Fishing weir - WikiHQ

thumb|Weir-type [[fish trap]]

thumb|A tidal [[fish corral in Manila Bay, Philippines ()]]

A fishing weir, fish weir, fishgarth or kiddle is an obstruction placed in tidal waters, or wholly or partially across a river, to direct the passage of, or trap, fish. A weir may be used to trap marine fish in the intertidal zone as the tide recedes, fish such as salmon as they attempt to swim upstream to breed in a river, or eels as they migrate downstream. Alternatively, fish weirs can be used to channel fish to a particular location, such as to a fish ladder. Weirs were traditionally built from wood or stones. The use of fishing weirs as fish traps probably dates back prior to the emergence of modern humans, and have since been used by many societies around the world.

In the Philippines, specific indigenous fishing weirs (a version of the ancient Austronesian stone fish weirs) are also known in English as fish corrals and barrier nets.

Etymology

The English word 'weir' comes from the Anglo-Saxon wer, one meaning of which is a device to trap fish.

By region

Africa

A line of stones dating to the Acheulean in Kenya may have been a stone tidal weir in a prehistoric lake, which if true would make this technology older than modern humans.

Americas

North America

right|thumb|Salmon weir at Quamichan Village on the [[Cowichan River, Vancouver Island, c. 1866]]

thumb|right|[[Algonquian peoples|Algonquin fishing with weir and spears in a dugout canoe. After a drawing by colonist John White (1585).]]

In September 2014 researchers from University of Victoria investigated what may turn out to be a 14,000-year-old fish weir in of water off the coast of Haida Gwaii, British Columbia.

In Virginia, the Native Americans built V-shaped stone weirs in the Potomac River and James River. These were described in 1705 in The History and Present State of Virginia, In Four Parts by Robert Beverley Jr:

This practice was taken up by the early settlers but the Maryland General Assembly ordered the weirs to be destroyed on the Potomac in 1768. Between 1768 and 1828 considerable efforts were made to destroy fish weirs that were an obstruction to navigation and from the mid-1800s, those that were assumed to be detrimental to sports fishing.

South America

A large series of fish weirs, canals and artificial islands was built by an unknown pre-Columbian culture in the Baures region of Bolivia, part of the Llanos de Moxos. These earthworks cover over , and appear to have supported a large and dense population around 3000 BCE.

Stone fish weirs were in use 6,000 years ago in Chiloé Island off the coast of Chile.

Asia and Oceania

thumb|The [[Double-Heart of Stacked Stones fishing weir in Penghu, Taiwan]]

thumb|The ancient 'Ai'opio stone fish trap in [[Kaloko-Honokōhau National Historical Park|Honokohau, Hawaii]]

thumb|A fishing weir in [[Efate, Vanuatu]]

Tidal stone fish weirs are one of the ancestral fishing technologies of the seafaring Austronesian peoples. They are found on tidal estuaries and shallow coastal waters throughout regions settled by Austronesians during the Austronesian expansion (). They are known as or in Kyushu, in the Ryukyu Islands; , , , or in South Korea (particularly Jeju Island); and in Taiwan.

The Han Chinese also had separate ancient fish weir techniques, known as , which use bamboo gates or "curtains" in river estuaries. These date back to at least the 7th century in China.

Great Britain

In Great Britain the traditional form was one or more rock weirs constructed in tidal races or on a sandy beach, with a small gap that could be blocked by wattle fences when the tide turned to flow out again.

Wales

thumb|Remains of a medieval fish weir just above the low water mark at [[Lligwy Bay|Traeth Lligwy, Anglesey]]

thumb|upright=1.35|Gorad Gwyrfai fish weir near Caernarfon, Wales

Surviving examples, but no longer in use, can be seen in the Menai Strait, with the best preserved examples to be found at Ynys Gored Goch (Red Weir Island) dating back to around 1842. Also surviving are 'goredi' (originally twelve in number) on the beach at Aberarth, Ceredigion. Another ancient example was at Rhos Fynach in North Wales, which survived in use until World War I. The medieval fish weir at Traeth Lligwy, Moelfre, Anglesey was scheduled as an Ancient Monument in 2002.

England

Fish weirs were an obstacle to shipping and a threat to fish stocks, for which reasons over the course of history several attempts were made to control their proliferation. The Magna Carta of 1215 includes a clause embodying the barons' demands for the removal of the king's weirs and others:

A statute was passed during the reign of King Edward III (1327–1377) and was reaffirmed by King Edward IV in 1472 A further regulation was enacted under King Henry VIII, apparently at the instigation of Thomas Cromwell, when in 1535 commissioners were appointed in each county to oversee the "putting-down" of weirs. The words of the commission were as follows:

All weirs noisome to the passage of ships or boats to the hurt of passages or ways and causeys (i.e. causeways) shall be pulled down and those that be occasion of drowning of any lands or pastures by stopping of waters and also those that are the destruction of the increase of fish, by the discretion of the commissioners, so that if any of the before-mentioned depend or may grow by reason of the same weir then there is no redemption but to pull them down, although the same weirs have stood since 500 years before the Conquest.</blockquote>

The king did not exempt himself from the regulation and by the destruction of royal weirs lost 500 marks in annual income. The Lisle Papers provide a detailed contemporary narrative of the struggle of the owners of the weir at Umberleigh in Devon to be exempted from this 1535 regulation. The Salmon Fishery Act 1861 (24 & 25 Vict. c. 109) (relevant provisions re-enacted since) bans their use except wherever their almost continuous use can be traced to before the Magna Carta (1215).

Ireland

In Ireland, discoveries of fish traps associated with weirs have been dated to 8,000 years ago.

Gallery

File:Ålegård.gif|19th-century fishing weir used to trap eels on the Danish coast

File:Indian fish weir Smith River Henry County Virginia.JPG|The Martinsville Fish Dam Virginia, a historic Native American Indian fishing weir built with rocks

File:Fish trap Menai Strait.jpg|Remains of an ancient stone fishing weir in the tidal Menai Strait in Wales

File:澎湖石滬 1.jpg|Fishing weir, Penghu County

File:Yana.jpg|Fishing weir on the rapidly flowing Mogami River in Japan

File:Fishing at the falls Dem Rep Congo.jpg|Fishing weirs using baskets at a river waterfall, Democratic Republic of the Congo

File:Ancient Fishing Weir - geograph.org.uk - 637068.jpg|Ancient V-shaped fishing weir at Countisbury Cove, Somerset

File:Weervisserij Oosterschelde.jpg|Modern anchovy weir in the Oosterschelde near Bergen op Zoom in the Netherlands (aerial view)

</gallery>

References

External links

Prehistoric Fishweirs in Eastern North America – master's thesis on fish weirs