FORTY-FIRST BIENNIAL REPORT 97 



abandoned dams and other barriers, construction of fishways, and stock- 

 ing with hatchery fish. The activities of the biological staff in connec- 

 tion with these phases of the program are described elsewhere in the 

 report. ►Some of the important special fact-finding investigations carried 

 on during the biennium are summarized herewith. 



For some years the Bureau of Fish Conservation has carried out 

 counts of spawning steelhead and salmon at various stations. Such counts 

 provide a basis for legislative and management programs and for rec- 

 ommendations in connection with proposed large dams. In 1950, all 

 such work not already under the direction of the district biologists in 

 the respective districts was placed under their supervision. Listed below 

 are the counting stations operated by the Bureau of Fish Conservation : 

 Station Name of stream County River system 



Klamathon Racks Klamath River Siskiyou Ivlamath River 



Shasta Racks Shasta River Siskiyou Klamath River 



Sweasy Dam Mad River Humboldt Mad River 



Benbow Dam Eel River, S. Fk Humboldt Eel River 



On November 1, 1948, a graduate college student working as a stu- 

 dent biologist began a study of the efficiency of natural propagation of 

 our steelhead and salmon and the factors affecting it. This study is being 

 carried out in the Prairie Creek drainage, Humboldt County, and will 

 include two -winter seasons of field work. The first of these seasons was 

 that of 1948-49 and the second will be that of 1950-51. 



Another study which will in part complement the above was started 

 at Fall Creek, Siskiyou County, in 1949. In this study different numbers 

 of king salmon will be allowed to enter and spawn in Fall Creek each 

 year. The resulting offspring will then be counted on their downstream 

 migration to the Klamath River. From known numbers of parents and 

 known numbers of offspring we hope to determine the most effective 

 number of king salmon for a spawning tributary such as Fall Creek. 



The planting of steelhead in the Sacramento River from the federal 

 hatchery at Coleman was supervised by the biologist in charge of Dis- 

 trict 2. A number of these steelhead were tagged with celluloid disk 

 tags in an attempt to determine the return to the angler before and 

 after the fish had gone to sea. 



INLAND TROUT 



Although existing evidence indicates that the bulk of the trout 

 caught by anglers in California as a whole result from natural propaga- 

 tion, the hatcheries of the State play a very important role in supplying 

 fish to a number of waters which otherwise would be incapable of pro- 

 ducing satisfactory angling. 



In this program it is one of the principal functions of the biological 

 staff to make the necessary initial surveys of waters and then to check 

 them as necessary in order to keep stocking and general management 

 policies in line with existing conditions. The records and policies for 

 each managed water are kept current by means of a state-wide system 

 of "hatchery management binders." These are permanent records in 

 loose-leaf form, kept at each hatchery, with duplicate copies at the dis- 

 trict office, which show the essential survey data for the managed water, 



4 — 49247 



