A fishing net or fishnet is a net that is used for fishing. 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.
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Cast nets are small round nets with weights on the edges which is thrown by the fisher. Sizes vary up to about four metres in 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.[1]
Coracle fishing is performed by two men, each seated in a coracle, plying his paddle with one hand and holding a shared net with the other. 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 secured.
The Chinese fishing nets (Cheena vala) are used at Kochi in India. They are an example of shore operated lift nets[2] because they are held horizontally by a large fixed structure and periodically lowered into the water. Huge mechanical contrivances hold out horizontal nets with diameters of twenty metres or more. The nets are dipped into the water and raised again, but otherwise cannot be moved.
This is a general term which can be applied to any net which is dragged or hauled across a river or along the bottom of a lake or sea.
The drift net is a net that is not anchored. It is usually a gillnet, and is commonly used in the coastal waters of many countries.[3] Its use on the high seas is prohibited, but still occurs.
A drive-in net is another fixed net, used by small-scale fishermen in some fisheries in Japan and South Asia, particularly in the Philippines. It is used to catch schooling forage fish such as fusiliers and other reef fish. It is a dustpan-shaped net, resembling a trawl net with long wings. The front part of the net is laid along the seabed. The fishermen either wait until a school swims into the net, or they drive fish into it by creating some sort of commotion. Then the net is closed by lifting the front end so the fish cannot escape.[4]
Fyke nets are bag-shaped nets which are held open by hoops. These can be linked together in long chains, and are used to catch eels in rivers. If fyke nets are equipped with wings and leaders, they can also be used in sheltered places in lakes where there is plenty plant life. Hundreds of these nets can be connected into systems where it is not practical to build large traps.[5]
The 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 marine life for many years.
Hand nets are held open by a hoop and are possibly on the end of a long stiff handle. They have been known since antiquity and may be used for sweeping up fish near the water surface like muskellunge and northern pike. When such a net is used by an angler to help land a fish it is known as a landing net.[6] In England, hand netting is the only legal way of catching eels and has been practised for thousands of years on the River Parrett and River Severn.
A special form of large hand net is the Lave net [7] now used in very few locations on the River Severn in England and Wales. The Lave net is set in the water and the fisherman waits till he feels a fish hit against the mesh and the net is then lifted. Fish as large as sturgeon are caught in lave nets.
A lift net has an opening which faces upwards. The net is first submerged to a desired depth, and then then lifted or hauled from the water. It can be lifted either manually or mechanically, and can be operated on a boat or from a shore.[8]
Research vessels collect plankton from the ocean using fine mesh plankton nets. The vessels either tow the nets through the sea or pump sea water onboard and then pass it through the net.[9]
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. In the UK seine netting for Salmon and Sea-trout in coastal waters is only permitted in a very few locations and where it is permitted one end of the seine must remain fixed and the other end is then waded out and returns to the fixed point. This variant is called Wade netting and is strictly controlled by law.[10]
A stake net is a form of net for catching salmon. It consists of a sheet of network stretched on stakes fixed into the ground, generally in rivers or where the sea ebbs and flows, for entangling and catching the fish.
A surrounding net surrounds fish on the sides and underneath. It is an evolution of the seine, and is typically used by commercial fishers.[11]
Tangle nets, also known as tooth nets, are similar to gillnets except they have a smaller mesh size designed to catch fish by the teeth or upper jaw bone instead of by the gills.[12]
A trammel is a fishing net with three layers of netting that is used to entangle fish or crustacea.[13] A slack central layer with a small mesh is sandwiched between two taut outer layers with a much larger mesh. The net is kept vertical by the floats on the headrope and weights on the bottomrope.
A trawl is a large net, conical in shape, designed to be towed in the sea or along the sea bottom. The trawl is pulled through the water by one or more boats, called trawlers or draggers. The activity of pulling the trawl through the water is called trawling or dragging.
Some types of fishing nets, like seine and trammel need to be kept hanging vertically in the water by means of floats at the top.
Between 177 and 180 the Greek author Oppian wrote the Halieutica, a didactic poem about fishing. He described various means of fishing including the use of nets cast from boats, scoop nets held open by a hoop, and various traps "which work while their masters sleep". Here is Oppian's description of fishing with a "motionless" net:
The fishers set up very light nets of buoyant flax and wheel in a circle round about while they violently strike the surface of the sea with their oars and make a din with sweeping blow of poles. At the flashing of the swift oars and the noise the fish bound in terror and rush into the bosom of the net which stands at rest, thinking it to be a shelter: foolish fishes which, frightened by a noise, enter the gates of doom. Then the fishers on either side hasten with the ropes to draw the net ashore.
Pictorial evidence of Roman fishing comes from mosaics which show nets.[15] In a parody of fishing, a type of gladiator called retiarius was armed with a trident and a casting-net. He would fight against the murmillo, who carried a short sword and a helmet with the image of a fish on the front.
In Norse mythology the sea giantess Rán uses a fishing net to trap lost sailors.
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