the activity of hunting for fish. By extension, the term fishing is also applied to hunting for other aquatic animals such as various types of shellfish as well as squid, octopus, turtles, frogs and some edible marine invertebrates. The term fishing is not usually applied to the hunting of aquatic mammals such as whales. Fishing is an ancient and worldwide practice with various techniques and traditions and it has been transformed by modern technological developments. It has even became a sport of some account.
There are several traditinal techniques for fishing that has been used by human to get fish. Those techniques are:
(i) Hand fishing
With this technique, it is possible to fish with minimal equipment by using only the hands. In the USA catching catfish in this way is known as noodling. Divers can catch lobsters by hand. Pearl diving is the practice of hunting for oysters by free-diving to depths of up to 30 m. Hand-line fishing is a technique requiring a fishing line with a weight and one or more lure-like hooks.
(ii) Spear and bow fishing
Spear fishing is an ancient method of fishing and may be conducted with an ordinary spear. Traditional spear fishing is restricted to shallow waters, but the development of the speargun has made the method much more efficient. With practice, divers are able to hold their breath for up to four minutes and sometimes longer; of course, a diver with underwater breathing equipment can dive for much longer periods. Bow fishers use a bow and arrow to kill fish in shallow water from above.
(iii) Fishing nets
All fishing nets are meshes usually formed by knotting a relatively thin thread. Modern nets are usually made of artificial polyamides like nylon, although nets of organic polyamides such as wool or silk thread were common until recently and are still used in certain areas.
A small hand net held open by a hoop and possibly on the end of a long stiff handle has been known since antiquity and may be used for sweeping up fish near the water surface. Such a net used by an angler to aid in landing a captured fish is known as a landing net.
A casting net is circular with a weighted periphery. Sizes vary up to about 4 m diameter. The net is thrown by hand in such a manner that it spreads out on the water and sinks. Fish are caught as the net is hauled back in.
Coracle-fishing is performed by two men, each seated in his coracle and with one hand holding the net while, with the other, he plies his paddle. When a fish is caught, each hauls up his end of the net until the two coracles are brought to touch and the fish is then secured.
A seine is a large fishing net that may be arranged in a number of different ways. In purse seine fishing the net hangs vertically in the water by attaching weights along the bottom edge and floats along the top. A simple and commonly used fishing technique is beach seining, where the seine net is operated from the shore. Danish seine is a method which has some similarities with trawling.
Trawling is a method of fishing that involves actively pulling a fishing net through the water behind one or more boats.
A gillnet catches fish which try to pass through it by snagging on the gill covers. Thus trapped, the fish can neither advance through the net nor retreat.
Ghost nets are nets that have been lost at sea. They may continue to be a menace to wildlife for many years.
(iv) Dredging
There are types of dredges used for collecting scalops or oysters from the seabed. They tend to have the form of a scoop made of chain mesh and they are towed by a fishing boat. Scallop dredging is very destructive to the seabed, and nowadays is often replaced by mariculture or by scuba diving to collect the scallops.
(v) Fishing lines
Fish are caught with a fishing line by encouraging a fish to bite upon a fish hook or a gorge. A fishing hook will pierce the mouthparts of a fish and may be barbed to make escape less likely. A gorge is buried in the bait such that it would be swallowed end first. The tightening of the line would fix it cross-wise in the quarry's stomach or gullet and so the capture would be assured.
Fishing with a hook and line is called angling. In addition to the use of the hook and line used to catch a fish, a heavy fish may be landed by using a landing net or a hooked pole called a graff.
Trolling is a technique in which a fishing lure on a line is drawn through the water. Trolling from a moving boat is a technique of big-game fishing and is used when fishing from boats to catch large open-water species such as tuna and marlin. Trolling is also a freshwater angling technique most often used to catch trout. Trolling is also an effective way to catch northern pike in the great lakes. This technique allows anglers to cover a large body of water in a short time.
Long-line fishing is a commercial fishing technique that uses hundreds or even thousands of baited hooks hanging from a single line.
Snagging is a technique where the object is to hook the fish in the body. Generally, a large treble hook with a heavy sinker is cast into a river containing a large amount of fish, such as a Salmon, and is quickly jerked and reeled in. Due to the often illegal nature of this method some practitioners have added methods to disguise the practice, such as adding bait or reducing the jerking motion.
(vi) Kite fishing
Kite fishing is presumed to have been first invented in China. It was, and is, also used by the people of New Guinea and other Pacific Islands - either by cultural diffusion from China or independent invention.
Kites can provide the boatless fishermen access to waters that would otherwise be available only to boats. Similarly, for boat owners, kites provide a way to fish in areas where it is not safe to navigate such as shallows or coral reefs where fish may be plentiful. Kites can also be used for trolling a lure through the water.
Suitable kites may be of very simple construction. Those of Tobi Island are a large leaf stiffened by the ribs of the fronds of the coconut palm. The fishing line may be made from coconut fibre and the lure made from spiders webs.
Modern kitefishing is popular in New Zealand, where large delta kites of synthetic materials are used to fish from beaches, taking a line and hooks far out past the breakers.
(vii) Ice fishing
Ice fishing is the practice of catching fish with lines and hooks through an opening in the ice on a frozen body of water. It is practised by hunter-gatherers such as the Inuit and by anglers in other cold or continental climates.
(viii) Fish traps
Traps are culturally almost universal and seem to have been independently invented many times. There are essentially two types of trap, a permanent or semi-permanent structure placed in a river or tidal area and pot-traps that are baited to attract prey and periodically lifted.
(ix) Trained animals
This technique uses animal to help fishermen to fish. This technique used to be used by some fishermen in China and Japan for example. They trained cormorant to fish. Fishermen use the natural fish-hunting instincts of the cormorants to catch fish, but a metal ring placed round the bird's neck prevents large, valuable fish being swallowed. The fish are instead collected by the fisherman. The people of Nauru for other example used trained frigatebirds to fish on reefs.
(x) Toxins
Many hunter gatherer cultures use poisonous plants to stun fish so that they become easy to collect by hand. Some of these poisons paralyse the fish, others are thought to work by removing oxygen from the water.
Cyanides are used to capture live fish near coral reefs for the aquarium and seafood market. This illegal fishing occurs mainly in or near the Philippines, Indonesia, and the Caribbean to supply the 2 million marine aquarium owners in the world. Many fish caught in this fashion die either immediately or in shipping. Those that survive often die from shock or from massive digestive damage. The high concentrations of cyanide on reefs harvested in this fashion damages the coral polyps and has also resulted in cases of cyanide poisoning among local fishermen and their families.
(xi) Explosives
Dynamite or blast fishing, is done easily and cheaply with dynamite or homemade bombs made from locally available materials. Fish are killed by the shock from the blast and are then skimmed from the surface or collected from the bottom. The explosions indiscriminately kill large numbers of fish and other marine organisms in the vicinity and can damage or destroy the physical environment. Explosions are particularly harmful to coral reefs. Blast fishing is also illegal in many waterways around the world.
(xii) Electrofishing
A relatively new fishing technique is electrofishing, typically used for stream classification surveys and catching brood stock for hatcheries, or making estimates of populations in a body of water. A gated pulse of direct current is used to cause muscular contractions in a fish, called galvanotaxis, causing them to turn towards the source of the electrical current and swim towards it when correct pulse speeds and durations are used, along with correct current.
A low voltage or short pulse with long gaps will cause the fish to swim away from the device, and high voltage or long pulses with short rests can cause galvanonarcosis, or unconsciousness. Techniques for setting pulse length and patterns, current and voltage require great skill to fish effectively without killing or injuring fish if they are to be left unharmed. Dissolved minerals in the water can decrease resistance causing less of the current to pass through the fish, whereas fish recently entering fresh water from the ocean have high salinity and are more prone to electric shock. Also the smaller the fish, and consequently the less surface area in contact with the water, the higher the current required to produce galvanotaxis. Smaller fish also require shorter pulses, closer together, while large fish should have longer pulses at lower power and longer gaps between pulses.
Rigs can be battery powered back-packs or powered by a generator if they are mounted in a boat. They are typically equipped with a "dead-man switch" and a tilt switch to disable the device if the unit is tipped or the operator incapacitated. Protective equipment must be worn to isolate the operator and prevent electrocution.
Electro-fishing is also used to illegally catch Razorfish or Spoots, using a boat based generator. Current is passed into the sediment causing the Razorfish to 'jump' and be harvested by divers. For obvious reasons this method of electro-fishing is banned due to the risk to the divers.
Culture technique
Aquaculture methods also vary according to the types of culturing and also the amount of financial and technology available to the fish farmer. A fishery in this sub sector can of one man with a couple meter squares of ponds that cultured some spesific species of fish or more, to grow them and produce tons of fish per four or more months.
There are some methods related with aquaculture, such as seedling, breeding, hatchery, and growing. A few of technique for culturing fish are such as caging, pond, floating cage, aquarium, etc.
Fish processing
Ancient methods of preserving fish included drying, salting, pickling and smoking. All of these techniques are still used today but the more modern techniques of freezing and caning have taken on a large importance.
In the past, fishing vessels were restricted in range by the simple consideration that the catch must be returned to port before it spoils and becomes worthless. The development of refrigenation and freezing technologies transformed the commercial fishing industry: fishing vessels could be larger, spending more time away from port and therefore accessing fish stocks at a much greater distance.
Refrigeration and freezing also allow the catch to be distributed to markets further inland, reaching customers who previously would have had access only to dried or salted sea fish.
Fish products
Food
The flesh of many fish are primarily valued as a source of food; there are many edible species of fish as well as other sea food. Shellfish include shelled mollusc anc crustaceans used a food. Shelled molluscs include the clam, mussel, oyster, winkle and scallop, some crustaceans are shrimp, lobster, crayfish and crab.
Eggs, called roe, of various species may be eaten; roe comes from fish and certain marine invertebrates, such as sea urchins and shrimp. In some cultures, roe is considered a delicacy, for example caviar from the sturgeon. Squid and octopus are valued as food. Sea cucumber is considered a delicacy in Chinese cooking and is often served at New Year’s feasts, usually in soups. In some cultures, for example China, Japan, and Vietnam, certain species of jellyfish are consumed. Fish oil is valued as a dietary supplement.
Live fish
Live fish are collected for the international live food fish trade. Some seafood restaurants keep live fish in aquaria for display or for cultural beliefs. The majority of live fish kept at seafood restaurants, however, are desired for the freshness of the seafood, being killed only immediately before being cooked. Suiting customer preference, this practice makes the seafood higher in quality and better in taste. The prevalence of cultural beliefs and consumer standards helps to drive the demand for the live food fish trade.
Fish can also be collected in ways that do not injure them such as in a seine net or by placing an electric current into the water. Such techniques are used most often by researchers for observation and study but are also used by those who collect fish for the aquarium trade. There are several organizations devoted to improving the methods of collecting, handling, transporting, exporting and farming of wild and domesticated live food fish, as well as freshwater and marine tropical fish destined for aquaria.
4.3. Other products
Pearls and mother-of-pearl are valued for their lustre. Traditional methods of pearl hunting are now virtually extinct. Sharkskin and rayskin which are covered with, in effect, tiny teeth (dermal denticles) were used for the purposes that sandpaper currently is. These skins are also used to make leather. Sharkskin leather is used in the manufacture of hilts of traditional Japanese swords.
Sea horse, star fish, sea urchin and sea cucumber are used in traditional Chinese medicine. Tyrian purple is a pigment made from marine snails Murex brandaris and Murex trunculus. Sepia is a pigment made from the inky secretions of cuttlefish. Fish glue is made by boiling the skin, bones and swim bladders of fish. Fish glue has long been valued for its use in all manner of products from illuminated manuscript to the Mongoloan war bow. Isinglass is a substance obtained from the swim bladders of fish (especially sturgeon), it is used for the clarification of wine and beer. Fish emulsion is a fertilizer emulsion that is produced from the fluid remains of fish processed for fish oil and fish meal industrially.
Yudi Wahyudin, S.Pi., M.Si.
Direktur Institute for Applied Sustainable Development (IASD)
Jl. Bhayangkara I No.26, Sindangbarang, Bogor-16117, INDONESIA
Telp. 0062 251 8422735
Fax. 0062 251 8422735
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