THE MIGRATION OF PACIFIC SALMON IN 

 BRITISH COLUMBIA WATERS 



By W. A. CLEMENS, R. E. FOERSTER and A. L. PRITCHARD 



PACIFIC BIOLOGICAL STATION, FISHERIES RESEARCH BOARD OF CANADA, 

 NANAIMO, B. C, CANADA 



Migrations of salmon have been investi- 

 gated extensively in British Columbia over 

 a period of 12 years by the Fisheries Re- 

 search Board of Canada. Two procedures 

 have been followed, namely, tagging of 

 adults for the purpose of determining the 

 movements of the fish in the sea, and mark- 

 ing of young to indicate the extent of return 

 to the natal stream. With the exception of 

 one preliminary experiment pertaining to 

 the function of the olfactory nerves, no at- 

 tempt was made to determine the causatiye 

 factors involved in the movement of the fish. 



Methods 



In the tagging programs, the majority of 

 the fish were obtained from the commercial 

 fishermen operating the usual types of gear 

 (troll, purse seine and trap) in the various 

 fishing areas along the coast. In a few in- 

 stances expert troll fishermen were employed 

 to catch spring and coho salmon solely for 

 tagging purposes. A serially numbered 

 aluminum strap tag was affixed to the dorsal 

 portion of the caudal peduncle with a special 

 pair of pliers. A reward of 50 cents was 

 offered for the return of a tag together with 

 information concerning date and place of 

 recapture. Thus the histories of individual 

 fish could be determined. 



In the marking programs, fry, fingerlings 

 and yearling fish were captured at the time 

 of their seaward migration and marked by 

 the removal of two or more fins. Rewards 

 were offered for adult fish bearing such 

 scars. Recoveries were made by fishermen, 

 observers in canneries and employees at 

 weirs on the streams. Because of the dis- 

 tinctive marks, these fish could be identified 

 as belonging to the various experimental 

 groups. 



Discussion will be limited to the results 



of the tagging of spring and sockeye and to 

 the marking of sockeye and pink salmon. 



The Migration of Spring Salmon 



During the years 1925 to 1930 inclusive, 

 tagging programs were prosecuted at vari- 

 ous places on the west coast of Vancouver 

 Island, on the west and north coasts of the 

 Queen Charlotte Islands, in the vicinity of 

 the islands near the mainland shore in 

 northern British Columbia, off the north- 

 eastern coast of Vancouver Island and in 

 the Gulf of Georgia. Consideration of the 

 detail of each isolated experiment would 

 only serve to confuse the broader general 

 issues. For that reason one typical experi- 

 ment is selected as an illustration in this 

 presentation and the rest of the data are 

 briefly summarized. 



In May and June, 1925, 1,125 spring sal- 

 mon captured in the commercial troll fishery 

 off Barkley Sound on the west coast of Van- 

 couver Island were tagged in the manner 

 described. In subsequent years 123, or 11 

 per cent, were recovered. The distribution 

 of these recoveries was as follows : Barkley 

 Sound, 8 ; Cape Flattery, 3 ; Strait of Juan 

 de Fuca (British Columbia waters), 7; 

 Strait of Juan de Fuca (United States 

 waters), 7; Puget and Washington Sounds, 

 11 ; Fraser River, 6 ; Pacific coast of Wash- 

 ington, 2 ; Columbia River, 74 ; Pacific coast 

 of Oregon, 2 ; Sacramento River, 2, and un- 

 known locality, 1. 



In spite of the factors which might affect 

 the collection of returns in such an experi- 

 ment, e.g., the loss of tags, the natural mor- 

 tality of the fish, the failure to return the 

 tags, the effect of fishing intensity on the 

 collection, etc., three general conclusions are 

 justified. 



1. Spring salmon make long and compli- 



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