230 The Life Story of the Fish 



local interests which profit from dam construction no mat- 

 ter what the over-all effect. That many of these projects have 

 unquestioned merit in no way gainsays the truth of this state- 

 ment. If, in the future, man learns to harness atomic power 

 to domestic and industrial machinery, water will no longer 

 be needed for hydroelectric plants j and if he learns to do 

 what the simplest blade of grass can, namely, to produce the 

 chlorophyl in whose presence carbon dioxide and water react 

 to form food, water will no longer be needed for irrigation. 

 Man's only need for water will then be to drink and to wash 

 with, the dam-building agencies will presumably cease to 

 exist, and the atomic and chlorophyl agencies which succeed 

 them will probably not interfere with the habits of the 

 salmon — if by that time any are left. 



In the early days the dam-building agencies paid little 

 attention to fish, and their work at times resulted in the 

 large-scale destruction of creatures which another set of agen- 

 cies was hard at work trying to conserve. All this has now 

 been changed. The dam-builders are now required by law 

 to consult with the fish-conservers and to include in their 

 projects in so far as practicable the fish-saving measures rec- 

 ommended by the latter. One of the first and most widely 

 publicized of these co-operative labors was the Bonneville 

 Dam. This barrier lies 140 miles from the mouth of the 

 Columbia, but above it the river stretches its winding chan- 

 nel back into the continent for 1,100 miles more, partly in 

 the United States and partly in Canada, and it is in the 

 waters above the dam site that the major part of the im- 

 mensely valuable salmon run finds its spawning-beds. Not 

 only do greater numbers go above the dam, but individual 

 fish in this part of the run are commercially more valuable 

 because, having the furthest distance to go to the spawning 

 grounds, they run earlier and carry a much larger reserve of 

 fat than those which spawn near the sea. That means could 



