FORTY-FIRST HIEXNIAI. RKI'ORT 81 



STUDIES ON SPECIAL WATERS 



In addition to the foregoing snrveys to provide general information, 

 special studies were carried out on the following waters, not including 

 Wildlife Conservation Board Projects, which are discussed in a special 

 section of this report : 



Castle Lake, Siskiyou Couniy. The program at Castle Lak.- is .h-siKno.l to tiiul 

 out what species of trout should be planted in similar lakes, ami to studv ih- 

 costs of planting various species and sizes in terms of yield to the angler. 

 Sacramento River Test Stream, Siskiyou County. The present objective of this 

 investigation is to determine the efF.'ctiveness of phmtini.' fimi'Tling tn.iit in 

 similar streams. Marked hatchery trout are planted and th.- r.-lurns rh.'.k.-d b\ 

 creel census and electric shocking. Results to date show that a v.-rv smali 

 percentage of planted fingerlings reach a length of six inchi's. 



Klamath River Investigation, Siskiyou County. This program eonsist.s of a l..ng 

 range study of the factors affecting the survival of .salmonids in the Klnmath 

 River system. One year is being devoted to the study of each principal siippos.-.l 

 factor. 



Eagle Lake, Lassen County. This study was initiated to find ways t.. |)n'v<'nl 

 the extinction of the Eagle Lake trout and to restore trout fishing. 



Lake Almanor, Plumas County. The study of this lake was start fd in I'.Ml ic 

 determine causes for the reported poor trout i>rodiictiun mid t.. nifjisnrf ihi- 

 yield to the angler from plants of hatchery-reared fingerling trout. The study 

 was discontinued during the war, before any results could be obtained, but was 

 resumed in 1946 with the planting of marked trout fingerlinu's. Catch data arc 

 now being analyzed. 



Lake Tahoe Fishery Survey, Placer and El Dorado Counties. Field studies wen- 

 conducted on Lake Tahoe during the summer seasons of 1948 and 1!»49 by a 

 college graduate student employed as a Student Biologist, in partial fultiil- 

 ment of his requirements toward a Ph.D. degree. This work incindi-d sttidif.s 

 of the food and habits of the various species of fishes prt-scnt and nf ihi'ir 

 physical environment. 



Echo Lakes. El Dorado County. The very low trout catch despite heavy stocking 

 in these lakes has been the subject of a continuing investigation by the personnel 

 of District 3. Early in the bienniuni, limnological and population studies were 

 conducted and in the fall of 1949 a fish trap was constructed in the outlet. 

 Marked rainbow trout have been planted and it is hoped that recoveries of Inith 

 marked and unmarked fish in the trap will yield valuable information on losses 

 through the outlet. 



Clear Lake, Lake County. A detailed study of the fishes and fishery of Clear Ijike 

 was completed during the biennium. This work resulted in definitive reports on 

 the food of young black bass and on the life histories of the greaser bliicklish, 

 Sacramento perch, hitch, and Sacramento sfpiawfish. Of immedi;ite Interest was 

 an intensive study of the possible value of a closed season on warniwater fishes. 

 This study was done largely at Clear Lake, but drew upon datii from lUher 

 waters. The study concluded that there was no management value in a closed 

 season. The Clear Lake investigation also led to the conclusion thai the game 

 fish population could be increased if the forage fish supply was augmented. The 

 golden shiner was selected for introduction and a rearing pond was constructed 

 and stocked with shiners from San Diego County. A detailed study of the effect 

 of TDE on fish life and other aquatic organisms led to ^'commendations that 

 insured a minimum lo.ss to sport fishing when Clear J<ake was treated with this 

 chemical in 1949 to eliminate the Clear Lake gnat. 



Millerton Lake, Fresno/Madera Counties. An intensive study of the .Millerton 

 Lake warm-water fishery, as a typical example of the large fluctuating reservoirs 

 along the west .slope of the Sierra Nevada, was stjirted in 19J!t. rresenl evidence 

 indicates a lack of forage fish to be the main factor limiiing the fishery. At »he 

 request of sportsmen, and in an attempt to improve the defiriency of fo<M| for 

 bass, a subimpoundment in which to raise bluegill finu'erlincs was trii'<|, but 

 without appreciable success. 



