Of the many different kinds of salmon fishing gear found on the Northwest Coast, weirs have been the most productive. Weirs are fence-like structures made of a row of wooden stakes that have latticework woven in-between them. They were constructed in estuaries, streams, and shallow rivers. Water was able to flow through these fences, but the salmon that were trying to swim upstream to spawn could not pass through them. As the salmon milled about trying to find a way around the fence, they were easily speared, netted, or guided into nearby traps.
On large streams, building a weir required the co-operation of an entire village. The salmon caught in these large weirs were owned and shared by everyone in the village. However it was the weir fishing sites that were owned and reused, rather then the actual weir itself, year after year. Some weir fishing sites, often across small streams, might be owned by only one person or by a family of high rank.
The stake frame of the weir was left up year long, however, the latticework sections were removed until the next fishing season so that they would not be damaged before they were used again. Some latticework sections were also removed during the fishing season to allow some salmon to continue upstream to spawn. These sections were also removed to allow upstream First Nations groups access to the salmon as well. There was a delicate balance of resource sharing among the various First Nations peoples. Often, if a salmon run was poor one year and a group did not get enough fish for the winter, another group that was lucky enough to get their supply of fish would share and trade with the first group so that they could make it through the winter.
Another kind of weir was the tidal weir. These weirs worked on the principle that fish would move with the high tide, and then get trapped in the weir when the tide went back out again. For instance, a V-shaped wooden weir would allow salmon to travel over it at high tide but would force the fish to swim down into the trap at low tide. Other tidal weirs were built of rocks and stakes that trapped the fish on dry land or in pools when the tide went out.
When Europeans arrived in British Columbia they quickly recognized the effectiveness of fish weirs; as a result, a number of large commercial weirs were built. When the number of salmon migrating upriver began to decrease, it was attributed to First Nations fishing weirs. The government feared that the weirs were being used improperly and that not enough salmon were being allowed through to spawn. As a result, the BC government eventually banned the use of all weirs.
One can still see the remains of fish weirs along the coast and rivers of Vancouver Island. During very low tides the remnants of a Coast Salish weir can still be seen across from the Tyee Plaza in Campbell River. Another V-shaped weir structure that corralled fish into a trap was once situated behind McDonalds Restaurant. However, construction of the Discovery Plaza has now obliterated all traces of this weir.