Friday, November 2, 2007

Fishing nets

From Wikipedia, the free encyclopedia

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.

Dredging

From Wikipedia, the free encyclopedia

There are types of dredges used for collecting scallops or oysters from the seabed. They tend to have the form of a scoop made of chain mesh called dredges and they are towed by a fishing boat. Scallop dredging is very destructive to the seabed, because the marine life is unable to survive the weight of the dredge. This is extremely detrimental to coral bed since they take centuries to rebuild themselves. Dredging could be compared to unmonitored forest clearing, where it can wipe out an ecosystem. Nowadays, this method of fishing is often replaced by mariculture or by scuba diving to collect the scallops.

Fishing lines

From Wikipedia, the free encyclopedia

Fishing line is any cord made for fishing. Important parameters of a fishing line are its length, material, and weight (thicker, sturdier lines are more visible to fish). Factors that may determine what line an angler chooses for a given fishing environment include breaking strength, knot strength, UV resistance, castability, limpness, stretch, abrasion resistance, and visibility.

Kite fishing

From Wikipedia, the free encyclopedia

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.[11]

Modern kitefishing is popular in New Zealand, where large delta kites of synthetic materials are used to fish from beaches[12], taking a line and hooks far out past the breakers. Kite fishing is also emerging in Melbourne where sled kites are becoming popular, both off beaches and off boats and in freshwater areas. The disabled community are increasingly using the kites for fishing as they allow mobility impaired people to cast the bait further out than they would otherwise be able to.

Ice fishing

From Wikipedia, the free encyclopedia

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.

Fish traps / Trap Nets

From Wikipedia, the free encyclopedia

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.

Indigenous Australians were, prior to European colonisation, most populous in Australia's better-watered areas such as the Murray-Darling river system of the south-east. Here, where water levels fluctuate seasonally, indigenous people constructed ingenious stone fish traps. Unfortunately, most have been completely or partially destroyed. The largest and best known were the Brewarrina fish traps on the Barwon River at Brewarrina in New South Wales, which fortunately are at least partly preserved. The Brewarinna fish traps caught huge numbers of migratory native fish as the Barwon River rose in flood and then fell. In southern Victoria, indigenous people created an elaborate systems of canals, some more than 2 km long. The purpose of these canals was the encouragement and catching of eels, a fish of short coastal rivers (as opposed to rivers of the Murray-Darling system). The eels were caught by a variety of traps including stone walls constructed across canals with a net placed across an opening in the wall. Traps at different levels in the marsh came into operation as the water level rose and fell. Somewhat similar stone wall traps were constructed by native American Pit River people in north-eastern California.

A technique called dam fishing is used by the Baka pygmies. This involves the construction of a temporary dam resulting in a drop in the water levels downstream -- allowing fish to be easily collected.

In medieval Europe, large fishing weir structures were constructed from wood posts and wattle fences. 'V' shaped structures in rivers could be as long as 60 m and worked by directing fish towards fish traps or nets. Such fish traps were evidently controversial in medieval England. The Magna Carta includes a clause requiring that they be removed:

All fish-weirs shall be removed from the Thames, the Medway, and throughout the whole of England, except on the sea coast.

Basket weir fish traps were widely used in ancient times. They are shown in medieval illustrations and surviving examples have been found. Basket weirs are about 2 m long and comprise two wicker cones, one inside the other -- easy to get into and hard to get out.

Fishing method of Wagenya people in Congo.

From Wikipedia, the free encyclopedia

The Wagenya people, in the Democratic Republic of Congo, build a huge system of wooden tripods across the river. These tripods are anchored on the holes naturally carved in the rock by the water current. To these tripods are anchored large baskets, which are lowered in the rapids to "sieve" the waters for fish. It is a very selective fishing, as these baskets are quite big and only large size fish are trapped. Twice a day the adults Wagenya people pull out these baskets to check whether there are any fish caught; in which case somebody will dive into the river to fetch it.

In the Great Lakes Region of the United States of America, Fishermen submerse a long, visible mesh wall running perpendicular to the shoreline that guides fish (who instinctively swim towards deeper water when coming upon a large obstacle) into a maze that ends in a large mesh "pot", that can be raised up to the boat to haul the fish in. This method of fishing results in fish staying alive until the time they are hauled into the boat, versus being entangled and killed in a gill net. This method also allows for sportfish and other protected species to be released without harm.

No comments: