10 



10 







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 li. 

 o 



a: 



ID 



15 



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SUBSURFACE - SUMMER a FALL 



m 



1 I I i I I I I I I i M I I I I "^^^ i I I I I I 



n MANNING (CRUISE 26) EAST OF I35'W 

 ■ GILBERT (CRUISE 23) I65°W 



JIL 



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SURFACE- FALL 



TX 



■SURFACE -SUMMER 



SURFACE -SUMMER 



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Or 



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LL 



SURFACE- SPRING 



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^ MITKOF (PSI) EAST OF I55"W 

 n GILBERT (CRUISE 23) EAST OF I55'W 

 ■ GILBERT (CRUISE 23) WEST OF I55°W 

 ^ OVERLAP 



H 



MITKOF (PSI) WEST OF I55"W 



□ MANNING (CRUISE 26) EAST OF I35°W 

 H SMITH (CRUISE 30) WEST OF I55°W 

 ^ OVERLAP 



^m 



H MANNING (CRUISE 25) I65"W 

 □ SMITH (CRUISE 29) I40°W 



50 



I I I 



55 



I M I I I I 

 60 65 



I I I I M I 1 

 70 75 



80 



I I I I '■-"' I I I M I 

 85 105 



FORK LENGTH IN CM. 



Figure 4. --Comparison of size frequencies of albacore taicen in the eastern (open block) eind central 

 (filled block) sectors of the North Pacific, showing the degree of overlap (shaded block). 



coast during 1950. The size range of 9 fish gill 

 netted by the Gilbert (cruise 23) was 51.3 to 

 77.5 cm. fork length, which was similar to that 

 of POFI's troll-caught fish (fig. 4). 



Although only a few albacore were cap- 

 tured on longline gear, their size rainge (fig. 4) 

 is of interest. Those taken on longline by the 

 Manning in the eastern North Pacific were essen- 

 tially the same size as troll-caught fish, while 

 those taken in the central North Pacific were 

 larger. All longline catches made by the Manning 

 were in the sanne area as the troll catches, and 

 3 of the 6 fish caught were alive when landed. 

 Two of these were in such good condition when 

 landed, that they were tagged and released. It 

 would appear that of the albacore taken with 

 longline by the Manning, some were deep- 

 swimming fish and others were captured near 



or at the surface during the retrieving of the 

 gear. A sonnewhat similar situation was noted 

 in longline catches made by the Paolina T . of 

 the California Department of Fish and Game in 

 the nnajor California albacore grounds, 28°N. - 

 33°N. latitude , 1 17°W. - 122°W. longitude, 

 southeast of the Manning's position (California 

 1956). 



Surface and subsurface albacore caught 

 in the central North Pacific vary in size from 

 north to south. In the summer, surface fish 

 captured between latitudes 45 °N. and 48''N. had 

 a size range between 46 cm. and 84 cm. , with 

 the bulk of the fish around 64 cm. in length 

 (fig. 4). To the south (38''N. -41°N., 161°W.- 

 180°), and roughly during the sanne period, 

 August 1955, a Japanese longlining vessel cap- 

 tured 41 large albacore (Nomura 1956). The 



