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I. DESCRIPTION OF THE FISHERY 



The eastern Pacific Ocean yellowfin tuna fishery 1s primarily 

 conducted within an area known as the eastern tropical Pacific (ETP), which 

 is bounded by 40° N latitude, 30° S latitude, 150° W longitude, and the 

 west coasts of North, Central, and South America. For management purposes, 

 the Inter-American Tropical Tuna Commission (lATTC) divides the ETP into 

 two subregions: Dthe Commission Yellowfin Regulatory Area (CYRA), and 2) 

 the remaining area outside the CYRA (Figure 1). Longline and surface gears 

 (baitboats, purse seiners, and bolicheras) are used to catch skipjack, 

 bigeye, bluefin, and albacore tunas in the ETP, as well as yellowfin tuna. 



Jig boats or troll ers also fish in the ETP for tuna but tend to 

 concentrate their fishing effort in the northern fringe of the CYRA. Jig 

 boat catches of yellowfin tuna are usually incidental to those of albacore, 

 the target species, and therefore make only a minor contribution to the ETP 

 yellowfin catch. 



I. A. History of the Fishery 



Catches of yellowfin tuna were reported by U.S. baitboats fishing 

 inshore areas off southern California as early as 1919. Baitboats 

 dominated the fishery until the late 1950's, when major technological 

 advancements in gear precipitated a large scale conversion to purse 

 seining. Between 1958 and 1960 the purse seine component of the eastern 

 Pacific tuna fleet soared from 13% to 54X, and by the end of 1960 the purse 

 seine fleet was operating throughout its present north-south range, from 

 California to Peru. As the fishery extended southward, many Latin American 

 nations, attracted by the performance of the U.S. purse seiners, started 

 developing their own tuna fleets. Since then the fishery has grown fairly 

 steadily, and by 1979 vessels from 18 countries were participating in the 

 fishery. In terms of numbers, the 1979 ETP combined surface fleet 

 consisted of 81X purse seiners, 14% baitboats, 4% bolicheras (small purse 

 seiners of less than 45 mt carrying capacity) and 1% jig boats. The purse 

 seiners accounted for 98% of the ETP carrying capacity, with baitboats, 

 bolicheras, and jig boats contributing the remaining 2%. 



Fishing for yellowfin tuna in the ETP west of the CYRA and east of 

 150° W longitude developed following World War II, when Japanese longliners 

 expanded their range of operations eastward from the western Pacific. 

 Japanese longliners began fisliing in the ETP in the late 1950's, and 

 longliners from Taiwan and South Korea entered the fishery in 1962 and 

 1965, respectively. Until the late 1960's, fishing in the "outside" area 

 was conducted solely by longliners. Large purse seiners began to fish in 

 the outside area in 1968-1969, two years after the yellowfin quota system 

 was established for the CYRA. 



