ALASKA FISHERY AND FUR-SEAL INDUSTRIES, 1931 41 



NAKNIOK RIVER 



Construction of the 1,200-foot weir in Naknek River was begun on 

 June 1, and on June 17 the river was closed so that no fish could pass. 

 The first sahnou were counted on June 23, and a fair escapement 

 occurred during the next few days. The main run started on July 2 

 and continued heavy tlirough July 18, the record count for any one 

 da}^ being 188,715 on July 6. Counting was continued through 

 August 9, when a total of 1,117,629 red salmon had ascended the river. 

 This is nearly double the number counted in 1929, when this weir was 

 first put in operation, and almost four times as many as were counted 

 in 1930. In addition to the red salmon, 896 kings, 49 pinks, 44 cohos, 

 and 77 chums w^ere tallied at the weir this season. The work was 

 in charge of Adrian Youngsman, under the supervision of Agent 

 Dennis Winn. 



UGASHIK RIVER 



Work of installing the Ugashik weir was started on June 18 and 

 finished on June 24. Counting began on June 29, when four red 

 salmon passed upstream, but it was not until July 8 that the fish 

 appeared in any appreciable numbers. During the next three weeks 

 a very heavy run occurred, reaching its peak on July 20, w^hen 167,275 

 red salmon were tallied. After July 26 there was a rapid decline in 

 the run until August 10, when the work of dismantling the weir was 

 begun. The total count for the season consisted of 1,379,623 red 

 salmon, 12 kings, 7 pinks, 8 cohos, and 145 chums. This escapement 

 was by far the largest that has been recorded since the Ugashik weir 

 was first put in operation in 1926. Henry McFadden, under the 

 supervision of Agent Dennis Winn, was in charge of operations at 

 this weir. 



SALMON LIFE-HISTORY STUDIES 



The study of the life histories of the Alaska salmon was continued 

 during the year. Dr. Willis H. Rich, of Stanford University, has 

 acted in an advisory capacity in planning this work and has taken an 

 active part in certain of the investigations. In Bristol Bay, Thomas 

 Schulte, under the direction of Doctor Rich, collected data bearing 

 on the runs of adult salmon and on the history of the young salmon 

 in the Wood River system. 



The study of the red-salmon runs in the Karluk River was continued 

 by Doctor Rich, assisted by Joseph T. Barnaby. In connection with 

 this study 50,000 young salmon were marked during the course of 

 their seaward migration. The commercial catch was carefully sampled 

 and several hundred adults marked in previous years were recovered. 

 The purpose of these marking experiments is to determine the number 

 of seaward migrants each year as a basis for a more accurate prophecy 

 of later runs. Doctor Rich initiated studies of the life histories and 

 ecology of the red salmon of Afognak Lake and Lake McDonald. 



At Chignik a detailed study of the age groups found in the red- 

 salmon runs was again carried on under the direction of Harlan B. 

 Holmes. The study of the young salmon in Chignik lakes and during 

 their seaward migration was also continued. Seton H. Thompson 

 was engaged in a study of the red-salmon runs of the Copper River 

 and made collections of scales and data from the commercial catch 

 and from salmon taken in some of the more important tributaries. 



