PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1923. 59 



Springville (Utah) and Leadville (Colo.) stations. From these 

 eggs, together with 90,000 collected from brood trout in the station 

 ponds, 1,271,000 fry Were hatched, or nearly 92^ per cent of the 

 original stock. Quite heavy losses occurred during the spring, due 

 principally to (lie impossibility of securing fresh supplies of liver 

 at all times. Notwithstanding this difficulty the output of brook 

 trout exceeded 9()0.O()0, about two-thirds of them being tingerlings, 

 and nearly 500,000 were on hand at the close of the year. 



This station also received 1,450,000 black-spotted-trout eggs from 

 collections made in the Yellowstone National Park, 338,000 rainbow- 

 trout eggs from its Meadow Creek auxiliary, 75,000 lake-trout eggs 

 from the Duluth (Minn.) station, and 58,000* steelhead eggs from 

 Oregon. Of this stock eyed eggs of the rainbow and black-spotted 

 trouts to the number of 150.000 were reshipped to applicants. The 

 remainder was developed with not more than normal losses, fur- 

 nishing an aggregate output of 981,600 fingerlings and fry and 

 leaving on hand, at the close of the year a material percentage of 

 the original number to be reared to a larger size before distributing. 



Quite extensive alterations were made to the ponds at Bozeman 

 station during the year with the view of eventually reconstructing 

 the entire system as funds permit. In pursuance of a carefully 

 devised plan ponds Nos. 1 to 18, located in swampy ground, were 

 converted into six rock and gravel-bottom Enclosures, each approxi- 

 mately 90 feet long, 81 feet deep, and 4 feet 7 inches wide at the 

 bottom, with a slope sufficient to give a width of 5 feet 7 inches at 

 the top. These ponds are so arranged that when their dams are 

 drawn all bottom sediment is swept by the heavy current toward 

 the lower end, assisting very materially in cleaning operations. 

 Screens extend across the entire pond areas and the outlet boxes 

 in the sides are fitted with both screens and dams. It is intended 

 later to lengthen these ponds to approximately 175 feet by throwing 

 into them the space now occupied by the remaining 18 ponds of the 

 old series. Each of the six ponds will then be provided with full- 

 width dams and screens to form two or more inclosures at will, in 

 accordance with the needs of the work. When the entire nursery 

 system has been reconstructed the available supply of spring and 

 creek water will be arranged to flow through the entire length of the 

 ponds. 



MEADOW CREEK (MONT.) SUBSTATION. 



Rainbow trout operations at the Meadow Creek substation were 

 greatly obstructed by the preparations being made by the Montana 

 Power Co. to build a bridge across the stream. In connection with 

 this project the water level in the creek was maintained at so low a 

 level throughout the entire spring that many of the ascending trout 

 were forced to turn back and seek spawning grounds elsewdiere. 

 Egg collections were therefore curtailed, the total amounting to 

 only 1,520.000. The spawning season was from two to three weeks 

 shorter than the average, extending only from April 23 to the end 

 of May, and the losses of eggs were unusually heavy, only 810,000 

 or 54 per cent oi the collection surviving to the eyed stage. Three 

 hundred thousand of the eyed eggs were hatched at the substation 

 with the view of returning the product as fingerling fish to the home 



