FISH-CULTURAI. PRACTICES IN THE BUREAU OF FISHERIES. 



725 



By this means not onlv is a conservation effected but the Bureau is enabled 



to meet the great demand of applicants for the basses, sunfishes, and perches at 



a less sum than it would cost to produce them at a station maintained especially 



for their propagation. 



THE PACIFIC SALMONS. 



On the Pacific coast the Bureau has six permanent stations, including two in 

 Alaska, all of them maintained primarily for the propagation of the Pacific 

 salmons. Subsidiary to these there are six important field stations and other 

 smaller ones where salmon eggs are collected and hatched. An idea of the 

 extent of the work may be obtained from a statement of the output of these 

 stations during the fiscal year 1908. 



Output of the P.\cific S.'^lmons in 1908. 



The eggs shown in this table were transferred to state fish hatcheries and 

 other places for incubation. In California, as will be noted, a very large propor- 

 tion of the eggs taken are so distributed. 



Observations at various field stations indicate that a large percentage of 

 salmon eggs deposited naturally are fertilized but for various reasons only a 

 small percentage hatch. Modern fish-culture methods permit of a much higher 

 percentage of impregnation than under natural conditions, it being possible to 

 actually hatch and distribute as fry more than 95 per cent of all eggs collected. 

 So long, therefore, as a proper number of salmon are permitted to escape the 

 various fishing devices in their ascent to the natural spawning grounds, and it is 

 possible to capture them for the purpose of obtaining and impregnating their 

 eggs, perpetuation of the salmon fishery is assured. 



In the culture of the Pacific salmon it is impossible to save eggs from the 

 commercial catch, because the latter is made before the fish are ripe, and to 

 retain them until ripe is not feasible. By the time they have ascended the 

 rivers to the spawning grounds and are in condition for the fish culturist the 

 flesh has so deteriorated in quality that they are unfit for market in any form. 

 The Bureau must therefore itself capture the fish it requires, and this is usually 

 done by the construction of I:)arricades to intercept the run at the most suitable 

 point below the spawning grounds. 



