32 
BULLETIN OE THE BUREAU OF FISHERIES 
only individuals that can be considered as returns, it is interesting to note that the 
dorsal scars on the 5 salmon having only these scars were identical to the dorsal 
scars on the 23 marked salmon. It is not at all unlikely that these 5 individuals 
resulted from the fry whose adipose fins were missed when they were marked. 
Regardless of this close resemblance, these 5 individuals cannot be considered as 
returns, for by so doing, the 10 salmon with only adipose scars would likewise have 
to be considered as returns. This as previously pointed out 8 would be a hazardous 
thing to do. 
Figure 8. — Snake Creek at Olive Cove, Alaska, and vicinity. All of the streams shown on the map support a large population 
of pink salmon each season. 
The method used in calculating the number of marked salmon in the entire 
run of pink salmon in Snake Creek in the summer of 1932 is given in the following 
equation: 9 
23 + (l0,640X 7 -|U)_5 4 
where 23 equals the number of marked salmon found in the trap, 10,640 equals the 
total number of salmon counted through the gates in the weir, 7,944 equals the 
8 See discussion on page 29. 
> This equation is based upon the assumption that there was the same proportion of marked salmon in the numbers counted 
through the weir as in the numbers lifted out of the trap. There is no reason to believe that the trap was selective in regard to 
the marked salmon; i. e., that more of the marked salmon in the run passed through the trap than through the gates in the weir. 
On days when the water in the creek was low and the visibility good, marked salmon were observed passing through the gates 
in the weir. During these times a total of 9 marked salmon were seen passing through the gates. 
