100 -- 



90 -- 



80 -- 



•70 



160 



50 -- 



:40 -- 



E30 -- 



5 20 -- 



10 





NIGHT 

 DAY 



(N = 873) 



(N=3I6) 



(N = 865) 



, (N = 779) 





M 



I -GROUP 

 CHINOOK 



I- GROUP 

 STEELHEAD 



0- GROUP 

 SflLMONIDS 



AMMOCOETES 



AGE GROUP AND SPECIES 



Figure 6. — Comparison of day (7 a.m. to 7 p.m.) and night 

 (7 p.m. to 7 a.m.) catches of juvenile anadromous fish 

 in turbine intalies of The Dalles Dam. Results of IS 

 tests, April 7-27, 1960. 



Table 1. — Diel movemenl oj fingerling salmonids and 

 lamprey ammocoeles in turbine intakes of unit 1 (doivn- 

 stream end), unit 5 {center), and units 10 and 11 {upstream 

 end of powerhouse) at The Dalles Dam 



1 Results of 18 tests, April 7-27, 1960) 



Age groups 

 and species 



I -group Chinook 

 salmon 



I-group steel- 

 head trout 



0-group 

 salmonids 



Ammocoetes 



Catch by powerhouse area ' 



Downstream end 



Night 



Per- 

 cent 



61.2 

 63.5 



Day 



Per- 

 cent 



5.6 

 10.2 



38.8 

 36.5 



Total 



Num- 

 ber 



358 

 118 



201 

 315 



Middle 



Night 



Per- 

 cent 



94.2 

 82.7 



62.5 

 51.1 



Day 



Per- 

 cent 



5.8 

 17.3 



37.5 

 48.9 



Total 



Num- 

 ber 



189 

 127 



248 

 282 



Upstream end 



Night 



Per- 

 cent 



93.9 

 81.7 



71.7 

 75.8 



Day 



Per- 

 cent 



6.1 

 18.3 



28.3 

 24. 2 



Total 



Num- 

 ber 



326 

 71 



416 

 182 



1 See figure 2 for location. 



were caught at night. Of the O-group salmonids 

 and ammocoetes, 67 and 62 percent, respectively, 

 were caught at night. 



Results reported here agree generally with those 

 of other investigators of day and night movement 

 of fingerlings. In the undammed sections of the 

 Snake and Columbia Rivers, most of the I-group 

 Chinook salmon and I-group steelhead trout were 

 captured from 6 p.m. to 6 a.m. (Mains and Smith, 

 footnote 3) . In research in special byjjasses at Bon- 

 neville Dam, Gauley et al. (1958) found signifi- 



cantly more O-group chinook salmon, I-group 

 Chinook salmon, and I-group steelhead trout mi- 

 grating from 6 p.m. to 6 a.m. in 4 out of 5 seasons — 

 1946, 1949, 1950, and 1953. More recently, Monan, 

 McConnell, Pugh, and Smith (unpublished) " 

 caught a majority of salmonid fingerlings (mixed 

 species) between 8 p.m. and 6 a.m. in the Snake 

 River. 



VERTICAL DISTRIBUTION 



Vertical distribution of juvenile anadromous 

 fish migrating through turbine intakes of The 

 Dalles Dam (intake B of imits 1, 5, 6, 10, and 12) 

 and of McNary Dam (intake C of unit 12) is ]3re- 

 sented in tables 2 through 8 and figures 7 and 8. 



Table 2 — Vertical distribution of O-group salmonids in 

 turbine intakes of The Dalles Dam. Combined results of 

 14 tests extending from 3:30 p.m. to 8:30 a.m. 



(Test period, April 28 to May 12, 1960] 



' From ceiling of intake at gatewell. 



Table 3. — Vertical distribution of I-group chinook salmon 

 fingerlings in turbine intakes of The Dalles Dam. Com- 

 bined results of 14 tests extending from 3:30 p.m. to S:30 

 a.m. 



(Test period. April 28 to May 12. 1960) 



I From ceiling of intake at gatewell. 



■ Monan, Gerald E., Robert J. McConnell, John R. Pugh, and 

 Jim R. Smith. Distribution of downstream migrant salmonids and 

 the .study of debris in the Snake River above Bro\vnlee Reservoir. 

 Fish-Passage Research Program, Bureau of Commercial Fisheries, 

 Seattle, Wash. Manuscript in preparation. 



.lUVENILE AXADROMOUS FISH IN TURBINE INTAKES 



605 



