106 FISH AND GAME COMMISSION 



forage, and red-sided shiner and speckled dace as unutilized. Tables of stomach 

 sample analyses given for 8 species, including mackinaw trout, the principal preda- 

 ceous fish. Interrelationships noted include : rainbow-mackinaw, cutthroat- 

 mackinaw, brown trout-forage species. Historical account of fishery summarizes pos- 

 sible causes for disappearance of Lake Tahoe cutthroat. Natural reproduction ap- 

 pears to be perpetuating mackinaw and brown trout in the lake. Appendix (pp. 2'A- 

 27) partially discusses effects of season, wind, and temperature, with thermoclines 

 of two stations graphed. Table A (p. 25) breaks down the total sport catch logged 

 at one station (2,947 pounds for 131 days) into monthly data for mackinaw, rain- 

 bow% and brown trout, including: average weight per fish (4.25 pou;ids), average 

 number catches per day, and average number fish caught per day (5.4). Conclu- 

 sions expressed are tentative, pending final report. Bibliography of 9 titles. 



Outline of Work to Be Done on the Food Habits of the Forage Fishes of Lake 

 Tahoe in 1949. Submitted April 29, 1949. 8 pp. 



Abstract : Proposed study of Lake Tahoe ecology, with special emphasis on 

 food relationships of 5 species of forage fishes, is intended to reveal the kinds of 

 organisms utilized and their volumes. Seven sections outline the methods and pro- 

 cedures for sampling, size of samples, location of sample stations, and supplemental 

 observations proposed for determining : (1) food habits of 5 species of fish at 3 sta- 

 tions (by statistical analyses of stomachs), (2) seasonal dietary change, (3) food 

 habits of various sizes of a species, (4) diurnal variation in feeding and (5) inter- 

 relationships. Appendix lists equipment needed, its source, and estimated cost. 



Murphy, Garth I. 



Experiments on the Tolerance of Sacramento Perch to Copper Sulphate. 

 Submitted November 29, 1948. 3 pp. 



Abstract : A series of aquarium experiments indicate that Sacramento Perch 

 {Archoplites interrupt us) can stand copper sulphate in quantities up to 0.5 p. p.m. in 

 Clear Lake, Lake County, water (pH 7.8-8.1, total alkalinity 16 p. p.m.). 



The 1947 and 1948 Fishery of Conn Valley Reservoir, Napa County. Sub- 

 mitted January 11, 1949. 23 pp. 



Abstract : Conn Valley Reservoir, constructed in 1945, has a depth of 110 

 feet and a surface area of 950 acres when full. Ecological conditions in the lake are 

 bordei'line for rainbow trout. Rainbow trout and green sunfish are the principal con- 

 stituents of the lake population. In 1947, the catch consisted of 30 percent hatchery 

 trout planted at 25 to the ounce in April, 1945, and 70 percent wild trout. In 1948, 

 the catch was 96 percent catchable trout planted in March, 1948, and 4 percent wild 

 trout. Factors responsible for the lack of wild trout in the 1948 catch, and recom- 

 mendations for future management and research, are discussed. 



The 1948 Fishery of Clear Lake, Lake County. Submitted February 17, 

 1949. 13 pp., Appendix A, 2 figures. 



Abstract: In 1948, the catfishery was about one-third better than in 1947 

 in terms of catch per angler by number, apparently through the appearance of a 

 stronger year class (1947) in the fishery. A good forage fish crop was produced in 

 1948 and probably because of this survival of young bass, Sacramento perch, and 

 catfish to the early fall was exceptionally good. The outlook for an improving fishery 

 at Clear Lake is good. 



Fish tagging. Submitted March 16, 1950. 26 p. 



Abstract: This report is an annotated partial survey of the literature on fish 

 tagging. 110 papers are cited. 



Fish rescue and stream improvement work in the North Coast Area in 1949. 

 Submitted April 15, 1950. pp. 1-2, 7 tables. 



Abstract : In 1949 4 fish rescue crews were in operation. One was stationed 

 at Prairie Creek Hatchery, one in Humboldt County, and two in Mendocino County. 

 One of the Mendocino County crews was financed by Mendocino County. The four 

 crews combined rescued 783,313 trout and salmon. 



Returns from marked fall spawning rainbow trout planted in several Mendo- 

 cino County coastal streams in 1948. Submitted May 12, 1950. pp. 1-6, 4 tables. 



Abstract : 50,000 rainbow trout were planted in 9 streams, at approximately 

 6,000 to a stream. Plants were made in September and October. No serious effort was 

 made to obtain returns. Spot checks and reports from w'ardens and sportsmen re- 

 corded 8 of the marked fish in angler's catches in 1949. Reasons for the poor returns 

 are discussed. 



