■183- 



I. DESCRIPTION OF THE FISHERY 



I. A. History of the Fishery 



Skipjack tuna ( Katsuwonus peTamis) are widely distributed in the 

 Pacific Ocean (Figure IT. The major fisheries are located adjacent to 

 continents and islands where oceanographic features such as upwelling 

 concentrate large numbers of fish near the surface. Of the major Pacific 

 fisheries, the Japanese pole-and-1 ine, live-bait fishery in the western 

 Pacific is by far of greatest antiquity. The origin of the Japanese 

 fishery is obscure; however, skipjack tuna fishing is mentioned in the 

 oldest (semi legendary) account of Japanese history. Keen (1965) stated 

 that the Japanese pole-and-1 ine fishery for skipjack tuna dates from at 

 least the early part of the Tokugawa Period (1603-1868). 



The Japanese skipjack tuna fishery, which was earlier limited to 



coastal waters of Japan, has expanded eastward and southward into 



subtropical and tropical waters. The expansion of the fishery into these 



waters involved not only pole-and-1 ine vessels but purse seiners as well. 



Skipjack tuna fisheries are also well developed or developing in 

 Hawaii and many island areas in the western Pacific. Uchida (1975) 

 reviewed the recent development of skipjack tuna fisheries in the central 

 and western Pacific, including those of French Polynesia, Hawaii, Samoa, 

 Tonga, Australia, Fiji, Tuvalu (El lice Islands), Indonesia, Korea, New 

 Hebrides, New Caledonia, New Zealand, Papua New Guinea, Philippines, 

 Solomon Islands, and the Trust Territory of the Pacific Islands. Kiribati 

 and Singapore also show landings of skipjack tuna (Food and Agricultural 

 Organization of the United Nations 1979). Japan is the major producer of 

 skipjack in the western Pacific, and also is involved in the fisheries of 

 some of these countries or political entities through joint venture 

 arrangements. Although the FAO yearbooks of fishery statistics show no 

 landings of skipjack tuna in Taiwan, there apparently is a troll fishery of 

 unknown magnitude there. 



The U.S. (Hawaii) has a small surface fishery in the western 

 Pacific and American tuna seiners have been making western Pacific 

 exploratory fishing cruises. 



I.B. Trends in Catch and Effort 



The catch of skipjack tuna in the western Pacific increased from 

 224,400 to 532,296 metric tons (mt) during 1970-1978 (Figure 2). The catch 

 in the Japanese pole-and-1 ine fishery between 50°N and 30°S latitude and 

 110°E and 150°W longitude ranged from 119,643 to 245,611 mt, and showed an 

 increasing trend between 1970 and 1977 (Figure 3). 



