46 REPORT OF THE COMMISSIONER OF FISHERIES. 



water often becomes warm, stagnant, and unfit for trout or other 

 desirable species. In some states the destruction of fish life from 

 these causes has already become serious and is generally deprecated. 

 Much of the loss might be averted by placing a simple and inexpensive 

 device — such as a paddle wheel or screen — at the head of ditches so 

 that fishes would be frightened away from the intake or prevented 

 from entering it. The general state superintendent of fish hatcheries 

 for Colorado reports that unless laws are enacted requiring the placing 

 of screens or wheels in the irrigation ditches the fishing industry- 

 of that state will be seriously imperiled; and similar testimony has 

 come from well-informed persons in Montana and other states. In the 

 event of the failure of the state legislatures to afford effective and 

 prompt relief, a general federal law, applicable to all waters for the 

 utilization of which the government has given aid, may become 

 necessary. 



Respectfully, George M. Bowers, 



Commissioner. 

 The Secretary of Commerce and Labor. 



O 



