THIRTY-NINTH BIENNIAL REPORT 43 



•that there is nothing to be gained by demanding unreasonable releases 

 of water for fish protection, and of the 515 applications reviewed up to 

 June 30, 1946, only 27 have been protested. Of these protests, 14 have been 

 taken care of by including in the permit, provisions regarding mainte- 

 nance of stream flow ; by agreement between the applicant and the com- 

 mission ; by withdrawal of the application ; and by withdrawal of our 

 protest. Bight protests still were pending at the end of the period. In all 

 eases where the U. S. Fish and Wildlife Service and the U. S. Forest 

 Service were interested, cooperative contacts have been maintained with 

 these agencies. 



FISH SCREENS 



The maintenance of fish screens came under the jurisdiction of this 

 bureau on October 15, 1945, and operations of the fish screen crew in the 

 northern part of the State have since been under supervision of our 

 district biologist in that area. The installation of ^-inch by 3-inch mesh, 

 smaller than the mesh of most of our present screens, is being pushed, 

 since it is more efficient in preventing the loss of small fish and at the 

 same time clogs less easily than the larger mesh. 



FARM PONDS 



The number of small reservoirs constructed by ranch owners for 

 stock watering and irrigation purposes has greatly increased, and a 

 "farm pond" program is under way. This project includes not only the 

 furnishing of bass, sunfish and other warm-water species as initial seed 

 stock, but experiments at our Central Valleys Hatchery at Elk Grove 

 as to proper numbers and combinations of species for such waters, and 

 on weed control and fertilization. 



SHASTA RESERVOIR 



The proper fish management of the newly constructed Shasta Reser- 

 voir has been under study. A further problem in this connection has 

 arisen from the fact that ''hardheads" (Mylaphorodon conocephalus, 

 sometimes miscalled "pike") and other rough fish have migrated out 

 of this large body of water up its tributaries, especially the Sacramento 

 River, in such numbers as to endanger the heretofore excellent trout 

 fishing in these streams. Investigation indicates that the hardhead goes 

 upstream in the spring and descends again in the fall, and plans are 

 underway for the construction of a low dam on the Sacramento River 

 which will block future upstream incursions of these fish once the fall 

 migration has taken them downstream below it. It will include a trap 

 where trout on their upstream spawning migration can be segregated 

 from the rough fish and allowed to ascend, while the latter will be 

 destroyed. 



MISCELLANEOUS PROJECTS 



Other long-range projects which have been continued or revived 

 during the biennium are : The Lake Almanor study ; the Clear Lake inves- 

 tigation, to which one biologist is now devoting a large part of his time ; 

 diseases in the trout hatcheries ; pollution control, under one of our former 

 pollution specialists returned from naval service ; the AVaddell Creek 



