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I. DESCRIPTION OF THE FISHERY 



I. A. History of the Fishery 



A surface sport fishery for bluefin existed in the California Bight 

 as early as 1898, but commercial fishing did not begin until seines were 

 tried about 1914; the first large catch was reported in 1918. Bluefin have 

 historically been fished opportunistically by the San Pedro purse seine 

 fleet in the California Bight. When larger tuna baitboats converted to 

 seining in the late 50's, the effective fishing range was extended to 

 include the area from Cabo San Lucas to Point Conception, and occasionally 

 as far north as British Columbia. 



In the western Pacific, traps were first used to catch bluefin; 

 purse seining began about 1950, with the first important catches about 

 1958. Trolling gear, baitboats, gill nets, and harpoons are used near 

 Japan. A multispecies longline fishery, with smaller boats (less than 50 

 tons) operating near Japan and larger boats ranging throughout much of the 

 Pacific (Figure 2), also takes bluefin tuna. 



A bluefin fishery in the eastern Pacific consists of the local 

 purse seine fleet out of San Pedro, California, and the "high seas" tuna 

 fleet based in San Diego, California. Since 1975, Mexico has entered the 

 fishery with an expanding purse seine fleet out of Ensenada, Mexico. 



The western and central Pacific fishery is dominated by Japan; 

 however, Taiwan and Korea are also operating longline fisheries in that 

 area. 



I.B. Trends in Catch and Effort 



In recent years, North Pacific bluefin contributed about 1% to the 

 world tuna catch. From 1918 to 1958, the North Pacific bluefin catch 

 averaged 5,066 metric tons (mt) per year (Table 1). After the "high seas" 

 baitboats converted to seining in the late 50's, the fishery expanded to 

 the waters off Baja Califoria, and the average yearly catch in the eastern 

 Pacific climbed to 9,076 mt. A running 10-year average of the bluefin 

 catch in the eastern Pacific reveals an overall decline since 1961, 

 underscored by a projected 1980 catch of 3,000 mt (Figure 1). Further 

 emphasizing a decline in the bluefin catch is the eastern Pacific sport 

 catch, which averaged 7,532 fish per year during 1936 to 1957, but declined 

 to 1,835 fish per year during 1958 to 1979 (Table 1). 



The commercial fishery in the western Pacific (which began about 

 1958) has a mean annual catch for 1964 to 1978 of 14,700 mt, with a range 

 from 4.8 to 30 thousand mt (Table 1). It also shows a significant decline 

 to levels comparable to the eastern Pacific catch. A summary of effort 

 data for the western Pacific is not available at this time. 



