ALASKL\ FISHEEY AND FUR-SEAL INDUSTRIES, 1935 17 



pink salmon through Clarence Strait. Nineteen hundred pink salmon 

 were tagged during closed periods from July 27 to August 17, inclu- 

 sive, all the work being done at the McLean Arm trap of the Alaska 

 Pacific Salmon Co. Leroy S. Christey, temporary assistant, per- 

 formed the tagging operations, under the direction of Dr. Frederick 

 A. Davidson. The patrol vessel Kittiwake and later the Scoter 

 were detailed to assist wath the undertaking. A reward of 25 cents 

 each was paid for the return of tags from the marked fish accom- 

 panied by information as to the time and place of recapture. The 

 returns amounted to more than 33 percent of the total number of tags 

 placed on the fish. 



It is planned to conduct a similar experiment in Clarence Strait in 

 1936 to detei-mine any differences in the migrations of the pink 

 salmon runs in the even and odd years. 



SALMON LIFE-HISTORY STUDIES 



Studies of the life histories and fiuctuations in the abundance of 

 the Pacific salmon in Alaska were continued in 1935 by the staff of 

 the Fisheries Biological Station at Seattle, Wash. These studies are 

 of necessity confined to definite localities, but it is felt that the in- 

 formation secured from them is in general applicable to the same 

 species in all parts of the Territory. A major investigation dealing 

 with the red salmon was conducted at Karluk, and one pertaining to 

 the pink salmon was carried on at Little Port Walter, Biological 

 data on the red salmon runs were also collected in the Bristol Bay, 

 Chignik, and Copper River areas. 



Salmon-counting weirs maintained at Karluk and Little Port 

 Walter furnished data regarding the number of adults returning to 

 the streams to spawn. The results from the studies at these twO' 

 locations, together \vith information collected at various points 

 throughout the Territory, indicate that the changes in natural con- 

 ditions under which the young develop greatly influence the abun- 

 dance of salmon. Efforts are being made to evaluate these natural 

 factors in order to provide information relative to the probable 

 abundance of each year's runs. 



An investigation dealing with daily catch records of the principal 

 types of fishing gear in the various fishing areas throughout Alaska 

 was started during 1935, the primary aim of which is to secure in- 

 formation concerning the yearly fluctuations in the abundance and 

 time of appearance of the salmon runs in each area. Information on 

 these fluctuations, which are due to natural as well as artificial causes, 

 is of importance in determining proper regulations for the conserva- 

 tion of the runs. 



Studies dealing with the biological changes that take place witliin 

 the pink salmon during the spawning migration and affect the quality 

 of the commercial pack were continued during the year, in coopera- 

 tion with the Seattle branch of the National Canners' Association. 

 A preliminary report, entitled "Physical and chemical changes in the 

 pink salmon during the spawning migration", has been prepared for 

 publication as Investigational Report No. 33, by Frederick A. David- 

 son and O. Eugene Shostrom. 



