PROGRESS IN BIOLOGICAL INQUIRIES, 1922. 3 



ber 17 the total escapement of red salmon up the river was 1,322,000. 

 The investigations in the Karluk region were most interesting and 

 profitable. Every spawning stream tributary to Karluk Lake was 

 examined, and upward of 1,000,000 red salmon were observed on the 

 very limited spawning grounds of that district. The escapement 

 for spawning as related to the commercial catch, a subject that the 

 bureau has under consideration at Karluk and Litnik in Alaska, as 

 well as at Quinault Lake and Baker Lake in Washington, is re- 

 ceiving merited attention from the fishing interests. It is the pur- 

 pose to continue the work in these fields and to extend the experi- 

 ments to other faA^orable streams. 



SALMON INVESTIGATIONS IN PACIFIC COAST STATES. 



The investigation of the salmon of the Pacific Coast States has 

 been continued by Willis H. Rich. Some additional returns of fish 

 were obtained during the fishing season of 1921 from the marking 

 experiments on the Columbia Eiver started in 1917, and it is ex- 

 pected that others will be taken during the season of 1922, although 

 none had been reported up to the end of the fiscal year. A state- 

 ment of the first results of these experiments is contained in the re- 

 port of the division for 1921. In continuation of the program on 

 the Columbia River two new experiments involving the marking of 

 approximately 100.000 young chinook salmon have been started. 



The study of the relative maturity of the chinook salmon taken 

 by troll and purse seine in the ocean along the Pacific coast has 

 been completed, and the report is in the final stages of preparation. 

 This will give in detail the data on Avhich the conclusions are based. 

 It has been found that the percentage of immature fish is very high 

 early in the fishing season, averaging about 90 per cent during 

 May and the early part of June. These figures apply particularly 

 to the fish taken off the mouth of the Columbia River, the region 

 that has received the most careful consideration. The percentage 

 of immature fish decreases as the season progresses, until in August 

 only about 20 per cent of the fish taken are immature. A similar 

 though less marked change occurs in the catches made in Monterey 

 Bay and off the coast of northern California. The report also in- 

 cludes data on the rate of growth of the salmon during their life 

 in the ocean. 



Knowledge of the general features of the life history of the 

 chinook salmon has been materially advanced by the study of the 

 fish taken in the open ocean. The data on the rate of growth during 

 the life in the sea are of especial importance, since they provide a 

 check on the results obtained from the measurements of the scales 

 of the mature fish taken in the river. The interjjretation of the 

 scales has received much attention, and most of the more important 

 difficulties in the way of the satisfactory determination of age and 

 other facts of the life history have been overcome. This phase of 

 the study has not been discussed in detail in the report on the 

 relative maturity of the fish taken in the ocean but is reserved for 

 inclusion with a future report on the general features of the life 

 history. 



