3» A comparison was ir.ade hotween the numbers of injiird fish 

 appearing in the adult chinook salmon run arrivinp, at Pig IVhite SaLrion 

 Hatchery, about 30 miles above Bonneville Dam, and at Bonneville Hatchery, 

 about one mile below Bonneville Dar « Ho great difference was found to 

 exist in the percent of injured fish at the two locations , For example, 

 2 3 percent of the fish examined at Big V/hite Salmon Hatchery had dorsal- 

 fin abrasions, and slightly more, or 26o5 percent, of the fish below the 

 dam at Bormeville Hatchery had similar injuries. These injuries were 

 undoubtedly caused by fishermen's nets. Other types of injuries, the 

 origin of which is not knowrij occurred in 1.7 percent of the salmon 

 examined at Big White and 2.4 percent of the salmon examined at 

 Bonneville station. 



4. A submersible observation chamber was constructed by the U» S* 

 Corps of Engineers for the purpose of directly observing and making a 

 photographic record of the action of salmon passing through submerged 

 orifices in one of the fish ladders at Bonneville Dam. Neither the 

 direct observations nor the moving picture records showed fish being 

 injured in ladder. 



5. One hundred wood floats, simulating floating dead salmon, were 

 released at Bonneville Dam to determine the time required for fish that 

 might die at Bonneville to be carried downstream past Ellsworth cannery. 

 On August 28, 1946, when the river was flowing 92,000 cubic feet per 

 second, the average rate of flow of the rivpr was foim'l to be between 

 1.C3 and 1.61 miles per hour. Therefore, floating dead fish at Bonneville 

 Dam should drift by Ellsworth cannery (33 miles belov/) about 43 hours 

 after leaving the dam. Since about 72 hours are required for salmon to 



be buoyed up sufficiently to be carried by the current,* the total time 

 elapsing between the death of a fish at Bonneville and its appearance 

 as a floating carcass at Ellsworth should be approximately 115 hours. 



6. A count of the nurabers of floating dead salmon above and below 

 Bonneville Dam was made during the peak of the fall run in 1946. During 

 64 hours of observations over an 8-day period, 10 dead salmon were seen 

 floating by Ellsv/orth cannery, and 3 dead salmon and one dead steelhead 

 were observed en route to Bonneville Dam from Ellsv/orth on September 18 

 and 19. Fourteen dead salmon and steelheed were recorded and tagged as 

 they passed Cape Horn (about 13 miles below Bonneville). These fish were 

 not observed at Ellsworth, Tfashington. In addition to the fish floating 

 past Cape Horn, the observers noted 13 dead fish beached on the shore 

 between Cape Horn and Bonneville Dam. Thus, in about 72 hours of search 

 between the dam and Cape Horn, 27 dead fish were counted. Above Bonne- 

 villa Dam, the observers saw 104 dead fish in about 86.5 hours of intensive 

 search during the same period. 



«Wade, 1945, see Appendix. 



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