62 



PISII AND GAME COMMISSION 



Figure 2:j. Anglers on Rush Creek teat alreani, Mono County, May 2, ILi li 



10,000 LV trout planted, 8,881 (88.8 percent) were caught in 172 days of fishing; 

 7,020 of these were taken by July 31st. Unmarked fish contributed 13 percent 

 of total catch for 19 47 ; and 1,104 were browns, 214 rainbow, and 33 were eastern 

 brook. Average catch per angler hour for the season was 0.52. Per mile use of the 

 stream in 1947 is discussed. 



Report of Aquatic Plant Control at Twin Lakes, Mammoth, Mono Co., 

 California. Submitted December 8, 1947. 13 pp., 1 tbl., 6 figures (5 photos). 



Abstract : The two lower Twin Lakes over a period of years had become 

 obstructed by dense aquatic plant growth, chiefly Anacharis. The inain portion 

 of the center lake (12.7 acres) and the lower lake (9.4 acres) were each treated 

 with 700 pounds of sodium arsenite, with 7.5 percent arsenious oxide, mixed with 

 water and applied as spray. Effective initial concentration for the center lake 

 was 2.6 p. p.m. and 4.0 p.p.m. for the lower lake. Collapse of plant growth reopened 

 the entire 12.7 acres treated in the center lake nearly a month after treatment; 

 and by onset of winter freezeover two and one-half weeks after treatment in 

 the Icwer lake, 7.7 of the entire 9.4 acres had been reopened by similar collapse. 

 Fish loss was negligible. Since sodium arsenite will not control or eliminate 

 aquatic vegetation permanently, periodic treatment of the Twin Lakes, important 

 for angling and recreation, may be necessary. 



VESTAL, Elden H. and LEWIS, Robert C. 



Report on Airplane Fish-planting Tests in Mono County, California. 

 Submitted August 12, 1946. 8 pp. 



Abstract: Using division plane, tests were conducted with CT 50-ounce, 

 RT 10-ounce, 3-ounce, fl- to 8-pound, and with four brood fish from Hot Creek 

 Hatchery. Fish were dumped directly, dropped in containers with and without 

 lid, and in containers slung from a canopy cargo chute. Heights of release varied 

 from 25 feet to 1,000 feet, with most drops from 300 to about 450 feet. The aver- 

 age speed of the plane was about 100 miles per hour. Drops were made in the 

 mornmg from 7 to 11 a.m. Free-fall planting from 300 to 400 feet seemed to be 

 the most successful in the direct release scries. Fish from 50 to three ounces sur- 

 vived direct release better than larger fl.sh used. EB responded better than RT 

 Fish not immediately stunned swam for cover or deep water ; majority of fish 

 stunned recovered in two to five minutes. Predation (gulls) was high in first five 

 minutes after relea.se. Fish planted by direct relea.se of containers were mostly 

 killed or injured. Chute method was most successful of all tried — fish arriving 

 at impact area in excellent condition. Repetition of tests is recommended with 

 plane adapted for purpose, since some mortality resulted from fish striking sta- 

 bilizer and tail assembly of division plane. 



Report on the Second Airplane Fish-planting Tests in Mono County, Cali- 

 fornia. Submitted July 30, 1947. 8 pp., 1 table. 



Abstract: The second scries of airplane planting tests are described and 

 planting notes and observations are presented and discu.ssed. Free fall planting- 

 is con.sidered to be the method of choice for practical fl.sh planting in High Sierra 

 lakes. It is recommended that the Bureau of Fish Conservation proceed to have 

 designed and equipped a plane for fish planting in the High Sierras 



