PROGRESS IN BIOLOGICAL INQUIRIES, 1933 345 



their life cycle. The pink salmon that ai)pear in the first part of the 

 season are sexually immature and draw upon their stored energy 

 only for the purpose of maintenance during their migration to the 

 spawning grounds. As the season progresses, however, the salmon 

 composing the runs begin to show signs of sexual maturity while still 

 in the waters subject to the commercial fishery. Hence these salmon 

 draw upon their stored energy for maturing the sexual products as 

 well as for maintenance during their migration. It is owing to this 

 double drain upon their stored energy that the pink salmon entering 

 the connnercial catch during the latter i^art of the season are of 

 poorer quality. 



The percentage fat content and degree red coloration in the flesh 

 of the Pacific salmon have for years been used as a market standard 

 for quality. Hence, any information concerning the seasonal change 

 in these measures of quality in the pink salmon would be of value to 

 the cannerymen in grading their packs. It is for this reason that the 

 National Canners Association of Seattle cooperated with the Bureau 

 in a project aimed to determine the change in the percentage of fat 

 content and degree of red coloration in the pink salmon entering 

 Snake Creek at Olive Cove, Alaska, during the past summer. Ten 

 pink salmon were taken at random from the run each day during the 

 season. These fish w^ere first measured in order to estimate their 

 state of sexual maturity as indicated by their body form. A propor- 

 tionate cut was then taken from each fish and canned in a half pound 

 can. At the close of the season these canned samples were turned 

 over to the National Canners Association to be analyzed. Each 

 canned sample of fish bore the date it was taken and the sex of the 

 fish so that the chemical analysis will indicate the change in the 

 composition of both sexes throughout the season. The results from 

 the analysis of the change in the body form of the pink salmon show 

 that sexual maturity began to appear in the salmon at the beginning 

 of the third quarter of the season. The results from the chemical 

 analysis of the samples have not as yet been completed. 



The study of the racial characteristics of the pink salmon com- 

 posing the runs in Snake Creek and Anan Creek in southeastern 

 Alaska were continued during the past summer. The data col- 

 lected for this study during the past summer w^ll complete the 

 data necessary for the studj^ of the racial characteristics of the pink 

 salmon in these streams for two complete life cycles ; viz, the 1930-32 

 cycle and the 1931-33 cycle. The results from this study thus far 

 point very definitely to a racially distinct population in each stream. 

 There is also some indication that the even- and odd-year populations 

 in each stream are likewise distinctly different. The analysis of the 

 data collected this year will make it possible to draw definite con- 

 clusions in regard to the individuality of the odd- and even-year 

 populations in each stream. 



HERRING INVESTIGATION 



In December 1933 the herring investigation, under the direction 

 of Dr. George A. Rounsefell, assisted by Edwin H. Dahlgren, sub- 

 mitted to the Bureau a report on the races of herring in south- 

 eastern Alaska. The populations of herring were studied by 



