REPORT OF THE COMMISSIONER OF FISHERIES. 11 



service. The Woods Hole (Mass.) laboratory was in operation witn 

 a small scientific staff in the summer of 1920, but it was impracticable 

 to reopen it in the summer of 1921. 



In the last annual report (pp. 22 and 62) reference was made to 

 the new building nearing completion at the Fairport (Iowa) station. 

 The building was occupied in August, 1920, and has been found ex- 

 cellently suited for the purposes of fishery investigations. On two 

 occasions during the year it was the scene of conferences of national 

 scope for consideration of questions affecting the conservation of 

 resources of interior waters and the application of scientific studies 

 to that end. Both conferences, but particularly the one held June 

 8-10, 1921, brought together persons of varied interests from many 

 States and were most heljjful in affecting interchange of ideas and 

 promoting harmonious action to the end that more care may be taken 

 to insure the permanency of fishery resources. 



PROPAGATION AND DISTRIBUTION OF FOOD FISHES. 

 OUTLINE OF THE WORK. 



The fisli-cultural activities of the Bureau are directed to the main- 

 tenance of the existing aquatic resources of the country and the de- 

 velopment of new sources of supply by the stocking of barren waters 

 and the introduction of useful species into waters to which they were 

 not indigenous. In this work the Federal Government operates 

 along the same lines and with the same object as do many of the 

 States. Five distinct functions are involved in this service, namely, 

 the collection and fertilization of the eggs of food fishes, the incuba- 

 tion of the eggs in hatcheries, the feeding and rearing of the young 

 of certain .species, the distribution of fishes (and, in some cases, 

 eggs) for planting in suitable waters, and the rescue of fishes from 

 landlocked flood waters of the Mississippi Valley. 



The principal source of the fish eggs handled by the Bureau con- 

 tinues to be the commercial fisheries, in which vast numbers of eggs 

 that would otherwise l)e sent to market in the fish and be a total loss 

 are obtained for hatching purposes by experienced spawn takers. In 

 the case of some important fishes, notably, but not exclusively, the 

 salmons of the Pacific coast, where commercial fishing does not ex- 

 tend to or is not permitted in 'the spawning areas, the ripe fish are 

 caught in seines or traps and their eggs are removed, the object 

 being to bring about a higher percentage of fertilization than is 

 possible under natural conditions and to afford to eggs and resulting 

 young protect i(m from enemies and physical fatalities during and 

 immediately after the hatching period. Eggs in noteworthy numbers 

 are obtained also from domesticated fish held from year to year in 

 ponds at the stations. 



No material increase in the scope and magnitude of the fish-cultural 

 work was possible during the year. With the available operating 

 funds remaining the same, the most careful scrutiny of expenditures 

 and the closest application of employees to their duties have been 

 required to maintain the service at its existing standard of efficiency. 



The fish-cultural operations in 1921 were conducted in 33 States, 

 Alaska, and the District of Columbia, and the output reached cxury 



