42 



REPORT OP THE COMMISSIONER OF FISHERIES. 



The American rainbow trout was established in Europe many 

 years ago, and for a long time was one of the most successful fishes 

 for pond culture. Owing to continuous inbreeding, however, the 

 species eventually deteriorated to such an extent that its cultivation 

 was no longer profitable. The fishery authorities of various European 

 countries thereupon determined to introduce new stock, and, through 

 the usual diplomatic channels, made requests on the Bureau for small 

 lots of eggs. These shipments, together with two kinds of trout eggs 

 for governmental hatcheries in Japan and a lot of black "bass finger- 

 lings for Sweden, are shown in the following table: 



Shipments of Fish Eggs to Foreign Countries, Fiscal Year 1912. 



' Fingcrlings. 



WEST COAST HATCHERY WORK. 



Owing to low water in streams tributary to the Sacramento River, 

 and the consequent scarcity of fish in those streams, the collections of 

 salmon eggs for the California stations were about one-fourth less than 

 those of a year ago. Saloon were in the main river in somewhat 

 larger numbers than last season, but this slight increase is not con- 

 sidered to have any special significance, as the run of salmon in the 

 Sacramento lias shown a gradual decline for some years. This generaL 

 decline is attributed to several causes, chief of which are the large 

 losses of young fish by periodic overflows of the river and by their 

 ascent of the various irrigation ditches in operation. Contributing 

 causes are excessive fishing and the destruction of the fry ])y the rap- 

 idly hicreasing numbers of trout in the river. The obstacle of low 

 water was also encountered in connection with the rainbow trout work 

 at Hornbrook, Cal., reducing the egg collections at that point below 

 those of the preceding year, and at Derby Dam, on the Truckee River 

 in Nevada, where the propagation of the black-spotted trout was again 

 undertaken by the superintendent of the California stations. Trout 

 appeared in this river in large numbers in the spawning season, but 

 the majority remained in the deep pools in its lower reaches, where 

 they were inaccessible. Seining was resorted to but abandoned, 

 owing to the rough character of the river bottom, which caused the 

 nets to rise ami permitted the fish to escape. The few eggs secured 

 were turned over to the State officials and the station was closed. 



