All About the Fish Weir

A Tool of Subsistence Farmers for 8,000 Years or More

Deer Island Fish Weir in the Fog (New Brunswick, Canada)

Leonora Enking / Flickr / CC BY-SA 2.0

A fish weir or fish trap is a human-made structure built of stone, reeds, or wooden posts placed within the channel of a stream or at the edge of a tidal lagoon intended to capture fish as they swim along with the current.

Fish traps are part of many small-scale fisheries around the world today, supporting subsistence farmers and sustaining people during difficult periods. When they are built and maintained following traditional ecological methodologies, they are secure ways for people to support their families. However, local management ethics have been undermined by colonial governments. For example, in the 19th century, British Columbia's government passed laws to prohibit fisheries established by First Nations people. A revitalization effort is underway.

Some evidence of their ancient and continuing use is found in the wide variety of names still used for fish weirs: fish impoundment, tidal weir, fishtrap or fish-trap, weir, yair, coret, gorad, kiddle, visvywer, fyshe herdes, and passive trapping.

Types of Fish Weirs

Regional differences are apparent in construction techniques or materials used, species harvested, and of course terminology, but the basic format and theory are the same worldwide. Fish weirs vary in size from a small temporary brush framework to extensive complexes of stone walls and channels.

Fish traps on rivers or streams are circular, wedge-shaped, or ovoid rings of posts or reeds, with an upstream opening. The posts are often connected by basketry netting or wattle fences: the fish swim in and are trapped within the circle or upstream of the current.

Tidal fish traps are typically solid low walls of boulders or blocks built across gullies: the fish swim across the top of the wall at spring high tides, and as the water recedes with the tide, they are trapped behind it. These types of fish weirs are often considered a form of fish farming (sometimes called "aquaculture"), since the fish can live in the trap for a period until they are harvested. Often, according to ethnographic research, the fish weir is regularly dismantled at the beginning of the spawning season, so fish may freely find mates.

Invention and Innovation

The earliest fish weirs known were made by complex hunter-gatherers all over the world during the Mesolithic of Europe, the Archaic period in North America, the Jomon in Asia, and other similarly dated hunter-gatherer cultures around the world.

Fish traps were used well into the historic period by many groups of hunter-gatherers, and in fact, still are, and ethnographic information about historic fish weir use has been gathered from North America, Australia, and South Africa. Historical data has also been collected from medieval period fish weir use in the UK and Ireland. What we've learned from these studies gives us information about the methods of fish trapping, but also about the importance of fish to hunter-gatherer societies and at least a glimmer of light into traditional ways of life.

Dating Fish Traps

Fish weirs are difficult to date, in part some of them were used for decades or centuries and were dismantled and rebuilt in the same locations. The best dates come from radiocarbon assays on wooden stakes or basketry which were used to construct the trap, which only dates the latest rebuild. If a fish trap was completely dismantled, the likelihood that it left evidence is very slim.

Fishbone assemblages from adjacent middens have been used as a proxy for the use of a fish weir. Organic sediments such as pollen or charcoal in the bottoms of traps have also been used. Other methods used by scholars include identifying local environmental changes such as changing sea level or the formation of sandbars that would impact the weir's use.

Recent Studies

The earliest known fish traps to date are from Mesolithic sites in marine and freshwater locations in the Netherlands and Denmark, dated to between 8,000 and 7,000 years ago. In 2012, scholars reported new dates on the Zamostje 2 weirs near Moscow, Russia, of more than 7,500 years ago. Neolithic and Bronze Age wooden structures are known at Wooton-Quarr on the Isle of Wight and along the shores of the Severn estuary in Wales. The Band e-Dukhtar irrigation works of the Achaemenid dynasty of the Persian Empire, which includes a stone weir, dates between 500–330 BCE.

Muldoon's Trap Complex, a stone-walled fish trap at Lake Condah in western Victoria, Australia, was constructed 6600 calendar years ago (cal BP) by removing basalt bedrock to create a bifurcated channel. Excavated by Monash University and the local Gundijmara Aboriginal community, Muldoon's is an eel-trapping facility, one of many located near Lake Condah. It has a complex of at least 350 meters of constructed channels running alongside an ancient lava flow corridor. It was used as recently as the 19th century to trap fish and eels, but excavations reported in 2012 included AMS radiocarbon dates of 6570–6620 cal BP.

The earliest weirs in Japan are currently associated with the transition from hunting and gathering to farming, generally at the end of the Jomon period (ca. 2000–1000 BC). In southern Africa, stone-walled fishtraps (called visvywers) are known but not direct-dated as of yet. Rock art paintings and fishbone assemblages from marine sites there suggest dates between 6000 and 1700 BP.

Fish weirs have also been recorded in several locations in North America. The oldest appears to be the Sebasticook Fish Weir in central Maine, where a stake returned a radiocarbon date of 5080 RCYPB (5770 cal BP). Glenrose Cannery at the mouth of the Fraser River in British Columbia dates to about 4000–4500 RCYBP (4500-5280 cal BP). Fish weirs in southeastern Alaska date to ca. 3,000 years ago.

A Few Archaeological Fish Weirs

  • Asia: Asahi (Japan), Kajiko (Japan)
  • Australia: Muldoons Trap Complex (Victoria), Ngarrindjeri (South Australia)
  • Middle East/West Asia: Hibabiya (Jordan), Band-e Dukhtar (Turkey)
  • North America: Sebasticook (Maine), Boylston Street Fish Weir (Massachusetts), Glenrose Cannery (British Columbia), Big Bear (Washington), Fair Lawn-Paterson Fish Weir (New Jersey)
  • UK: Gorad-y-Gyt (Wales), Wooton-Quarry (Isle of Wight), Blackwater estuary weirs (Essex), Ashlett Creek (Hampshire)d
  • Russia: Zamostje 2

The Future of Fish Trapping

Some government-sponsored programs have been funded to blend traditional fish weir knowledge from indigenous peoples with scientific research. The purpose of these efforts is to make fish weir construction safe and productive while maintaining ecological balances and keeping the costs and materials within the range of families and communities, especially in the face of climate change.

One such recent study is described by Atlas and colleagues, on weir construction for the exploitation of sockeye salmon in British Columbia. That combined work by members of the Heiltsuk Nation and Simon Fraser University to rebuild weirs on the Koeye River, and establish fish population monitoring.

A STEM (science, technology, engineering, and mathematics) education program has been developed (Kern and colleagues) to engage students in the construction of fish weirs, the Fish Weir Engineering Challenge.


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Hirst, K. Kris. "All About the Fish Weir." ThoughtCo, Feb. 16, 2021, Hirst, K. Kris. (2021, February 16). All About the Fish Weir. Retrieved from Hirst, K. Kris. "All About the Fish Weir." ThoughtCo. (accessed June 6, 2023).