the periods to plot 1952. 



Chinook Yearlings 



The catch of Chinook yearlings peaked 

 in the morning and evening in both years 

 (fig. 5). The morning peak was at 6 a.m. 

 in both years, which is 1 hour eaxlier than 

 that for fingerlings. The evening pesik in 

 1952 was at 9 p.m., and in 1953 a* 8 P-ni- 



10 







I I I I I I I I I I I I I I I I I I I I 



1952: 918 FISH 

 1953 : 646 FISH 



I I I I I I I I I 1_J I I 1 I — I — I — I — I — I — I — I — L 



12 2 4 6 8 10 12 2 4 6 8 10 12 



^■^ HOUR •'^ 



Fi^ura i Hourly catches of Chinook ysarllsgs In 1953 and 1953- 



Each hour repreeants the sumatloQ of the y«ar*B 

 catch for that hour. 



Three 72-hour periods in 1953 were 

 plotted, and morning and evening peaks are 

 evident. The morning peaks did not coin- 

 cide, but occurred at k, 5> and 6 a.m. The 

 evening peaks coincided at 8 p.m. The 

 period from May k to May 7 had a slightly 

 higher 2 p.m. peak than the one at 8 p.m. 

 (fig. 6). 



Bluebacks 



A morning peeik of bluebacks at 7 a.m. 

 occurred in 1952, with the catch gradually 

 diminishing during the succeeding hours. 

 The 1953 data were opposite with noticeable 

 evening and night peaJis (fig. 7). Addi- 

 tional data are needed to detenaine If this 

 graph accurately defines hours of downstream 

 movement. 



Silvers 



In 1952, silvers peaked at 2 and k 

 a.m. ; the third highest mode occured at 

 8 p.m. (fig. 8). After the k a.m. peak 

 the catch fluctuated widely with morning 



1 — 1 — I — 1 — 1 — I — 1 — 1 — 1 — I — I — 1 — 1 — I — I — I — I — I — I — I — I — I — r 



2 2 4 6 8 10 12 2 4 6 8 10 12 



AM 



HOUR 



PM 



APRIL 20-23 114 FISH 



APRIL 28-MAYI 165 FISH 

 MAY 4-7 364 FISH 



Figure 6. — Percent of chinook yearlings 

 caught each hour during three 

 72-hour periods in 1953. 



12 



I I 



10 



9 



8 



7 



6 



T ' I I I — I — I — I — t I I — I — I — n — n — I — I — I — I — I — r 



« 



1952 : 25! FISH 



- — 1953 : 88 FISH 



\ ;\- 



12 2 4 6 8 10 12 2 4 6 8 10 12 

 AM PM 



HOUR 



Figure J. — Hourly catches of bluebacks in 

 1952 and 1953- Each hour repre- 

 sents the summation of the year's 

 catch for that hour. 



