FISHERY INDUSTRIES. $6 



the factors which dotoriniuc the vuriatioiis in run from year to year. It can hardly 

 he a question of temperature, or of heiglit and quality of water, for all the streams are 

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

 year to year. 



In 1908 the run socnis to liavo jj^onc to tlio south side of tjic hay, 

 ratlier tlian to liave passed tjie s'ulc streams to enter that at tlie head 

 of tlie bay; all of the streams of the peninsula from the Ugusliik uj) 

 had good rims. 



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

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

 iish, the former ])robably preponderating in the schools 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 out])ut of salmon. 

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

 proportional to the number of spawning fisJi reaching the beds. 

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

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

 certain seasons herring reproduce much more effectively than in 

 other seasons; the increased number of individuals orighiating 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 physical 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 limited 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 in 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 tliat there is a 

 ])oint of maximum effectiveness beyond wliich 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 wliile the 325,000 spawners of 1912 will produce a greater 

 relative outi)ut, i. e., more adult fish per thousand spawners, the 

 total number of adults derived from this spawning wiU 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 



