REPORT OF THE COMMISSIONER OF FISHERIES. 41 



blackspotted trout from Yellowstone National Park. From these 

 epjrs 1.3G5>.()00 fry and fin«2:orlinf];s were hatched and planted in se- 

 lecteil waters in (rlacier Park. 



Until funds become available for the development of a number 

 of promising; outlyino: fields, the output of the Saratopi station 

 in u yomin<j: must be somewhat limited. Brood fish on hand pro- 

 duced durin"; the last fiscal year 90,000 e«2:^s of brook trout and 21)7,000 

 e<r^s of rainbow trout, while collections from Avild fish, made under 

 ditticult con(Htions, yieldeil 81.000 e<r^s of brook trout and 408,750 

 e^<rs of rainbow trout. The hatchery supply was augmented by 

 430,000 e<rirs of blackspotted trout and 406,000 eggs of brook trout 

 from other stations. 



At the Springville (Utah) hatchery the brook rainbow and black- 

 spotted trout have remained in excellent condition, but the eastern 

 brook trout have deteriorated. Fish Lake continues to be the most 

 prolific source of eggs. The lake is operated jointly by the Bureau 

 and the State game and fish department, and the Bureau's share of 

 the collections in 1920 was 1,035,000 brook-trout eggs and 1,330,000 

 rainbow-trout eggs. Special attention is being given to the main- 

 tenance of the fish supply in Fish Lake, as its value as a source of 

 eggs is recognized. 



The work of the Leadville hatchery and its field stations in Colo- 

 rado was quite successful, especially as regards the propagation of 

 eastern brook trout, of which 5,909,900 eggs were obtained by parties 

 stationed on eight lakes. In an attempt to develop a new field station 

 for collecting eggs of rainbow and blackspotted trouts at Antero 

 Eeservoir, two apprentice fish-culturists detailed to make investiga- 

 tions and locate spawning grounds were mj^^steriously drowned. 



Owing to lack of suitable help and to the abnoiTnally large expense 

 that would have been reciuired, no attempt was made at the Spear- 

 fish (S. Dak.) station to obtain eggs from wild fish as hereto- 

 fore. Brood stock held at the hatchery produced 107,000 eggs of 

 eastern brook trout and 130.000 eggs of rainbow trout, which were 

 supplemented by 947,000 eggs of brook trout purchased from dealers 

 and by the transfer from other fields of 419,000 eggs of blackspot- 

 ted trout and 25,000 eggs of lake trout. The water supply at this 

 station has long been unsatisfactory and at times precarious. During 

 the protracted winter of 1919-20, the flow of water was at one 

 time reduced to 22 gallons per minute for all hatchery purposes, and 

 three 12-foot troughs each containing from 25,000 to 40,000 eyed trout 

 eggs were given only 21 gallons per minute, which amount was not 

 increased and the numbers of eggs and fry were not reduced until 

 the feeding stage was reached. By an agreement recently made 

 Avith the municipal authorities of Spearfish, the Bureau is to have the 

 use of the overflow from the newly constructed city reservoir. By 

 means of a separate pipe line, water of desirable quality will become 

 available without cost, and for the first time the hatchery and ponds 

 will have an adequate supply for present and prospective needs. 



In the Xew England trout hatcheries there was a serious epidemic, 

 which greatly curtailed the production of brook trout. At the Berk- 

 shire hatchery the malady, known as the " white-spot " disease, was 

 particularly severe and reduced the output to insignificant propor- 

 tions. Even under favorable conditions the yield of brook trout at 



