The Salmon An 
migration. [ think it would be absurd to call the fish belated orilse 
we caught on oth August (Fig. 28), weighing 27 lbs., on its first 
return from the sea, or a 60-lb. fish arriving from the sea for the first 
time at the ripe age of seven years. 
The marking of the smolts and their recapture afterwards has 
enabled us to know for certain whether the small spring fish will be 
plentiful or scarce, and what the other runs that follow will be, long 
Ds 

; é ‘¢ Ps t. 4 
COUR ASCE DEN 
Fic. 37.—Showing mark of first small Spring fish, 94 lbs., caught 18th February 1907. 
Marked as Smolt May 1905. 
) 
before the fish enter the river, and it also enables us to tell whether 
the fish will be large or small. 
I will now return to the grilse from 4 to 13 lbs. that run from the 
middle of May to the middle or end of December. These spawn the 
same season as they come up and become kelts (Fig. 38). Many ot 
them, both male and female, die after spawning, the mortality amongst 
males predominating. A few of those that return to the sea re-enter 
the rivers as clean fish, after being three or four months in the sea. 
On their return about June they are double the weight they were 
when they went down, and as the season advances the number and 
weight increase. We know this from marking the kelt grilse. 
Until a year ago we called all these fish that returned bull-trout, for 
G 
