44 U. S. BUREAU OF FISHERIES 
migratory, or ocean-type char the average number of gillrakers was 
18.4 (17 to 21). Some of the other characters which differ in the 
2 types are the coloration, average number of vertebrae, length of 
head, diameter of eye, and depth of caudal peduncle. 
Returns in 1939 from 2 tagging experiments in progress at Karluk 
Lake again pointed to the ‘Jack of homogeneity in the lake’s char 
population. Fish tagged in 1937 were still most commonly found 
in 1939 at the mouths of the same streams at which they had been 
tagged 2 years earlier. Further study will be required to determine 
the | presence or absence of races of chars within the lake itself. 
PINK SALMON 
The study of the causal factors responsible for the fluctuations in 
the abundance and seasonal time of the spawning migration of the 
pink salmon in Alaska was continued during 1939 by “Dr. Davidson 
and §. J. Hutchinson. 
The pink salmon are by far the most abundant species of Pacific 
salmon in Alaska. During the past 10 years an annual average of 
3,150,748 cases of pink salmon have been packed, whereas the red 
salmon, which are second in abundance, have yielded an average of 
only 1,908,072 cases yearly. The pink salmon have a lower market 
value than the red salmon. The 1930-39 annual average catch of 
pink salmon was valued at $13,346.874, while the corresponding aver- 
age value of red salmon was $15,798,340. 
“Because of the complete 2-year life cycle of the pink salmon it 
is possible to build up or break down a population of the species 
within a few years. The record packs of pink salmon from 1934 to 
1938 have been due in part to the successful reproduction of the 
species, and in part to the increase in the intensity of the fishery. 
The size of the spawning populations in 1937 and 1938, in some areas, 
was far from comparable to the total catches of the fishery, and a 
marked reduction in the ensuing populations was predicted. The 
unusually small packs of pink salmon in 1939 in Central Alaska, with 
the exception of the Kodiak and Cook Inlet areas, and in South- 
eastern Alaska, were to be expected. In Southeastern Alaska the 
intensity of the fishery has been mounting in spite of warnings from 
the Bureau of poor escapements and unfavorable spawning con- 
ditions. A number of needed restrictive regulations were recom- 
mended for the pink-salmon fishery in the Central and Southeastern 
sections for 1940. In view of the almost complete lack of escapement 
in some areas in the Southeastern section in 1939, an extensive cur- 
tailment of the fishery will be imperative in 1941 if the populations 
in these areas are to be kept above the critical point of depletion. 
One of the most important factors in the reproduction of the pink 
salmon is the mortality that occurs during their fresh-water existence. 
The stream at Little Port Walter, on Baranof Island in Southeastern 
Alaska, was selected as a site where fluctuations in the fresh-water 
survival of the pink salmon could be determined and the causes there- 
of studied. In March and April, 1939, a combination stop-log dam 
and counting weir was constructed in the stream at Little Port Walter 
which will permit the counting of both the upstream and downstream 
pink salmon migrants. The counts will make possible the determina- 
