270 V. S. BUREAU OF FISHERIES 



mately 41 per cont of the total number being reds, 44 per cent pinks, 

 12 per cent chiuns, and 3 per cent cohos. Some of the tagging was 

 done during the early part of the season and some later, when the 

 run was at its maximum. Preliminary reports of recaptures showed 

 that the pinks and chums were taken almost exclusively in the lower 

 inlet from Kachemak Bay to Port Dick, while the reds were taken 

 in all parts of Cook Inlet where commercial fishing was permitted 

 and also at Montague Island, Port Etches, and Valdez Arm in 

 Prince William Sound, and in Uganik Bay on Kodiak Island. 



The Prince William Sound tagging operations were conducted in 

 nine experiments at five dift'erent localities during the early part, the 

 height, and the latter part of the season. Of the number of fish 

 tagged, approximately 97 per cent were pinks and the remainder 

 were largely chums. 



Complete returns on recaptures have not been received, but a 

 separate report on the work will be published. 



SALMON LIFE-HISTORY STUDIES 



Scientific investigations in connection with the life-history studies 

 of Pacific salmons were continued under the direction of Dr. Willis 

 H. Rich, who spent several weeks in the Karluk district during the 

 early part of the season, going thence to Prince William Sound, and 

 the southeast Alaska district. The scope of the work for 1929 was 

 extended to include the beginning of a detailed study of the red 

 salmon runs of Copper River and of the pink salmon of southeast 

 Alaska, the latter particularly to test the parent stream theory with 

 respect to this species. The investigation concerning the pink 

 salmon was carried on by Dr. Frederick A. Davidson, associate 

 aquatic biologist, formerly head of the zoology department of Beloit 

 College. Assistants of Doctor Rich in the study of the red salmon 

 runs were Seton H. Thompson in the Prince William Sound and Cook 

 Inlet areas, Merrill W. Brown at Karluk, and Harlan B. Holmes at 

 Chignik. Alan C. Taft was engaged at Stanford University, Calif, 

 in examination of scales and statistics of red salmon of Bristol Bay. 



Extensive collections of scales of red salmon were made in various 

 districts and a considerable number of pink salmon fry were collected 

 in southeast Alaska for scientific study. Approximately 50,000 

 young red salmon were marked at Karluk and a somewhat larger 

 number at Chignik. Reports of the investigations will be published 

 in separate documents. 



OBSERVATIONS ON THE ESCAPEMENT OF SALMON 



During the period of the salmon runs escapement conditions are 

 noted, and at the close of the season careful surveys of the spawning 

 grounds are made by bureau employees in all districts. If signs of 

 depletion are evident in any locality, or if it appears that less than the 

 required 50 per cent of the run has escaped for seeding the beds, 

 regulatory measures are revised accordingly in order that the yield 

 of the fisheries may be maintained at a maximum level. 



Southeast Alaska. — Although the run of pink salmon, the mainstay 

 of the industry in southeast Alaska, was considerably smaller than 

 in the preceding year, it was vastly greater than the run in 1927, 

 with which it may more pro])erly be compared, as that was the 



