Table 5, — Number of migrants and percentage survival by age groups of sockeye smolts In migrations from 



Little Kitoi, Ruth, and Midarm Lakes, 1954--59 brood years 



Based on average number of eggs per female. 

 ^ Estimated on basis of a 30-percent survival from egg to fry; see table 6 and later discussion for details. 



LITTLE KITOI LAKE 



60 



^ 



Figure 5. — Magnitude of migrations and percentage sur- 

 vival of sockeye salmon to smolt stage by brood year. 

 Little Kitoi and Ruth Lakes, 1954-59. 



The fry-to-smolt survival in Little Kitoi 

 Lake would have ranged from a low of 5 per- 

 cent for the 1961 brood year to a high of 28 

 percent for the 1957 brood year {table 6). For 

 the same brood years 1955-59, the assumed 

 unweighted average fry-to-smolt survival for 

 Little Kitoi Lake would be 14 percent. This is 

 considerably less than the actual unweighted 

 average fry-to-smolt survival in Ruth Lake 

 of 24 percent. If the assumed egg-to-fry sur- 

 vival in Little Kitoi Lake was actually greater 

 than 30 percent, then the fry-to-smolt sur- 

 vival would be less than 14 percent, and Ruth 

 Lake would appear to have provided an even 

 greater survival for rearing juvenile sock- 

 eye. 



Relation of Population Density 

 to Survival 



Survival to the smolt stage of fry planted 

 in Ruth Lake was considerably lower in 1959 

 and 1960 (1958 and 1 959 brood years) than in 

 earlier years (table 5), The plant of only 

 50,000 in 1959 resulted in the lowest survival 

 (as well as the greatest percentage of hold- 

 over) throughout the study. The environment 

 may have had an adverse effect on this par- 

 ticular plant, or the relatively large number 

 of fingerlings in the lake from the plant of 

 110,000 fry in 1958 may have depressed the 

 survival of the 1959 plant. The relatively low 

 survival of the heavy I960 stocking (425,000 

 fry) may have been the result of overstocking, 

 but this relation cannot be proved because of 

 the still lower survival of the 1958 plant. 



