CATCH (PERCENT) 

 20 40 60 80 100 



H — \ — M — \ — \ — I — I — \ — \— 



^^^^ 



0-44 



I GROUP CHINOOK 

 N = I,I80 



I GROUP STEELHEAD 

 N=35l 



1 GROUP SOCKEYE 

 N = 424 



0-4 4^^^^^ 



4.6-9.0 

 9.2-13. 6 



0-4 4^^„__ 



4.6-9.0 ___^^^_ 

 9.2-I3.613SSSSS 



GROUP SALMONIOS 

 N= 1,074 



AMMOCOETES 

 N = l.679 



Figure 7. — Combined results of 14 tests showing vertical 

 distribution of juvenile anadromous fish in turbine in- 

 takes of The Dalles Dam. Each 16-hour test was between 

 3 :30 p.m. and 8 :30 a.m. Test period, April 28 to May 

 12, 1960. 



DISTRIBUTION (PERCENT) 

 20 40 60 



-1 1 h 



9 2-13 etixixvj 



Figure 8. — Combined results of 10 tests showing vertical 

 distribution of fingerling salmonlds in intake 12-C at 

 McXary Dam. Each 8-hour test was between 7 p.m. and 

 5 a.m. Test period, April 24 to May 26, 1961. 



of the powerhouse occurred in the bottom two of 

 the six nets, whereas the zone of highest concen- 

 tration was in the two center nets in the center 

 and downstream end of tlie powerliouse. This dif- 

 ference was statistically significant. 



Catches at McNary Dam showed that the verti- 

 cal distribution of I-group chinook and sockeye 

 salmon and I-group steelhead trout was much 



the same as the vertical distribution of these age 

 groups and species at The Dalles Dam. The I-group 

 chinook salmon and steelhead trout were most 

 strongly concentrated in the top two nets (79.3 

 and 73.5 percent, respectively), whereas I-group 

 sockeye salmon were somewhat less concentrated 

 (62.3 percent). 



IMPLICATIONS OF RESEARCH 

 IN TURBINE INTAKES 



Information on diel movement and vertical dis- 

 tribution of fingerling salmonids in turbine intakes 

 applies directly to the problem of developing 

 methods for reducing fingerling mortality in Ka^j- 

 lan turbines. Important implications are discussed 

 below. 



DIEL MOVEMENT 



According to past research, day and night move- 

 ment of fish can vary significantly from year to 

 year, presumably because of changes in turbidity 

 and other facets of w-ater quality. Mains and 

 Smith (footnote 3) caught 57 percent of the 

 I-group chinook salmon at night in the Snake 

 Eiver in 195-1, whereas in 1955 they caught 78 per- 

 cent at night. Gauley et al. (1958) caught signifi- 

 cantly more 0-group chinook salmon and I-grouj) 

 steelhead trout in special bypasses at Bomieville 

 Dam during the night in -1 of 5 seasons; but in 

 1952, .significantly more of these species were 

 caught by day. Data by Gauley et al. (1958) sug- 

 gested that turbidity may have influenced timing 

 of fish movement. In view of past research, the 

 data on day and night movement reported here 

 should be applied with some reservation because 

 continuing development of the river system may 

 well alter water quality, including turbidity, in the 

 future. 



Although data on day and night movement 

 must l)e considered only partially complete, the 

 results — especially for I-group fingerlings — sug- 

 gest a fortunate relation between timing of fish 

 passage at dams and the normal schedule of tur- 

 bine loading. Night movement of fish through tur- 

 bines favors higher rather than lower average 

 survival. At night tlie decreased demand for power 

 causes reduced turbine loads. Preliminary infor- 

 mation recently obtained at Big Cliff Dam « indi- 



* Oligher. Ray. Fish passage through turbines — tests at Big 

 Cliff hydroelectric plant. U.S. Army Corps ot Engineers, North 

 Pacific Division. Walla Walla District. Walla Walla, Wash. Letter 

 report (1965), 14 pp. 



.JUVENILE ANADROMOUS FISH IN" TURBINE INTAKES 



607 



