|Document Type:||Contract Report|
|Title:||Research at McNary Dam to improve fish guiding efficiency of yearling and subyearling Chinook salmon, 1987|
|Author/Editor:||Dean A. Brege, William T. Norman, George A. Swan, John G. Williams|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||U.S. Army Corps of Engineers. Portland, Oregon|
McNary Dam on the Columbia River was completed in 1954 without specific provisions for juvenile fish passage. All downstream migrants either passed through the turbines or over the spillway. Research in ensuing years found that turbine passage and migration through reservoirs were detrimental to salmon survival. Upon development of a means to intercept fish passing through turbines, the U.S. Army Corps of Engineers constructed a juvenile collection system at McNary Dam with submersible traveling screens to collect fish and transport them to a release site below the hydrosystem.
Evaluations of these screens during the spring migration found fish guiding efficiencies (FGE) of over 70% for yearling spring chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss. Studies of subyearling chinook salmon during the summers of 1982 and 1984 yielded FGEs of 33 60%.
In 1987, we continued research at McNary Dam to assess increases in FGE obtained by using a lowered submersible traveling screen, raised operating gate, and trash-rack deflector with both yearling spring and subyearling fall chinook salmon. From tests in 1987, we arrived at the following conclusions: