PROGRESS IN BIOLOGICAL INQUIRJES, 1924 27 



of the tagging operations. A report giving a detailed analysis of 

 the data is in an advanced stage of preparation. '^ . 



A number of the important spawning streams in Bristol Bay, 

 along the Alaska Peninsula, and in southeastern Alaska were visited 

 and observations of value recorded bearing; on the life history of the 

 salmon and on the number of spawning adults found in the various 

 streams. In certain cases it was found that the streams were not 

 as heavily populated as in other years. A more accurate census of 

 the spawning population than can be obtained through such obser- 

 vations has been made on several streams. Weirs are erected for 

 this purpose and the number of salmon passing through is accu- 

 rately recorded by observers stationed at the weirs. Such censuses 

 were conducted in the Karluk and Chignik Rivers and in Letnik 

 Creek (Afognak Island). 



SALMON OF THE PACIFIC COAST STATES '. 



These investigations have been continued. Tlie study of the 

 chinook salmon taken by troll and purse seines off the mouth of the 

 Columbia Eiver, in Monterey Bay, and at points along the northern 

 coast of California, which has been carried on for a number of years 

 by Willis H. Rich, has been completed and a report submitted for 

 publication. The results show that a high percentage of the fish 

 taken in the ocean are small and immature and would not have 

 entered the streams for the purpose of spawning for at least one 

 more year. These small fish are known to be of poor quality, and 

 the taking of them results in a serious economic loss. The ])ercent- 

 ages of mature and immature fish so taken have been worked out 

 for the entire season, and it is shown that there are relatively many 

 more immature fisli taken during the early part of the fishing 

 season than later. The relative maturity of the fish was determined 

 by careful measurements of the eggs, and it was found that a differ- 

 ential growth occurs during the spring and summer just preceding 

 the fall in which the fish spawn. This differential growth results 

 in a great increase in the relative size of tlie eggs, so that quite early 

 in the season females that are due to spawn in the fall may be dis- 

 tinguished from those of the same age and size, but which will not 

 spawn for at least one more year. Recommendations are made for 

 the control of the fishery. This paper also deals with the rate of 

 growth of chinook salmon in the ocean. The capture of fish during 

 their life in the ocean has provided ah unusual opportunity for 

 such a study. 



The extensive experiments in marking young salmon on their 

 liberation from the various hatcheries on the Columbia River have 

 been continued with gratifying results. This work is being con- 

 ducted by Harlan B. Holmes, scientific assistant, who has been ma- 

 terially assisted by the fine cooperation afforded by the Oregon Fish 

 Commission. During the commercial fishing season of 1923 and 

 1924, and the spawning season of 1923, a constant search was made 

 for returning marked fish. As a result of these efforts, records of 

 approximately 500 marked salmon were reported. 



Returns from a marking of 65,000 chinook salmon from eggs 

 taken on the Willamette River in 1919 and liberated at Bonneville 

 18838—25 3 



