PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1931 671 



tributions of brook, rainbow. Loch Leven and black-spotted trout totaled 

 1,326,800; and numbers of eggs, fry, and fingerlings were on hand at the end of 

 the year. 



YELLOWSTONE NATIONAL PARK (WYO.) SUBSTATION 

 [C. F. Culler and Fred J. Foster, in charge] 



The spawning season at the Yellowstone Park station in the summer of 1930 

 was a normal one in every respect. The crew reached Yellowstone Lake on May 

 13, and the station was closed for the season on September 13. Work began 

 under the direction of District Supervisor C. F. Culler. On July 1, with the 

 creation of the new Rocky Mountain region, the operations were transferred to 

 the supervision of District Supervisor Fred J. Foster. The new hatchery building, 

 which had been practically completed in the fall of 1929, was placed in commission 

 in June, 1930, and operated for the first time. The vast improvement over former 

 conditions was greatly appreciated by the station crew and also by the thousands 

 of visitors, who viewed the splendid new aquarium and the operations in the 

 hatching room from the raised balcony especially constructed for the purpose. 



During the year one concrete rearing pool, 60 feet long and 8 feet wide, was 

 constructed east of the new lake hatchery. It was connected with Hotel Creek 

 by 1,200 feet of 6-inch wood pipe, which was also tapped into the hatchery line 

 for emergency use. A building 80 feet long bj^ 22 feet wide was constructed for 

 the housing of a garage, a workshop, storage room, and food preparation room. 

 The three rearing pools west of the hatchery were completely reconstructed, and 

 a (luantity of debris and fallen timber was removed from around them. At 

 Mammoth Springs a log frame building, 12 feet by 20 feet in dimensions, was 

 constructed. It contains two rooms, one for food preparation and the other for 

 the storage of equipment. Five hundred feet of 12-inch wood pipe was installed 

 for bringing hot water to the rearing pools. 



One of the rangers of the National Park Service was detailed to cooperate in 

 the distribution of fish in the interest of park fishing conditions and rendered 

 excellent service by distributing from the Mammoth rearing pools a large number 

 of 13^-inch to 4-inch fingerling black-spotted. Loch Leven, and rainbow trout. 

 The superintendent of Yellowstone Park considers that the distribution accom- 

 plished during the season was the best that has ever been made in park waters. 



Increased demands for fish have been made from the surrounding region, par- 

 ticularly the Jackson Hole country; and increased distributions were made, 

 especiall}' to the national forests in this area. 



The collection of black-spotted trout eggs for the season numbered 15,389,000 

 or approximately 750,000 more than in the preceding year. Of this total 1,654,000 

 were collected from fish caught in trap nets, this constituting a new departure in 

 securing fish in Yellowstone Lake. Judging from the experience gained, it is 

 believed that this form of collecting fish will be of much importance in future years. 

 As the fish do not seem to ascend the stream in some years as well as in others, 

 the fishing of nets at various points in the lake may tend to off"set years of short 

 runs in the creeks. 



The Mammoth rearing pools were operated from July 10 to the close of 1930, 

 principally to determine the advisability of operating these pools through the 

 winter. It was found, however, that warm water from the Mammoth Hot 

 Springs was of sufficient quantity to operate not more than three pools and that 

 it was impracticable to mix the warm springs water with the summer supply 

 from Gardiner River without lowering the temperature to a point where the 

 growth of the fish would be greatly retarded. During the fall and spring when 

 ice was forming or breaking up in Gardiner River great difficulty was experienced 

 in maintaining an even temperature with the mixed river and spring water, as 

 the cold water supply would be checked by the ice formation, thus creating a 

 balance in favor of the warm water and sometimes causing temperature fluctua- 

 tions of 10 degrees within a half hour. Owing to these conditions it is not con- 

 sidered advisable to again operate the Mammoth rearing pools in the winter 

 months. 



SARATOGA (WYO.) STATION 



[S. M. AiNswoRTH, Superintendent] 



During the year a third electric wire was run from the electric plant in the 

 town of Saratoga to the station, to permit the installation of an electric motor to 

 furnish power for preparing fish food. The use of an additional hatching room 

 has greatly facilitated the handling of fry and fingerlings. All the hatching 



