-196- 



STATUS REPORT: WESTERN PACIFIC YELLOWFIN TUNA 



by 



Howard 0. Yoshida 



Southwest Fisheries Center 

 Honolulu, Hawaii 



ABSTRACT 



Yellowfin tuna are primarily caught by longline gear in the western 

 Pacific. Although the stock structure of yellowfin tuna is not well known, 

 it has been hypothesized that there are two separate stocks in the Pacific, 

 one in the eastern Pacific and the other in the western Pacific, which are 

 separated by a less clearly defined stock in the central Pacific. A stock 

 production model based on longline catches of yellowfin tuna in the entire 

 Pacific indicated that the stock is capable of sustaining the current level 

 of catches. An important research need for yellowfin tuna in the western 

 Pacific is to determine the relation and the extent of mixing of fish that 

 are available to surface gear and longline gear. 



