36 
BULLETIN OF THE BUREAU OF FISHERIES 
of 1915 a large number of mature pink salmon returned to the streams in which the 
fry were liberated. A number of ripe eggs were removed from some of the females 
and after fertilizing them they were taken to the hatchery where they later developed 
into normal fry. In the summer and fall of 1917 another large run of pink salmon 
appeared in the streams in which the fry were liberated. Some of these salmon 
were sent to Dr. C. H. Gilbert who, after examining their scales, claimed that they 
had retained their original habit of migrating directly to the sea upon leaving their 
nests in the gravel and returning to the rivers to spawn and die at 2 years of age. 11 
The scales of the pink salmon that have appeared in Snake Creek and in other 
streams in southeastern Alaska on different years have been examined and all show 
bands of growth rings similar to those on the scale in figure 9. The scales of the 
unmarked as well as those of the marked salmon that appeared in the 1931 run in 
the Duckabush River were also similar to the scale shown in figure 10. In fact all 
the evidence thus far collected indicates that the pink salmon mature at 2 years of 
age and until contradictory evidence is found it may be assumed with relative cer- 
tainty that they mature consistently at the close of their second year of life. 
PINK SALMON MARKING EXPERIMENT IN BRITISH! COLUMBIA 
• In the spring of 1931 Dr. A. L. Pritchard, of the Canadian Pacific Biological 
Station, working at McClinton Creek in Massett Inlet, British Columbia, marked 
185,000 pink-salmon fry by the removal of only their adipose fins. The returns 
from this marking experiment are reported in table l. 12 In discussing the significance 
of these returns Pritchard (1932, p. 10) makes the following statements: 
The return of 95 marked fish (52 percent of the recoveries) to McClinton Creek definitely 
establishes that there is a tendency on the part of the pink salmon of this locality to return to its 
native spawning area and that maturity is reached at the end of 2 years. 
It is not unlikely that the 22 fish taken in Massett Inlet and 16 in Naden Harbour and Otard 
Bay would have ultimately appeared in McClinton Creek had they not been caught by the com- 
mercial nets, in which case the return to McClinton Creek would have been 73 percent of the 
recoveries. 
The capture in other localities of 50 fish lacking the adipose fin (27 percent of the recoveries) 
is evidently indicative of a certain degree of wandering. Although not a single fin abnormality 
was discovered among 310,000 pink-salmon fry handled at McClinton Creek and the Tlell River, 
reports from other areas indicate the possibility that such abnormalities may exist to a very small 
extent. It is felt, however, that the indications shown by the large returns from some of the out- 
lying districts should not be considered insignificant. 
According to these statements Pritchard is apparently of the opinion that little 
hazard was involved by the use of only the adipose-fin mark for the future indenti- 
fication of the salmon, and that all of the salmon reported in table 1 were originally 
McClinton Creek fry. 
11 For a detailed discussion of the results from this transplantation of the pink salmon on the Atlantic coast see Reports of the 
Commissioner of Fisheries, 1916 and 1917, pp. 30 and 75, respectively. 
u See A. L. Pritchard (1932) for data on recoveries of the adipose-marked salmon in the various localities as given in this table. 
