escapement of 220,675 red salmon was well distributed over the season as a result of the 

 policy designed recently to bolster the weak mid-portion of the run. The research program 

 at Karluk Lake is a long-term investigation of the causes of changes in survival rates of 

 young red salmon during the freshwater stages. In past years the work at Karluk Lake has 

 been principally concerned with gathering basic data on numbers of adults entering the 

 lake, their age, length, and fecundity, as well as on sampling of the lake residents. 



In 1957 the research was expanded to include studies on survival, or mortality in 

 the spawning st^reams. Groups of adult salmon entering streams were counted, tagged, and 

 followed through their life spans in the streams. 



Tl'ie gravel of the spawning beds was sampled to determine eggs deposited per unit 

 area in the streams under study. It is planned to enumerate the fry emerging from these 

 streams in the spring. 



At Bare Lake a detailed investigation of tlie effect of the addition of commercial 

 fertilizer on survival of red salmon has been under way since 1950. Nitrate and phosphate 

 fertilizer was added annually fi'om I950 tlirougli 1956. An increase in the growth rate of 

 young lake resident red salmon has been obsex-ved, but the general results have been incon- 

 clusive. Because it is small and shallow, Bare Lake is not typical of important red 

 salmon producing lakes. Other factors besides food production for the lake residents may 

 be instrumental in the freshwater survival of red salmon. 



Bare Lake was not fertilized in 1957> but reseai'ch was continued on conditions in 

 the lake and on the biology of the young salmon. Observations on Bare Lake will be con- 

 tinued for as long as is necessary to serve as a check and to substantiate results already 

 obtained under fertilized conditions. 



CHIGNIK 



The 1957 red salmon run, thougli not as good as I956, does not compare unfavorably 

 with the preceding nine-year average (fig. 2^4). 



Fishery management relied successfully on an extended closed area at the mouth of 

 the Cliignik River and a relatively fixed weekly schedule of 12-hour fishing periods to 

 achieve its objective of obtaining a more uniform escapement of spawning stock throughout 

 the entire run. Bie escapement percentage of the total run, especially during the heavy 

 fishing period from mid-June to mid- July was satisfactory (fig. 25). Substantial escape- 

 ments from each segnent of the run should contribute materially to increased and steadier 

 futiu-e production. 





1 l^ESCAPEMENT 



1925 '30 '35 '40 '45 '50 '55 



Figure 24.--Chignik red salmon 



catch and escapement 



UNE 30 JULY 10 20 30 AUGUST 10 



Figure 25 . - -Relation of Chignik red salmon 

 escapenrient to total run, 1957 



13 



