Stone fish traps have been used for thousands of years in many places around the world. A fish weir or trap is generally an obstruction placed in tidal waters, or wholly or partially across a river, to direct the passage and trap fish. Fish traps may be used to trap fish in the intertidal zone as the tide recedes, anadromous fish such as salmon as they attempt to swim upstream to spawn in a river, or eels as they migrate downstream. In the Pacific Northwest, fish traps are used to take the best advantage of the large tide range. V-shaped weirs are often used in Alaska and the Pacific Northwest to corral salmon during the changing of the tides. Read more here and here. See a short video of a British Columbia fish trap in action here. Click here to download the CoastView app and explore Mink Bay.