COPPER RIVER INVESTIGATION. 129 



the dip netters will get nearly all of the fish that are passing upstream 

 on that side. 



Some persons interviewed thought that many fish went upstream 

 through the center. As an evidence of this they asserted positively 

 that they had seen the back fins of the salmon breaking the surface 

 far out and even at the center of the cm-rent. There is no reason to 

 doubt this statement in so far as it rests upon an observation made, 

 for the observers were careful and conscientious men, and in numerous 

 instances, no doubt, they had seen the back fins of the salmon appear 

 above the sm-face and disappear below it at considerable distances 

 from the bank. On the other hand the inference drawn seems open 

 to grave doubt. Let it be remembered that no one can follow the 

 course of the fish even for a short distance after the fin has once 

 passed below the surface of the water. Furthermore, in such cases 

 the fin is in sight for a moment only, appearing and disappearing 

 almost instantaneously. The author has often seen similar appear- 

 ances in other places and has found them connected with conditions 

 entirely different from those that were inferred in this case. 



Salmon attempting to ascend an extended rapids against a power- 

 ful current make a dash through a stretch where they feel the full 

 force of the stream, and if they are diverted from their path by some 

 swerving of the current, or if they fail to select precisely the right 

 direction to bring them under shelter before the energy of their dash has 

 subsided, they are caught by the full force of the stream and carried 

 downward. It is easy to interpret such conditions when one can 

 follow the fish in water that is more or less transparent. Under the 

 circumstances here it is evident that the direction of the fish can not 

 be followed unless the fin is visible and the brief period in which it 

 can be seen is no index whatever of the general movement of the fish. 

 Under the conditions as they exist at present there is no doubt that 

 a considerable number of fish ascend the stream along the east bank, 

 resting in the large eddies referred to previously. Even if fishing on 

 the west bank eliminates a considerable percentage of the run, the 

 protection offered by the east bank will probably allow a goodly 

 number of fish to make their way upstream unhindered, though 

 there is no evidence at hand to indicate whether the majority of the 

 fish choose the one bank or the other. It is not impossible that con- 

 ditions at the base of the rapids tend to divert the major portion of 

 the run to one bank rather than to the other. In such a case the 

 results of leaving one bank unfished where the other is fished assidu- 

 ously will vary from those stated under the assumption that the run 

 is more or less equally divided between the two shores of the stream. 



Of course, it is possible that the bed of the stream, by virtue of the 

 large rocks in it, may have a more or less protected channel for the 

 passage of the fish. But even in this case, the current will necessarily 

 be more powerful along the bottom than it is at the sides near the 

 surface, and there seems to be no reason to think that in this particular 

 place conditions in the bed of the stream are exceptionally favorable 

 for the ascent of the salmon; and unless they are more favorable 

 than surface conditions would lead one to expect, salmon ^\dll hardly 

 be able to use that path. So far as could be ascertained, conditions 

 at the center, either in the surface or bottom waters, will be much the 

 same at all stages of the stream. On the other hand, shore condi- 



