412 American Fisheries Society 



of them seem to be very serious. It is clear that in the period 

 in which fishing is permitted, the taking of fish will be pursued 

 with maximum intensity and every effort be made to secure 

 the largest possible number of fish during the open season. 

 If all the fish that entered a given stream were bound for the 

 same spawning ground and if conditions for their progress 

 upstream and for the deposit of eggs at the spawning ground 

 were uniform at all periods, then this method would only have 

 the disadvantage that if fishing were practiced too assiduously 

 during the period of maximum movement or if by weather 

 conditions the run of salmon were concentrated more nar- 

 rowly than usual, then the percentage of the total run that 

 would be taken might easily exceed that which was desirable. 

 Many observers have noted the fact that when weather con- 

 ditions hold back the fish, because especially of low water in 

 the streams, and then abundant rains cause the streams to 

 rise suddenly, the fish will go up with a rush. This is a char- 

 acteristic phenomenon in southeastern Alaska on the smaller 

 streams. It means that the fish are schooled longer than usual 

 in the estuaries, and because of their having been brought to- 

 gether can be seined more easily and the complete run be 

 caught with the minimum effort. 



The case is somewhat different in those large rivers pro- 

 vided with numerous spawning grounds. Here the stage of 

 water plays a very minor part, and significant fluctuations are 

 not noticed in the lower courses of the stream. Furthermore, 

 in such cases the migration continues over a much more ex- 

 tended period of time. The evidence which I have given from 

 our studies on the Copper River substantiates fully the ob- 

 servations of Gilbert and Babcock on the Fraser River. The 

 fish which start first are bound to one spawning ground, and 

 those which follow at subsequent intervals are distributed over 

 other spawning territory. In such an instance as this, to per- 

 mit intensive fishing during the early part of the run would 

 eliminate from reproduction a very large proportion of those 

 going to a particular spawning place, and might indeed sub- 



