results similar to those shown when the 

 McNary-type crest was used. 



4. A minor change in the original design of 

 the weir baffles (squared corners rather than 

 chamfered corners on downstream face) im- 

 proved the weir overfall condition. 



5. Observations on the effect of various 

 flow conditions on passage of fish showed that 

 both Chinook salmon and steelhead trout made 

 significantly faster ascents under an overfall 

 and orifice flow condition when the head on the 

 weir was increased from 0.95 foot to 1.20 feet. 

 With the orifices closed, both species made 

 significantly slower ascents when the head on 

 the weirs was increased from 0.95 foot to 1.20 

 feet. When only orifice flows were provided, 

 steelhead ascended the fishway in less time 

 than under any of the other conditions tested. 

 Chinook salnnon appeared to accept quite 

 readily the orifice -flow-only condition and 

 ascended the fishway without apparent diffi- 

 culty. 



6. The preference of various species offish 

 for orifices or overfalls during ascent was 

 examined at the uppernnost weir of the fishway. 

 Chinook salnnon preferred orifice passage 

 during the early part of the season and re- 

 versed this preference as the season 

 progressed. Early runs of steelhead preferred 

 the overfall and later runs the orifice. Gen- 

 erally, preference ratios were about 60 to 40. 

 Over 85 percent of sockeye salmon used the 

 overfall passage during ascent. 



Among other fish observed were carp, 

 shad, squaw^fish, and suckers. Eighty-three to 

 one hundred percent of the carp, squawfish, 

 and suckers used the orifice passage. Shad 

 favored the overfall. 



Results of performance of salmonids in the 

 new 1-on- 10-slope Ice Harbor fishway were 

 compared with similar data from previous 

 tests in a 1-on- l6-slope fishway. Comparisons 

 indicate that a 1-on- 10-slope fishway of the 

 design tested is as suitable for passage of 



fish as conventional 1-on- l6-slope fishways 

 now used on the Columbia River. 



LITERATURE CITED 



COLLINS, GERALD B., and CARL H. ELLING. 

 1960. Fishway research at the Fisheries- 

 Engineering Research Laboratory. U.S. 

 Fish and Wildlife Service, Circular 98, 

 17 p. 



COLLINS, GERALD B., CARL H. ELLING, 

 JOSEPH R. GAULEY, and CLARK S. 

 THOMPSON. 

 1963. Effect of fishway slope on perform- 

 ance and biochemistry of salmonids. 

 U.S. Fish and Wildlife Service, Fishery 

 Bulletin, vol. 63, no. 1, p. 221-253. 



DIXON, WILFRID J., and FRANK J. MASSEY, 

 JR. 

 1957. Introduction to statistical analysis. 

 2d ed. McGraw-Hill Book Company, 

 New York, 48 p. 



ELLING, CARL H. 



I960. Further experiments in fishway ca- 

 pacity, 1957. U.S. Fish and Wildlife 

 Service, Special Scientific Report-- 

 Fisheries No. 340, 16 p. 



ELLING, CARL H., and HOWARD L. RAY- 

 MOND. 



1959. Fishway capacity experiment, 1956. 

 U.S. Fish and Wildlife Service, Special 

 Scientific Report--Fisheries No. 299, 

 26 p. 



GAULEY, JOSEPH R. 



1960. Effect of fishway slope on rate of 

 passage of salmonids. U.S. Fish and 

 Wildlife Service, Special Scientific Re- 

 port--Fisheries No. 350, 23 p. 



GAULEY, JOSEPH R., and CLARK S. THOMP- 

 SON. 

 1963. Further studies on fishway slope and 

 its effect on rate of passage of salnn- 

 onids. U.S. Fish and Wildlife Service, 

 Fishery Bulletin, vol. 63, No. 1, p. 45- 

 62. 



MS. #1406 



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