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Figure 11. — Albacore distribution. 



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Figure 12. — Bigeye tuna distribution. 



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Figure 13.— Bluefin tuna distribution. 



in the various oceans. There seems to be 

 a center of abundance off Japan in the 

 Pacific, spreading to the east across the 

 Pacific and reflecting the location of the 

 summer live-bait fishery and the winter 

 longline fishery. Another center occurs 

 along the west coast of North America and 

 reflects the location of live-bait and 

 troll fisheries. A third center represent- 

 ing catches of Japanese longliners spreads 

 across the South Pacific and Indian Ocean, 

 while a fourth area extends across the 

 tropical part of the South Atlantic Ocean. 



Albacore range somewhat further north 

 and south than do either skipjack or yel- 

 lowfin tuna, possibly indicating greater 

 adaptability to cooler water than the latter 

 two species. The tropical catches are 

 longline catches taken at depths where pre- 

 sumably the water is cooler than that at 

 the surface. 



Bigeye Tuna 



Figure 12, showing the catch of big- 

 eye tuna, illustrates a distributional 

 pattern similar to that of the other species 

 discussed, with perhaps the better catches 

 being made in an area of the North Pacific 

 north of Hawaii and another broad band just 

 north of the Equator, representing a zone 

 of enrichment due to the interaction of the 

 equatorial current systems. Here again, 

 information concerning the distribution of 

 bigeye comes primarily from Japanese long- 

 line catches, since the bigeye is not taken 

 except occasionally and in small quantities 

 by surface fishing methods, and where this 

 does occur the species is frequently con- 

 fused with yellowfin tuna. 



Bluefin Tuna 



Bluefin has essentially a different 

 pattern of distribution than the more 

 pelagic tuna species heretofore discussed 

 (fig. 13). This species is harvested by 

 traps in the coastal waters of Japan and 

 the Mediterranean, by purse seines along 

 the west coast of the Americas, and by 

 seines and hook-and-line fishing in other 

 areas > Several species are included under 

 the name "bluefin", with the Australian 

 northern bluefin ( Kishinoella tonggol ) 

 being the most distinct. There is an Aus- 

 tralian southern bluefin, and in the west- 

 ern North Pacific the bluefin is called 

 Thunnus orient alls, or black tuna. The 



