A NATIONAL PLAN FOR AMERICAN FORESTRY 1567 



balance is often critical. Research in both animal and bird life is 

 constantly revealing new facts, the use of which is invaluable in form- 

 ulating policies of forest and game management. 



The program of biological research for the immediate future con- 

 templates the carrying out of the provision covering this subject in 

 the McSweeney-McNary Act, making available increasing annual 

 appropriations which will reach the amount of $150,000 in the fiscal 

 year 1938. The act provides that annual appropriations may be 

 made thereafter of the size necessary to carry out the provisions of 

 the act for biological investigations. 



FISHERY RESEARCH IN FOREST WATERS BY THE BUREAU OF 



FISHERIES 



The importance of fish as a forest resource, to be maintained and 

 improved for public benefit, has been discussed at length in the sub- 

 section ''Fishery Management in Forest Waters of the United States". 

 So many technical problems are involved in establishing any compre- 

 hensive program of fishery management of forest areas that scientific 

 research is essential. This research is conducted by the Bureau of 

 Fisheries. 



This research, outlined in more detail in the section above referred 

 to, includes, first, a physical assessment of forest areas from the point 

 of view of water resources, fish populations, and the demands made 

 upon the natural supplies of fish by fishermen. Many factors enter 

 into this physical assessment, such as the location and dimensions of 

 streams and lakes, the flow of streams and their seasonal fluctuations, 

 the character of stream beds, the extent of ripples and pools, the 

 physiography of watersheds, and the chemical composition and 

 thermal relations of water. Reasonably complete information is 

 necessary also as to the kinds and quantities of organisms present in 

 the water or on adjacent land that are available as food for fish. A 

 further requirement is an inventory of existing fish populations, in- 

 volving determination of the numerical relation between different 

 kinds of fish, as a basis for determining the maximum number of 

 food fishes of the most desirable or useful sizes that can be produced 

 on a given area. 



The existing or potential demands upon the supply of fish cannot 

 now be determined satisfactorily because the facilities for doing this 

 are very inadequate. A complete program of fisheries management 

 should include the furnishing of such figures not only to determine 

 the need for additional production but to provide a more accurate 

 check upon the success of methods to increase the yields. 



More extensive studies are needed of the ecological requirements 

 of fish to be planted. These involve controlled experiments to deter- 

 mine means of augmenting the food supply, the value of various 

 foods, the effect of competing species upon each other, proper levels 

 of stocking intensity, the migratory and breeding habits of various 

 species, and the general effects of individual systems of management. 



Closely associated with the ecological investigations are laboratory 

 studies for the purpose of improving hatchery technique. Notable 

 progress has been made by the Bureau of Fisheries in certain direc- 

 tions through such studies during the past few years, but much 

 remains to be done. 



