2 KEPORT OF THE COMMISSIONER OF FISHERIES. 



has been given to the rearing of important species wherever practi- 

 cable, and the output of adult, yearling, and fingerling fish was nearly 

 50 per cent larger than in any previous year. 



The importance of the Bureau's fish-cultural operations, however, 

 must not be gauged b}^ the results during any one year, but Iw the 

 average for a series of years. Peculiar seasonal conditions often 

 material!}" modify the work of particular stations, sometimes favor- 

 abl}', more often unfavorably', and give an erroneous impression as to 

 its extent. It usually transpires that a year which is characterized 

 by a greatly diminished yield of certain fishes is noteworthy for an 

 augmented output of others, so that the aggregate distributions 

 remain normal. This point, which has frequently been emphasized 

 and illustrated in previous reports, was exemplified anew in 1904,. when 

 an exceedingly poor season for shad and white-fish was offset b}" the 

 largest collections of eggs of Pacific salmons and flat-fish ever known. 



An important feature of the work of artificial propagation, which 

 has often been referred to but can not be too strongly emphasized, is 

 that. an exceedingly large percentage of the young fish hatched annu- 

 ally are from eggs taken from fish that have been caught for market, 

 and hence would be totally lost were it not for the efforts of the 

 Bureau. To the many hundred millions of young food and game 

 fishes thus produced must be added many more millions resulting from 

 the superiority of artificial propagation over natural propagation in 

 the matters of fertilizing and incubating eggs and of safety of the 

 young. 



STATIONS OPERATED. 



The fish-cuitural work of the Bureau in lOOi was conducted in 26 

 states, at 40 stations and substations. In respect to their output, the 

 substations are in most cases of equal, in some cases of greater, impor- 

 tance than the stations, but their equipment is less complete and for 

 administrative purposes they are subordinated, and their personnel 

 supplied from the stations to which they are attached. 



The demand and the local facilities determine the proportion of 

 effort directed toward the cultivation of the important commercial 

 species. During the past jeav the salmons were propagated at 11 

 stations; white-fish at 7; lake trout at .5; shad at 4; pike perch at 3; 

 cod at 2; flat-fish at 2; striped bass, white perch, and yellow perch at 

 1 each; and the lobster at 2. 



THE SPECIES CULTIVATED AND DISTRIBUTED. 



The number of species now regularly cultivated and distributed by the 

 Bureau is upward of 50, and the artificial propagation of new fishes is 

 being taken up as the work increases and the demand arises. A full list 

 of the species handled in 1904 follows, from which it will be seen that in 

 every section, so far as the existence of hatcheries permits, the su pplj'^ of 

 the important food and game fishes is being increased by the Bureau's 



