Table 4. --Number of tags released and number recovered 1n tagging experiments in southeastern 



Alaska, 1938-42 and 1945. 



i/l 



Not included in number recovered. 



statistic for recoveries in traps and seines and the 

 mean and variance of the number of miles traveled for 

 recoveries in traps. 



MIGRATION ROUTES AS 



DETERMINED FROM TAG 



RECOVERIES 



The capture-recapture method of studying animal 

 migration has the inherent limitation that no infor- 

 mation is provided on the actual path followed from 

 the point of original capture to the point of recapture 

 unless multiple recaptures are made. Precise charting 

 of migratory routes requires frequent position deter- 

 mination without disturbing the normal migratory 

 behavior of the animal. Multiple recaptures of the 

 same tag, if any, were not reported for the 1938-42 and 

 1945 experiments. Determination of migratory 

 pathways was further restricted by locations of release 

 sites and the operation of the commercial fishery that 

 provided the primary recovery effort. Because of these 

 limitations, the analysis presented here is concerned 

 only with broad aspects of the migration patterns. 



Migration Between Northern and 

 Southern Southeastern Alaska 



The separation of stocks of southeastern Alaska 

 pink salmon into virtually independent northern and 

 southern runs, as mentioned in the historical review 

 above, has been valuable to fishery management 

 because it permits regulation of the pink salmon 

 fishery as two units. Since all experiments covered in 

 this report were conducted in the northern part of 

 southeastern Alaska, evidence of separation consists 

 only of the lack of recoveries in the commercial fishery 

 operating in the southern part. Of 6,435 recoveries in 

 known gear, only 102 (1.6%) were recovered in 



Sumner Strait, which forms the northern boundary of 

 the southern part of southeastern Alaska. Only one 

 tagged fish was recovered as far south as Clarence 

 Strait (Fig. 1). 



The recoveries in Sumner Strait are compared with 

 total recoveries by known gear from all releases in Icy 

 Strait and Chatham Strait in Table 6. The percentage 

 of tagged fish recovered in Sumner Strait increased 

 from Icy Strait southward and was highest for lower 

 Chatham Strait. Only one fish from the releases in 

 Salisbury Sound (Table 3) was recovered in Sumner 

 Strait. These results indicate little transfer of fish 

 from the northern part to the southern part of 

 southeastern Alaska and thus agree with the con- 

 clusions of other investigators. 



Migration Through Peril Strait 



There are three possible channels through which 

 pink salmon can enter the inner waters of northern 

 southeastern Alaska from the ocean: Icy Strait, lower 

 Chatham Strait, and Peril Strait (Fig. 2). Because 

 Peril Strait was closed to fishing during the period of 

 these experiments, no tag recoveries could be ex- 

 pected from that area. The yearly occurrence of major 

 runs in Icy Strait and lower Chatham Strait is well 

 known, but there is little information available con- 

 cerning migration of pink salmon through Peril Strait. 



In 1945, tagging experiments were conducted at the 

 western entrance of Peril Strait in Salisbury Sound 

 (Tables 3 to 5). In the first experiment (5 August), 635 

 pink salmon were tagged; in the second and third ex- 

 periments (12 August), 722 were tagged. The 12 

 August experiments were combined because the 

 release traps were only a few miles apart. Two types of 

 tags, one bearing the single number 11 and the other 

 the number 12, were used to identify fish released on 5 

 August. On 12 August, tags bearing the number 12 



