Gill net

Gillnetting is a common fishing method used by commercial and artisanal fishermen of all the oceans and in some freshwater and estuary areas. “Gill nets are vertical panels of netting normally set in a straight line. Fish may be caught by gill nets in 3 ways :

Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free itself, the twine slips behind the gill cover and prevents escape.”

Gillnets are so effective that their use is closely monitored and regulated by fisheries management and enforcement agencies. Mesh size, twine strength, as well as net length and depth are all closely regulated to reduce bycatch of non-target species. Gillnets have a high degree of size selectivity. Most salmon fisheries in particular have an extremely low incidence of catching non-target species.

Gillnets existed in ancient times as archaeological evidence from the Middle East demonstrates. In North America, Native American fishermen used cedar canoes and natural fibre nets, e.g., made with nettles or the inner bark of cedar. They would attach stones to the bottom of the nets as weights, and pieces of wood to the top, to use as floats. This allowed the net to suspend straight up and down in the water. Each net would be suspended either from shore or between two boats. Native fishers in the Pacific Northwest, Canada, and Alaska still commonly use gillnets in their fisheries for salmon and steelhead.

Both drift gillnets and setnets have long been used by cultures around the world. There is evidence of fisheries exploitation, including gillnetting, going far back in Japanese history, with many specific details available from the Edo period (1603–1868). Fisheries in the Shetland Islands, which were settled by Norsemen during the Viking age, share cultural and technological similarities with Norwegian fisheries, including gillnet fisheries for herring. Many of the Norwegian immigrant fishermen who came to fish in the great Columbia River salmon fishery during the second half of the 19th century did so because they had experience in the gillnet fishery for cod in the waters surrounding the Lofoten Islands of northern Norway. Gillnets were used as part of the seasonal round by Swedish fishermen as well. Welsh and English fishermen gillnetted for Atlantic salmon in the rivers of Wales and England in coracles, using hand-made nets, for at least several centuries. These are but a few of the examples of historic gillnet fisheries around the world.

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Wikipedia