11 -THE INVESTIGATION OF RIVERS AND LAKES WITH REFERENCE TO 



THE FISH ENVIRONMENT. 



BY BARTON W. EVERMANN, PH. D. 



It is the aim of this paper to call attention to the work of the U. S. Fish Com- 

 mission in connection with the study of the streams and lakes of the country. 



The Commission has always held that such investigations as it might properly 

 undertake should have as their ultimate object the discovery of facts and the attain- 

 ment of results which possess an economic value; and it is believed that all its inves- 

 tigations should be, conducted upon scientific methods. Most, perhaps all, investiga- 

 tions possess an economic value when their results and their relations come to be 

 properly understood. Rarely is the importance of any investigation fully compre- 

 hended at the time of its beginning. As every one knows, it is a matter of almost 

 daily occurrence that investigations begun as purely scientific studies are yielding 

 results of the greatest economic importance. 



So certainly is this true, and so firmly has this important fact become established, 

 that, in the proper conduct of any work undertaken by such a branch of the public; 

 service as the Fish Commission, it would seem that the investigations should be 

 comprehensive and thorough, and the method should be the scientific method, the 

 method which has yielded such brilliant results in other lines, the only method by 

 which definite progress is made. 



The U. S. Fish Commission is essentially and necessarily a scientific branch of the 

 Government. It was originally established by act of Congress February 9, 1871, for 

 the express purpose of conducting an inquiry into a scientific question where scientific 

 method was demanded, namely: "(1) An investigation into the cause of the decrease 

 of the sea-coast fishes and those of the rivers and lakes, with suggestions as to the 

 best methods of restoring the same; and (2) active measures looking toward the 

 propagation and multiplication of the useful food-fishes, either by restocking depleted 

 waters or by introducing desirable species into new localities." 



Thus it is seen that the Fish Commission began as a scientific inquiry whose 

 results, it was hoped, might redound to the good of mankind; and neither its true 

 purpose nor its method has changed. 



The problems which properly come within the scope of the Commission are among 

 the most intricate and difficult with which the biologist has to deal, and they are, as 

 individual problems, very numerous, although all more or less intimately related. 



For the sake of brevity, let us take it that the proper and ultimate purpose of the 

 Fish Commission is to increase the quantity and improve the quality of the fish food- 

 supply of the United States. 



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