FISHERY INDUSTRIES. 25 



the factors which determine the variations in run from year to year. It can hardly 

 be a question of temperature, or of height and quality of water, for all the streams are 

 subject to essentially the same climatic conditions and would vary together from 

 year to year. 



In 1908 the run seems to have gone to the south side of the bay, 

 rather than to have passed the side streams to enter that at the head 

 of the bay; all of the streams of the penmsula from the Ugushik up 

 had good runs. 



The large run of 1912 is undoubtedly the result in large measure of 

 the heavy run of 1908. Scale examination shows both 4 and 5 year 

 fish, the former probably preponderating m the scliools captured 

 off the Kvichak-Naknek regions. As yet the study of the scales is 

 too incomplete to make positive statements. It would seem, how- 

 ever, that a considerable number of the 1908 spawning should be 

 expected to return in 1913. Perhaps not sufficient regard has been 

 given to the seasonal effect upon the reproductive output of salmon. 

 We are accustomed to rate the effective result in adults as directly 

 proportional to the number of spawning fisii reaching the beds. 

 That this leaves many factors unaccounted for is evident at once. 

 Unknown conditions vary the output. It is well understood that in 

 certain seasons herring reproduce much more effectively than in 

 other seasons; the increased number of individuals originating in a 

 particular year showing throughout several succeeding years as a 

 higher proportionate number in the total school. This augmenta- 

 tion is probably due to pliysical factors and such factors must in the 

 same way influence the output of salmon. 



In addition to these uncontrollable natural factors, large numbers 

 of spawners on the lunited spawning beds of the salmon must result 

 in a different ratio of fry to eggs deposited as contrasted with results 

 from a smaller number of spawners. That is, if 2,600,000 spawners 

 reached Lake Aleknagik m 1908, and only 325,000 in 1912, it does 

 not follow that the returns of the 1912 spawning will be less than 

 one-eighth of that of 1908. But even if it be true that there is a 

 point of maximum effectiveness beyond which the relative output 

 decreases, it must also be true that, aside from the influence of 

 physical factors not under control, the greater the number of spawn- 

 ers reaching the lake the greater the total number of young produced; 

 so that while the 325,000 spawners of 1912 will produce a greater 

 relative output, i. e., more adalt fish per thousand spawners, the 

 total number of adults derived from this spawning will be far fewer 

 than the number derived from the 2,600,000 spawners of 1908. 



The researches of Dr. Gilbert on the Fraser River sockeyes have 

 demonstrated that an almost negligible number of the adult sockeyes 

 are from young which went to sea as fry, i. e., without one winter in 

 fresh water. Observations in Wood River and elsewhere tend to 



