recovery data that there was no spawning in 

 Skilak Lake or its small tributaries. Actually, 

 it is impossible to see tagged fish in the lake, 

 and the amount of spawning there is unknown. 



Seasonal Changes in Size and Age 

 Composition and Sex Ratio 



There were seasonal changes in the size 

 and age composition, and in the sex ratio of 

 red salmon taken in fyke traps at the index 

 site. These changes were probably in part 

 natural characteristics of the runs, but they 

 also reflected effects of the intensive gill net 

 fishery in Cook Inlet. 



The gill net fishery was not active during 

 the time the early run of red salmon passed 



through the Inlet and entered the Kenai River. 

 Thus, in 1Q57 the fish taken in the fyke traps 

 between June 6 and July 7 apparently had not 

 been subjected to the selective action of a gill 

 net fishery and were larger than fish taken 

 later in the migration (figs. 8 and 9). This 

 tendency toward a decrease in average size 

 during the season did not appear to be as 

 pronounced in the 1958 and 1959 catches. 



Also, there was a difference in the average 

 size of fish taken in the traps between years. 

 Both male and female fish were progressively 

 smaller in successive years. This decrease 

 in size is understandable when the age com- 

 position of the run is considered for each 

 year (fig. 10). In 1958 and 1959 there were 



20 



I 5 



10 



r 



400 



20 



15 



10 



400 



20 



o- I 



400 



Figure 8.- -Size composition of male and female red salmon taken in fyke traps in the Kenai River 



during migrations, 1957-59. 



II 



