A 



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LIMITS OF AREA OCCUPIED BY MATURING WESTERN ALASKAN SOCKEYE AS DETERMINED BY COASTAL TAG REIURNS AND BY PARASITES 



POSSIBLE EXTENSION OF AREA OCCUPIED BY MATURING WESTERN ALASKAN SOCKEYE AS DETERMINED BY MORPHOLOGICAL AND SCALE STUDIES 



LIMITS OF AREA OCCUPIED BY MATURING KAMCHATKAN SOCKEYE AS DETERMINED BY COASTAL TAG RETURNS AND BY PARASITES 



POSSIBLE EXTENSION OF AREA OCCUPIED DY MATURING KAMCHATKAN SOCKEYE AS DETERMINED DY HIGH SEAS TAG RETURNS AND MORPHOLOGICAL AND SCALE STUD)! 



AREA OF OVERLAP 



V 



LIMITS OF AREA OCCUPIED BY IMMATURE WESTERN ALASKAN SOCKEYE AS DETERMINED BY COASTAL TAG RETURNS AND BY PARASITES 

 LIMITS OF AREA OCCUPIED BY IMMATURE KAMCHATKAN SOCKEYE AS DETERMINED BY COASTAL TAG RETURNS AND BY PARASITES 

 POSSIBLE EXTENSION OF AREA OCCUPIED BY IMMATURE KAMCHATKAN SOCKEYE AS DETERMINED BY OTHER INDIRECT MEANS ISEE TEXT) 

 AREA OF OVERLAP 



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FiGURE 1. — Range and area of overlap for maturing (a) and immature (b) sockeye salmon from Asia and North America 



(Figures 74 and 76 of Margolis et al., 1966). 



REVIEW OF DISTRIBUTION OF 



BRISTOL BAY SOCKEYE SALMON 



AS DETERMINED BY 



COASTAL TAG RETURNS 



Numerous researchers, through tagging experi- 

 ments, morphometric studies, scale studies, and 

 analysis of parasites, have defined certain aspects 

 of the distribution of Bristol Bay sockeye salmon 

 (defined as those sockeye originating in the east- 

 ern Bering Sea from Unimak Island northward 

 to the Kuskokwim River). From a comprehensive 

 review and updating of these studies, Margolis 

 et al. (1966) defined the limits of oceanic dis- 

 tribution of maturing and immature western 

 Alaska sockeye salmon (Figure 1). Examination of 



recent summaries of tag returns^ for 1956-69 

 (Figures 2 and 3) corroborates the general distri- 

 bution pattern of sockeye salmon stocks from 

 western Alaska, from other North American 

 regions, and from Asia as described by Margolis 

 et al. The tag returns show, however, an extension 

 in the range of western Alaska immature sockeye 

 salmon to west of long. 170°E (see Figure 3). 

 Maturing Bristol Bay sockeye salmon, which 

 had been tagged at sea primarily during April, 

 May, and June, are shown to be distributed 



^Aro, K. v., J. Arthur Thomson, and Dorothy P. Giovando. 

 1971. Summaries of salmon tag recoveries in North Pacific 

 coastal and high seas areas from salmon tagging in INPFC 

 statistical Eireas in the North Pacific Ocean by Canada, Japan, 

 and the United States, 1956 to 1969. Fish. Res. Board Can., 

 Manuscr. Rep. 1148, 641 p. (Unpubl.) 



590 



