392 U. S. BUEEAU OF FISHEEIES 



of the e3sential data required for developing a stocking program 

 for each body of water is given in tabulated form, accompanied by 

 stocking recommendations. 



STREAM IMPROVEMENT IN CONNECTION WITH THE STREAM SURVEYS 



Extensive work in stream improvement was carried on in the 

 .national forests in cooperation with the Forest Service. Except 

 in a few instances, the work was done by C. C. C. labor under the 

 supervision of men employed by the Bureau. Since there are few 

 reliable data on which to base an estimate of the true value of gtream 

 improvement the work was primarily experimental. 



It is evident that the nature of improvements which will prove 

 •of most value will vary widely with conditions and for that reason 

 stream conditioning was carried on in as many different types of 

 streams as jDOSsible. Very little work has been done heretofore on 

 swift, mountain streams such as are found in the great majority of 

 the national forests. Such streams are obviously more difficult to 

 work with than sluggish, meadow streams which have been the type 

 on which most improvement work has been done in the past. In 

 some instances streams were selected for improvement that offered 

 most serious obstacles to permanent installations for the purpose 

 of subjecting the devices to the most rigorous tests. Preliminary 

 reports indicate that most of these installations have witlistood the 

 •effects of exceptionally heavy floods with little damage. 



At the conclusion of the summer's work a memorandum was pre- 

 pared on " Methods for the Improvements of Streams." This memo- 

 randum contains a discussion of the principles of stream improve- 

 ment and detailed descriptions of the devices which have been 

 found to be of greatest value. 



INVESTIGATIONS IN THE ROCKY MOUNTAIN REGIONS IN THE 

 INTEREST OF FISH STOCKING 



The Bureau's investigations in this region by Dr. A. S. Hazzard 

 are almost solely directed toward the betterment of sport fishing. 

 'Commercial fishing at present is restricted to the taking of whitefish 

 in certain States and to limited sucker and carp fisheries in others. 

 Angling (principally for trout) is becoming increasingly popular with 

 the resident and tourist, while in the majority of areas the fishing is 

 rapidly deteriorating. The rapid development of new roads and 

 trails and the accompanying increase in angling have necessitated 

 -extensive stocking and environmental improvement. 



Investigations during the past 4 years have demonstrated the need 

 for intensive studies of the life histories of the principal native game 

 and forage fish in order to determine their requirements. Such 

 studies should indicate the types of waters to which they are best 

 suited and how their environment can be improved. Similar studies 

 -of so-called " obnoxious " fishes such as the chub, bony-tail squaw- 

 fish, and sculpin are also necessary in order to learn the extent of 

 their competition with game fishes or their unsuspected value to 

 these fishes. This information is necessary before intelligent efforts 

 toward control can be made, if such control proves desirable. 



