362 U. S. BUREAU OF FISHERIES 



Yellowstone National Pakk (Wyo. ) Substation 

 [C. F. Culler, in charge] 



Coming as it does in the late spring and early summer months, the fish-cul- 

 tural work in this field covers portions of two fiscal years. At the beginning 

 of July, 1925, about 6,000,000 black-spotted trout eggs were being carried in 

 the hatchery, and the collections from that time to the close of the spawning 

 period on July 21 brought the season's total to 11,748.000, as opposed to the 

 collection of nearly 32,000,000 the preceding year. The principal cause for 

 this falling off in numbers is attributed to the unusually high water stages in 

 the streams and lakes and the abnormally low water temperatures, both of 

 these conditions resulting from the melting of vast quantities of snow in the 

 adjacent mountains. The low temperature in the open waters induced spawn- 

 ing in the much higher temperatures found on the beaches in the lakes. As an 

 offset to the shortage in numbers, the quality of all spawn taken was of a 

 high grade, the percentage of hatch being somewhat higher than that attained 

 in the work the previous year. 



As an experiment, 200 of the spawned-out fish were tagged before liberating 

 them in the streams where they were captured, the object being to ascertain 

 if they would return to the same streams to spawn in the succeeding year. 

 Close observations made up to the close of the fiscal year 1926 disclosed the 

 return of only three of the tagged individuals. 



Saratoga (Wyo.) Station 

 [S. M. Ainswokth, Superintendent] 



Fish-cultural operations in this field were limited to the propagation of the 

 brook, rainbow, and Loch Leven trouts, the combined output of which exceeded 

 that of the previous fiscal year by approximately 1,600,000. Considerable diffi- 

 culty was experienced in planting the stock of brook-trout fingerlings on hand 

 at the beginning of July, bad weather and nearly impassable roads, coupled 

 with inability to get into prompt communication with the Forest Service 

 employees who were to receive the fish, greatly retarding the distribution. 

 From the station brood stock of brook trout 131,000 eggs of excellent quality 

 were secured, the percentage of hatch exceeding 91. In the conduct of brook- 

 trout work in the Big Creek Lakes field a heavy storm occurring early in the 

 spawning season raised the water level of the upper lake so high that prac- 

 tically all of the brood fish in the traps were liberated, and before the traps 

 could be replaced the majority of the trout had passed into the second lake, 

 where they were inaccessible. Immediate steps taken to seine some of the 

 fish remaining in the vicinity of the trap site resulted in the capture of a 

 sufficient number to yield 403,000 eggs. 



Arrangements were made to enter the Lost Creek field for the collection of 

 eggs from wild rainbow trout during the last half of March, the weather being 

 warm at that time and indicating an early spawning season. Soon after 

 arriving on the ground, however, cold weather again set in and continued until 

 late in April. Esgs were obtained in this field from Lost Creek, Sage Creek, 

 and Canvon Creek between April 30 and May 26, the total number collected 

 during the season being 1,952,000. Of these. 1,153.000 were shipped, and from 

 the remainder 407.000 fry. representing 28 per cent of the stock brought to 

 the eyed stage, were liberated in parent streams. 



During the fall spawning season 318.000 Loch Leven trout eggs were obtained 

 from the station brood stock of 900 female fish, almost all of which were under 

 3 years of age. Of the resulting fry 111,000 were planted in public waters or 

 distributed to applicants, leaving about 159.000 on hand at the close of June. 



Spearfish (S. Dak.) Station 



[D. C. Booth, Superintendent] 



This station accomplished a considerable amount of work in the line of 

 pond construction during the year. Brood-trout ponds that were too shallow 

 for carrying large fish successfully were deepened; two of them were thrown 

 together* to form one large pond and were connected with the spring-water 

 supply from the hatchery, thus reducing the lower average of the water tem- 

 perature. A series of 11 concrete nursery ponds was constructed immediately 



