142 
BULLETIN of the bureau of fisheries. 
CAREERS OF INDIVIDUAL SALMON RETAKEN. 
CHINOOK SALMON. 
Of the ehinook salmon, three, numbers 109, no, and 115, were retaken in traps in 
the immediate vicinity of the point where they were liberated. They were taken at the 
next lift of those traps on August 15 and may have entered the traps at any time during 
the interval of a little less than 24 hours following their liberation. These three salmon 
are the only fish of the marked series reported retaken by the traps of the vicinity. 
They are of interest chiefly as showing that the great majority of the fish took to the 
main channel in the direction in which they were liberated. The currents at the time 
of liberation were toward the trap field. On the theory that salmon stem the currents in 
the tide waters as well as in fresh water, it is obvious that the liberated fish would be 
directed away from the trap field. These observations are in the main in harmony with 
this theory. 
Chinook number 1 13 was caught 6 days after liberation and by a purse seine operating 
near Republic spit. Republic spit is a point marked by the wreckage of a vessel which 
obstructs the channel off the south shore of Sand Island. It is located about 4 miles 
down the river from the state trap. The aluminum marking button of this salmon is 
quite smooth. Had the fish gone out into the pure sea water it might have shown some 
slight signs of corrosion. Six days in brackish water would scarcely lead to corrosion 
of the aluminum. It is probable, therefore, that this salmon had spent the time swim- 
ming back and forth in the tide water of the vicinity in the process of acclimatization. 
Whether or not it swam long distances, either upriver or out to sea, does not appear, but 
judging by the results of the comparison with specimen number 80 it is probable that 
the time of number 113 was spent in the relatively fresh water in the neighborhood of 
Sand Island. 
Number 80 was taken 15 miles up the river from the state trap and on the eleventh 
day after liberation. The time required by a straightaway swim for the salmon to 
travel 15 miles could not be over one or two days (three of the silvers averaged over 7 
miles a day, see numbers 75, 76, and 89) ; hence this fish had about 9 days in which its 
movements are not accounted for. The corrosion of its tag is slight on one side but 
quite extensive on the other. So much corrosion in the short time of 1 1 days can onty 
be accounted for on the theory that the fish was in relatively salt water. My guess would 
be that this fish went well out toward the jetty or even beyond during its 11 days’ stay, 
and that the average of its time was spent in water as salt as in the vicinity of lower 
Sand Island or of Canby light. 
Chinook number 1 23 was out 3 1 days, yet this salmon had traveled upriver only 1 5 miles 
when taken near Brookfield. Its button was the second deepest etched of the series 
recaptured. The corrosion indicates a sojourn in salt water or in relatively concentrated 
brackish water. The evidence given by the corrosion of this button is to my mind 
conclusive evidence that its bearer had spent considerable time well below the point 
where it was liberated, probably at or beyond the lower end of Sand Island. I would 
