PROGRESS IN BIOLOGICAL INQUIRIES, 1939 45 
tion of the number of fry resulting from the spawning of a known 
number of eggs each season. ‘The ‘adults returning from the libera- 
tion of a known number of fry each season will be determined from 
the subsequent spawning populations, and in this way the percen- 
tage of mortality during both the fresh-water and salt-water existence 
may be calculated. 
In order to carry on the necessary weekly observations of the influ- 
ence of environmental conditions on the brood in the stream, and 
conduct laboratory experiments on the salmon leading to a_ better 
understanding of their reactions to certain environmental factors, 
a laboratory-residence building was constructed at Little Port Walter 
during the past summer. Ne permanent biological station foreman 
will be appointed for the purpose of maintaining the equipment at 
the station and making the necessary biological observations regard- 
ing the survival of the salmon in the stream. It is expected that the 
results from the continuous operation of this field station will give 
insight into the survival of the pink-salmon brood in this region 
of Alaska each year, and permit more accurate predictions as to the 
size of the annual runs of pik salmon. 
Spawning escapement.—The first count of adult salmon through 
the weir at Little Port Walter in 1939 was made on August 17, and 
by August 22 the run was well under way. A total of 16,830 pink, 
122 coho, 117 chum, and 7 red salmon was counted through the 
weir. Of the 16,830 pink cies 51.56 percent were males, and 48.44 
percent were females. The pink-salmon escapements through the 
weir at Little Port Walter prior to 1939 were: 1934, 6,952; 1935, 
6,073; 1936, 5,164; 1937, 7,085; and 1938, 6.467. The adults in 1939 
came from the spawning population of 1937, and, since the commer- 
cial fishery at Little Port Walter has been neghgible, this is the first 
year when the returns were greater than 114 to 1. Unfortunately, 
it cannot be determined whether this sur mal occurred in the salt- 
water or fresh-water period, but such fluctuations in the future, it is 
hoped, may be traced to the influence of certain environmental 
factors. 
Tagging program.—With the opening of the commercial fishing 
season in Eastern District on July 5,.a pink-salmon tagging program 
was instigated. Pink salmon were tagged and released each week 
end throughout the fishing season. All the tagging was conducted 
from the 2 traps in Tebenkof Bay, which are the first traps encoun- 
tered by the migrating salmon as they enter Chatham Straits from 
the south and travel the inside waters to their spawning grounds in 
Frederick Sound and contiguous waters. <A_ total of 2,100 pink 
salmon were tagged during the season. The general trend of the 
migration, as indicated by tag recoveries, 1s northeast into the inside 
waters of Frederick Sound, Stephens Passage, and the Stikine River 
region. There were 684 tags recovered, yielding a 32.57 percent re- 
turn from the experiment. Of this number of recaptures, the ma- 
jority traveled a distance of 40 miles or more and were taken within 
5 days after the tagging date. The greatest distance that a tagged 
salmon traveled before being rect iptured was 162 miles. One speci- 
men, taken the day after tagging, had traveled over 100 miles. Thus 
it becomes evident that the pink salmon entering Lower Chatham 
241635—40——4 
