Laboratory Evaluation of a Denil-Type Steeppass Fishway with Various Entrance and Exit Conditions for Passage of Adult Salmonids and American Shad
adult, Alosa sapidissima, American shad, chinook, coho, denil, downstream fish passage, entrance, fish passage, hollow weir, Little Goose Dam, Oncorhynchus tshawytscha, pool, pool and weir, salmon, salmonids, screens, shad, Snake River, sockeye salmon, steelhead, steeppass, trout, weir
Journal or Book Title
Marine Fisheries Review
This research was designed to determine the feasibility of using a Denil-type fishway as part of a system to trap marked adult salmon and trout ascending a pool-and-overfall fishway at Little Goose Dam on the Snake River. Several entrance and exit situations were tested along with two methods (hollow weir and a pool) of supplying water to the Denil. Water supplied directly to the Denil through a hollow weir provided the best passage conditions for chinook salmon (Oncorhynchus tshawytscha), sockeye salmon (O. nerka), steelhead trout (Salmo gairdneri) and American shad (Alosa sapidissima). Salmonids and shad readily entered and ascended a Denil fishway when the downstream end was submerged to a depth of 2.5 feet. Chinook salmon, coho salmon (O. kisutch), and steelhead trout readily passed through a Denil steeppass fishway that was 50 feet long and positioned at a slope of 28.7 percent.