112 American Fisheries Society 



Of special interest to the conservationist and fish culturist 

 are annual canvasses of the shad fishery of the Hudson River 

 begun in 1914, and the shad and alewife fishery of the Potomac 

 River initiated in 1919. In the former stream the rehabilita- 

 tion of the fishery depends upon natural reproduction and local 

 protective measures, and in the latter material aid is being 

 given these agencies through extensive fish cultural operations. 

 It is hoped that by conducting such canvasses annually over 

 an extended period of years, informative data of considerable 

 value may be secured. 



CONCLUSION 



In this brief statement mention has been made of some of 

 the important functions of the Division of Fishery Industries 

 and of some of its efforts in each field to render the commercial 

 fisheries the aid they so richly merit. In conclusion I wish to 

 emphasize the close interrelationship of its activities, which 

 have been very properly correlated in one place, and the close 

 relationship with the work of other divisions in this branch 

 of the service. In the Bureau of Fisheries, there is working 

 side by side with the Division of Fishery Industries, a division 

 devoted to the biology of fishes — their habits, food, mi- 

 grations and interrelations — which serves as an ever-present 

 check on the increasing efificiency of exploitation. It tells us 

 that the life in the waters is communal, and that interference 

 not carefully restrained, may upset the balance in the waters; 

 that sound biology and regard for the future forbid us to take 

 unlimited advantage of everything we know about exploiting 

 fisheries. There are, for example, known methods of taking 

 fish more efficient than many of those in legitimate use, but 

 sound policy requires that such methods be discouraged. Thus, 

 the work of exploitation must be governed not only by the 

 needs of the trade, but by the needs of the community of ani- 

 mals in the water. Species such as sharks, gars, and the bow- 

 fin, that appear injurious and destructive to the whole com- 

 munity of fishes, are receiving particular attention in prefer- 



