INVESTIGATIONS CONCERNING THE RED-SALMON RUNS 

 TO THE KARLUK RIVER, ALASKA 



By CHARLES H. GILBERT and WILLIS H. RICH 



CONTENTS 



Page 



Introduction 1 



Karluk River watershed 4 



Statistical history of the fishery 6 



Observations on the spawning grounds... 9 



Page 



Life history of Karluk red salmon 27 



Analyses of recent runs 35 



Escapements and total runs, 1921 to 1926. 58 

 Bases for prediction of future runs 63 



INTRODUCTION 



The history of the Alaska salmon industry, until within the last few years, has 

 been one of consistently increasing exploitation without regard to its effect on existing 

 salmon supplies. In every district, as salmon stocks dwindled under this regime, 

 the intensity of fishing effort was redoubled, and the amount of fishing gear in opera- 

 tion was increased by leaps and bounds in the attempt to maintain unimpaired, or 

 to increase if possible, the size of the commercial pack. The necessity of making 

 provision for future runs was ignored. No attention was given to the number of 

 spawning fish that succeeded in escaping the nets. No one concerned himself with 

 the size of the spawning reserves or their adequacy to maintain the runs. The 

 congressional regulations in effect were hopelessly inadequate and the Bureau of 

 Fisheries was without power to act. 



Such a system could have only one result — the eventual depletion of the salmon 

 supplies and the final extinction of the industry. This result was clearly foreshadowed 

 in the years succeeding the close of the Great War and had been hastened, doubtless, 

 by the extraordinary efforts during the course of the war to increase the salmon pack 

 to the utmost, as a patriotic duty. Be that as it may, the conviction became uni- 

 versal, in the years following the armistice, that the salmon industry, by the methods 

 then employed, was courting complete disaster and could be saved only by being 

 subjected to close supervision under well-devised regulations. 



To meet this emergency, Congress in 1924 enacted a law for the protection of 

 the fisheries of Alaska, in which very wide regulatory powers were conferred on the 

 Secretary of Commerce for the purpose of preventing further depletion of the salmon 

 runs and of restoring them as nearly as possible to their former condition of abundance. 

 Under his direction the Bureau of Fisheries has grappled with this problem. 



Fortunately, considerable progress had been made prior to 1924 in ascertaining 

 important facts in the life histories of our salmon. It was known that there are 



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