First fish arrived on May 21. Of the season's 

 total of 107 fish, 99 were reported as jacks, 

 2 were females, and the remainder mature 

 males. Of the 107 fish entering the pond, 

 2 fish (1.7 percent) died prior to spawning. 

 In this same year, 184 fish were held in the 

 dirt pond and losses were 25 fish (13.6 per- 

 cent). 



In 1960, first spring chinook salmon entering 

 the concrete pond at Carson hatchery arrived 

 on May 5. Shortly thereafter areas of fungus 

 were observed on some of the fish. To retard 

 further development of fungus, the fish in the 

 concrete pond were treated with malachite 

 green at the rate of 1 : 1,000,000 on the 

 following dates: July 27, August 5, 8, 10, 12, 

 15, 22, 24, and 26. Observations indicated that 

 development of fungus was apparently checked, 

 and in some cases the infected areas healed 

 over. In all, 552 salmon entered the concrete 

 pond (table 5). Of the 552 fish, 331 were 

 females, 170 males, and 51 jacks. Daily 

 mortalities are given in Appendix table A- 8. 



Spawning of fish held in the concrete pond in 

 1960 began on August 4, as compared to 

 August 8 of those held in the dirt pond. Ter- 

 mination of egg taking from adults in the 

 concrete pond occurred on September 22, and 



in the dirt pond onSeptember 27. On August 29, 

 1960, 47 male and 17 female spring chinook 

 salmon were hauled from Little White Salmon 

 hatchery and placed in the concrete holding 

 pond at Carson hatchery. Mixing these two 

 groups of fish together prevented keeping a 

 separate record of those fish swimming into 

 the pond. Total losses occurring during the 

 holding period amounted to 13.4 percent as 

 compared to 13.7 percent in the dirt pond. 



Information regarding incubation of eggs and 

 fingerlings reared is given in table 6. 



Mortalities occurring during ripening period 

 of those salmon which swam into the concrete 

 pond at Carson hatchery in 1961 are given 

 in table 5. First fish entered the pond on 

 May 10, as compared to May 5, 1960. Spawning 

 began on August 16 and ended September 16. 

 In all, 141 females, 142 males, and 326 jacks 

 appeared at the hatchery in 1961. Losses 

 amounted to 10.3 percent as compared to 6.8 

 percent in the dirt pond. Daily mortalities in 

 the concrete holding pond are given in Appen- 

 dix table A-9. Slightly higher water tempera- 

 tures occurred in the concrete pond than in the 

 dirt pond in 1961. This may or may not be the 

 reason for the difference in losses of fish. As 

 in 1960, it was necessary to treat the fish with 

 malachite green to retard fungus development. 



Table 6. — Losses incurred during artificial rearing of spring chinook salmon resulting from 

 spawning of adults held in concrete holding pond, Carson National Fish Hatchery, 1957, 

 1959-61. 



""" Efegs taken were included in spawning operations in dirt holding pond. 



^ Of 107 adults returning to concrete holding pond in 1959, 2 were females and both died prior 

 to spawning. 



^ Includes eggs taken from fish transferred from Little White Salmon hatchery. 

 ^ Fish to be released in spring of 1963. 



