FISHERIES OF ALASKA IN 1909. 
37 
4.900.000 as against 6,400,000. The 1909 Wood River run was 34 
per cent of the 1908 run; the 1909 Nushagak Bay catch was 76.5 per 
cent of the 1908 catch. 
The relations of the whole redfish runs in Nushagak Bay for the 
two seasons do not appear so definitely, but it is certain that there 
was a great falling off. If the catch and the Wood River run — the 
two accurately known factors — are added together for 1908 and for 
1909, the latter is 64 per cent of the former. These totals give in 
each year the whole run minus the escape up Nushagak, Igushik, and 
Snake rivers, which has never been counted. The conditions which 
reduced the run up Wood River apply more or less exactly to the 
other rivers, and the proportion given may be taken as approxi- 
mating the size relation of the two annual runs. It may be checked 
by another method of estimation. 
A numerical approximation of the whole 1909 run may be obtained 
by the method used for the 1908 run and detailed in the 1908 report. 
Reducing the 1908 maximum and minimum estimates for Nushagak, 
Igushik, and Snake rivers in the same proportion that the Wood 
River run has been reduced, adding in each case the Wood River run 
and the catch on the bay and averaging the two totals, nearly 6,800,000 
is obtained as an estimate of the total run of red salmon into Nusha- 
gak Bay in 1909. This is 57 per cent of the corresponding 1908 
estimate, and thus it is safe to say that the current run was between 
57 per cent and 64 per cent of the 1908 run. Of this total of nearly 
6.800.000 fish, 85 per cent have been actually counted (Wood River 
run and the catch), and it is plain that the estimate is not a guess. 
The 1909 run was not fewer than 6,200,000 and not more than 
7,400,000. The escape to the spawning grounds was between 20.5 
per cent and 34.3 per cent of the whole run. 
If the number escaping to the spawning grounds in 1909 is just 
sufficient to maintain the run which entered the bay, the rate of 
increase is between 200 per cent and 400 per cent, depending on which 
of the extreme estimates, maximum or minimum, is taken as a basis. 
Considering the relation of take to escape in the past two seasons and 
the strong presumption of a slowly declining fishery, this 1909 escape 
is probably insufficient, and 400 per cent is a safe extreme as a pos- 
sible rate of increase. From the results of the 1908 investigations 100 
per cent seems a certain minimum. We may therefore conclude that 
the Nushagak region during recent years is reproducing red salmon 
by natural propagation at a rate of increment not lower than 100 per 
cent nor greater than 400 per cent. In other words, for every salmon 
reaching the spawning grounds, from two to five return several years 
later, and of these returning salmon from one to four (the increment) 
