26 



FISHERIES OF ALASKA IN 1910. 



RETURN OF MARKED SALMON. 



A number of salmon bearing mutilations of certain fins, apparent 

 brands, or with missing fins, were observed during the summer, as 

 occurs every season. So far as these concern single fins they are 

 not to be referred to any known artificial marks placed upon fish as 

 a means of identification. Twelve of them, however, were red 

 salmon lacking both ventral fins and are identified as returns from 

 a definite marking experiment which has yielded annual results 

 since 1906. This continued return of marked red salmon to south- 

 east Alaska is of particular interest. These fish were marked by 

 Mr. F. M. Chamberlain as fingerlings about three months old, in 

 August, 1903, at Fortmann hatchery, and liberated in Naha Stream 

 above Heckman Lake. The mark consisted of the complete exci- 

 sion of both ventral fins. a The number of marked fish liberated 

 was 1,600. The returns which are considered to have been satisfac- 

 torily identified are shown, by the year and locality, in the following 

 table : 



Marked Salmon Identified Upon Return to Streams, 1906-1910. 



One of the 10 fish credited to Yes Bay in 1910 was caught in the 

 bay by commercial fishermen and preserved by freezing at Ketchikan, 

 where it was examined by the assistant agent on July 23. It was a 

 male 20.5 inches in length and weighed 3f pounds. All the other 

 marked fish assigned to Yes Bay for any year were taken at the 

 Government hatchery at the head of Yes Lake. 



These 40 fish are 2\ per cent of the 1,600 marked. The observed 

 return is certainly somewhat larger and possibly greatly surpasses 

 these figures. An indeterminate number, estimated at between 50 

 and 100, were reported to have been seen at Yes Lake hatchery in 

 1906, but of these no specimens were saved. No account has been 

 taken of these in the above table, since there is no basis for determin- 

 ing how many of the presumed marks were certainly of the same 

 nature as those accepted as representing actual returns. Salmon 

 lacking a single ventral fin are frequently seen in the runs, and some 

 mutilations .of this pair of fins are to be distinguished from the results 

 of artificial marking. While the table shows but one marked fish 



