1400 BULLETIN OF THE BUREAU OF FISHERIES. 



artificial measures has been the perpetuation of the salmon supply that it is 

 believed the obliteration of the run and the wiping out of a long-established 

 fishery would ensue within five years after the suspension of fish-cultural opera- 

 tions. Physical conditions in the Penobscot have become so unfavorable for 

 the passage of salmon to the spawning grounds that natural reproduction is now 

 almost if not altogether inhibited; and the only noteworthy source of young 

 salmon is the eggs obtained by the Bureau from salmon purchased from the 

 fishermen. 



Evidence is not lacking to show that the long-continued and increasingly 

 extensive fish-cultural operations on the Great Lakes have prevented the deple- 

 tion of those waters in the face of the most exhausting lake fisheries in the world. 

 The luscious whitefish, the splendid lake trout, the excellent pike perch, or wall- 

 eyed pike, may be hatched in such numbers as to assure their preservation 

 without serious curtailment of the fisheries. The absence of concerted protective 

 measures, however, on the part of the various States interested has the tendency 

 to minimize the effects of cultivation and would seem to justify, if not impera- 

 tively demand, the assumption of jurisdiction by the Federal Government. 



The magnitude of the salmon fisheries of the Pacific States has required 

 very extensive artificial measures to keep up the supply. The operations of 

 the Bureau, in combination with those of the States, have been gradually 

 extended in both scale and scope until they have now attained a tremendous 

 extent and are addressed to all the species whose cultivation is as yet demanded. 

 The quantity of Pacific salmon eggs collected by the Bureau in 1908 was over 

 200,000,000, equivalent to 1,700 bushels. 



A remarkable fact in the history of the Pacific salmons — of which there are 

 five species — is that without exception all fish which enter any stream on the 

 entire coast die after once spawning, none surviving to return to the sea. This 

 wise provision of nature to prevent the overstocking of streams has been made 

 foolish by the appearance of man on the scene; he not only catches the salmon 

 in the coast waters and the lower courses of the rivers with gill nets, seines, and 

 pound nets, in the upper waters with the same appliances supplemented by the 

 fish wheels, and on the spawning grounds with all sorts of contrivances, but in 

 certain sections even carries his foolhardy greed to the extent of barricading 

 the streams so that no fish can reach the waters where their eggs must be depos- 

 ited. Natural reproduction, thus so seriously curtailed, is not sufficient to keep 

 up the supply in many of the streams where fishing is most active, for many of 

 the eggs escape fertilization, many more are eaten by the swarms of predaceous 

 fishes that haunt the spawning beds, and many are lost in various other ways 

 during the long hatching period; while the helpless fry and alevin fall a ready 

 prey to the same fishes in the upper waters and the young salmon have to run 



