60 FISH AND GAME COMMISSION 



Clear Lake, Lake County, Investigation. Progress Report No. 1. Submitted 



September 27, 1946. 6 pp. 



Abstract: A report on the material gathered during the summer of 1946, 

 with recommendations for future investigatiuns. 



Observations on Conn Valley Reservoir, Napa County, on July 18 and 

 August 3, 194G. Submitted September 27, 1946. 8 pp., 5 photos, 1 map. 



Abstract: Thermocline at about 13 feet, with no O2 below. Water 75 degrees 

 and up above thermocline. RT concentrated in creek arms where water slightly 

 cooler. A research program for Conn "Valley Reservoir or Stevens Creek Reservoir 

 suggested and outlined. 



Notes on Hardhead Control in the East Fork of Russian River, Mendocino 

 County, California. Submitted November 17, 1947. 9 pp., map and 3 figs. 



Abstract: Described the drainage of Potter Valley, a series of erosion control 

 check dams in the valley, and the distribution of fishes in the waters. Apparently 

 Hardhead (Mylopharodon) are either present as resident, nonmigratory popula- 

 tions above a 7-foot 6-inch barrier or are able to surmount the obstacle during 

 their spawning migration. Additional studies to clarify this problem are suggested. 



The Fishery of Clear Lake, Lake County, California. Submitted March 15, 



1948. 60 pp., 10 figs.. Tables I-XXII, App. I, Exhibits A and B, App. II, Tables 



A-G. 



Abstract: General report on investigation of Clear Lake 1946-1947. Includes 

 descriptive material on Clear Lake, growth rate studies of important fishes, 

 analysis of the commercial and sport catch of Clear Lake, history of the fishery, 

 description of a closed season experiment, and a discussion of the rough fish 

 population of Clear Lake. * * * The populations of fishes in Clear Lake are in a 

 healthy condition and are not suffering from overfishing. The sport catch con- 

 sisting of 70 percent catfish, 10 percent LMB, 10 percent BCR, and 10 percent BG, 

 remained relatively stable 1936 to 1944. The 1946 catch was off about 40 percent, 

 apparently correlated with a decline of rough fish population, indicating that 

 game fish had decreased in numbers when their supply of forage decreased. * * * 

 Closed season experiment indicated that LMB will respond favorably to protec- 

 tion during spawning, in terms of numbers of young produced. * * * In order to 

 bring Clear Lake into full production, it will be necessary to increase the forage 

 fish supply. Differential protection applied to LMB should increase their per- 

 centage of the total population, probably at the expense of competing species such 

 as white catfish and crappie. 



MURPHY, Garth I., and CHANDLER, Harry P. 



The Effect of TDE on Fish and on the Plankton and Littoral Fauna in 

 Lower Blue Lake, Lake County, California. Submitted June 25, 1948. 33 pp., 

 2 figs. 



Abstract: Lake was treated by the Department of Agriculture with TDE 

 in a Xylene-Triton emulsion November 7, 1947, at the rate of 1 part to 45 million 

 to rid it of the Clear Lake gnat Chaoborus astictopus D & S. Daily samples of 

 water, plankton and lish were taken by Division of Fish and Game and other 

 observations made for five days before and seven days after the treatment with 

 an occasional sample during the next two months to determine the effect on fish 

 and fish food organisms. The insect and crusteacea fauna was so greatly reduced 

 that it is doubtful that the fish could maintain themselves. After six weeks some 

 species of crusteacea gained former numbers (not volume). Large numbers of 

 black crappie (the most abundant fish) were killed. Experiments were carried 

 out to determine the relative toxicity of different concentrations of various insecti- 

 cides on three species of fish. The gnat was apparently eliminated according to 

 U. S. Department of Agriculture report. 



SHAPOVALOV, Leo 



Report on Fisheries Resources in Connection With the Proposed Yolo- 

 Solano Project of the United States Bureau of Reclamation. Submitted July 5, 

 1946. 50 pp., incl. 20 photos, plus 1 map. 



Abstract: The proposed Yolo-Solano Project of the U. S. Bureau of Recla- 

 mation is a multiple-purpose feature of the Central Valley Project, providing 

 for irrigation, domestic water supply, power, salinity control, navigation, and 

 recreation benefits. In general, it involves (1) the storage of runoff waters from 

 Cache and Putah Creeks in Lake and Napa Counties, by means of three large 

 reservoirs and dams and (2) diversions from the Sacramento River at Knights 

 Landing and Lindsey Slough. Construction of reservoirs on tributaries of Clear 

 Lake is also being considered. 



The report describes the proposed project and existing conditions, prognos- 

 ticates changes in the fish populations and fisheries apt to result through the 

 construction of the project, and presents recommendations in regard to the con- 

 struction and operation of the proposed works which will insure the maximuin 

 development and utilization of the waters involved as sport fishing areas. 



Recommendations include initial heavy stocking of I^MB in Monticello Res- 

 ervoir and Putah Creek Rediversion Dam Reservoir, control of undesirable fish 

 species above site of Indian Valley Dam and subsequent stocking of RT in Indian 

 Valley Reservoir and screening and maintenance of flows where needed. 



