PROGRESS IN BIOLOGICAL INQUIRIES, 193 3 343 



iirst was prosuinod that tho seaward ini<2;rati<)n at Chiji^nik extended 

 for the 5 months. As it was realized that such a lon<j^ nii<^ration 

 period woiUd result in scale characters that would be conl"usin<^ in 

 age determination from the adult scale, 65,000 of the jn-esumed 

 migrants were marked in li)21). The marking was divided into three 

 lots, the fish in each lot being distinctively marked. The first lot 

 represented fish caught between May lil> and July 4; the second lot 

 from July 11 to July "24; the third from August IG to August 2(). 



The mature fish from tliis marking, Avhich returned to spawn dur- 

 ing 1932 and 1933^ have added interesting anda valuable information 

 to our knowledge of their life and habits. Among the returns from 

 the first lot G7 percent continued on to the ocean during the year in 

 which the}" were marked, whereas the remaining 33 percent lingered 

 an additional year in fresh water. Of the second lot only 4 percent 

 migrated during the year of marking and 9G percent remained in 

 fresh water for an additional year. In the third lot only 3 percent 

 migrated and 97 percent remained for another year. These observa- 

 tions indicate that the seaward migration is confined essentially to 

 the early part of the season and that for the remainder of the season 

 the fingerlings found in the river — even down to the entrance of the 

 estuary — must return to the lake before winter. Preliminary returns 

 from marking in 1930 and 1931 confirm these findings and indicate 

 that this peculiar habit is a regular occurrence. 



BRISTOL BAY RED-SALMON INVESTIGATION 



Although funds were not available for a biologist to carry on 

 field w^ork in Bristol Bay during the past year, scales of the 1933 

 red-salmon populations in this area were secured through the co- 

 operation of the Alaska Division of the Bureau. Scale samples and 

 body measurements of the red salmon composing the runs in Bristol 

 Bay have been accumulating for a number of years. These data 

 were studied by Dr. Frances N. Clark at Stanford University during 

 the past year. Dr. Clark analyzed the data from the Nushagak area 

 of Bristol Bay, and included in a report the results of this analysis 

 together with recommendations for future investigations in this area. 

 This report, " Ked salmon in Nushagak district, Bristol Bay ", is now 

 on file in the Washington office. 



PUGET SOUND SOCKEYE INVESTIGATION 



The stud}' of the fluctuations in abundance of sockeye salmon of 

 Puget Sound in the State of Washington w\as continued during the 

 past year, under the direction of J. A. Craig. For the purpose of 

 this investigation, a statistical study has been made of the catch 

 return of a constant unit of gear fished during a constant period of 

 time. 



Total catch or pack records arc often inaccurate and at times even 

 misleading wdien used for the purpose of judging the relative abun- 

 dance of a population of fish over a period of years. This must nec- 

 essarily be so when it is evident that economic conditions, changes 

 in total fishing effort, legislation, or a change in fishing methods 

 might cause fluctuations in the total catch of any species quite apart 

 from any changes that might have occurred in actual abundance. 



