Fishing weir

A fishing weir is an ancient type of fish trap that is traceable back to Roman times in the UK. It is also a technology used by, among others, North American Natives and early settlers to catch fish for trade and to feed their communities.

History

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." [ [http://www.fordham.edu/halsall/source/magnacarta.html The Text of Magna Carta] , see paragraph 33.]

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. [ [http://www.le.ac.uk/ulas/annualreports/ar99-00/hemington/hemington.html Shooting and Fishing the Trent] , ancient fish traps.]

In the UK the traditional form was one or more rock weirs constructed in tidal races with a small gap that could be blocked by fences when the tide turned to flow out again. Surviving examples, but no longer in use, can be seen in the Menai Strait. Because they were so effective they reduced inshore fish stocks and in 1861 Parliament banned their use except where they could be shown to have been in use prior to the Magna Carta. An example of such a fishing weir was at Rhos Fynach in North Wales, which survived in use until World War I. [http://www.bbc.co.uk/wales/northwest/sites/walks/pages/rhos1.shtml Reid, Ian (2001): "Rhos-on-Sea Heritage Trail".] BBC Wales North West website retrieved 7 August 2007.]

An enormous 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 Amazonian savannah [http://www.nature.com/nature/journal/v408/n6809/abs/408190a0.html Erickson, Clark (2000): "An artificial landscape-scale fishery in the Bolivian Amazon".] Nature, 408(6809):190-193 ] . These earthworks cover over 500 km^2, and appear to have supported a large and dense population around 3000 B.C. See also Dr. Erickson's research website [http://ccat.sas.upenn.edu/fishweir/ Erickson, Clark (2000b): "AN ARTIFICIAL LANDSCAPE-SCALE FISHERY IN THE BOLIVIAN AMAZON"] University of Pennsylvania website retrieved 12 Oct. 2007] . An approximate location for these sites is 63.4128°W, 13.4812°S.

Types

In North America, fishing weirs are constructed using wooden stakes woven together to create a that water can pass through yet fish cannot. The pattern of wooden stakes depends on the location and nature of the waters being fished.

Natives in Nova Scotia use weirs that stretch across the entire river to retain shad during their seasonal runs up the Shubenacadie, Nine Mile, and Stewiacke rivers, and use nets to scoop the trapped fish. Various weir patterns were used on tidal waters to retain a variety of different species, which are still used today. V-shaped weirs with circular formations to hold the fish during high tides are used on the Bay of Fundy to fish herring, which follow the flow of water. Similar V-shaped weirs are also used in British Columbia to corral salmon to the end of the "V" during the changing of the tides.

ee also

* Double-Heart of Stacked Stones

References

External links

[http://www.gma.org/herring/harvest_and_processing/weirs/default.asp Herring Weirs in the Gulf of Maine] (informational website on the herring fishery in the state of Maine, U.S.A.)