The Japanese Atlantic Longline Fishery, 1965, 



and the Status of the Yellowfin 



Tuna and Albacore Stocks 



By 



JOHN P. WISE and WILLIAM W. FOX, JR., Fishery Biologists 



Bureau of Commercial Fisheries 

 Tropical Atlantic Biological Laboratory, Miami, Florida 33149 



ABSTRACT 



Fishing effort reached nearly 100 million hooks in 1965, a level which is more 

 than the yellowfin tuna stocks can support and remain commercially productive. As 

 catch rates for yellowfin tuna decrease, more and more fishing will be directed 

 toward albacore. 



Data on catches and fishing effort by the 

 Japanese Atlantic longline fleet have been 

 published by Shiohama, Myojin, and Sakamoto 

 (1965), and by the Fisheries Agency of Japan 

 (1966, 1967a, 1967b). Analyses of part or all 

 of the data have been carried out by Paiva 

 (196ia, 1961b, 1962), Moraes (1962), Nakagome 

 and Suzuki (1963), Lima and Wise (1963), 

 Griffiths and Nemoto (1967), Le GuenandWise 

 (1967), Sakamoto (1967), Wise ( 1968), and Wise 

 and Le Guen (in press). 



The principal species (in numbers) in the 

 fishery for the 10 years 1956-65 have been 

 yellowfin tuna""" (41 percent), albacore (39 

 percent), bigeye tuna (11 percent), and blue 

 marlin (2 percent) --all other species make up 

 only about 7 percent of the catch (table 1). 

 These proportions have not been constant --the 

 catch figures for the first 3 years of fishing 

 on a commercial scale (1957-59) were: yellow- 

 fin tuna 77 percent, albacore 18 percent, big- 

 eye tuna and blue marlin 2 percent each, all 

 other species only 1 percent. The major reason 

 for the change in species composition has been 

 the decrease in catch rate of yellowfin tuna 

 from nearly eight fish per 100 hooks in the 



Note. — Estimates of catch, effort, and catch per unit 

 effort in this paper are the best currently available. They 

 supersede estimates in Le Guen and Wise (1967), Wise 

 and Le Guen (in press), and Wise (1968). Corrections are 

 minor, except for new estimates for 1961 and 1962 based 

 on information received from A. Suda of the Far Seas 

 Fisheries Research Laboratory of the Fisheries Agency 

 of Japan (personal communication). Suda pointed out cer- 

 tain necessary corrections in the data for 1961 and 1962 

 as published by Shiohama, Myojin, and Sakamoto (1965). 



■"^ Common names only are given in the orlginalJapanese 

 reports. 



whole Atlantic in 1957-59 to just under one 

 fish per 100 hooks in 1965. (We have assumed 

 throughout this study that the part of the fleet 

 included in the logs available for tabulation 

 is representative of the effort, catch, and 

 geographical distribution of the whole 

 fleet.) 



Wise (1968) reviewed the development of 

 the fishery from its beginning in 1956 through 

 1964, in the areas shown in figure l.He pointed 

 out that major changes took place in the fishery 

 in 1964, and showed these changes as com- 

 parisons of percentages from 1963 to 1964. 

 The same tendencies are apparent in the 1965 

 data compared with the 1963 data: 



The greatest percentage increases in fishing 

 effort from 1963 to 1964 were in the Guianas, 

 North Oceanic (West), Bahia, and Rio de 

 Janeiro areas --all are western Atlantic areas 

 and three of them are among the best regions 

 for albacore. From 1963 to 1965 the largest 

 percentage increases were in the areas of 

 Benguela, North Oceanic (East), Gulf of Guinea, 

 Guianas, and North Oceanic (West) (table 2). 

 Fishing effort shifted from 1963 to 1964 to 

 the western Atlantic and to good albacore 

 areas, but the change from 1963 to 1965 was 

 in the opposite direction, to the eastern Atlan- 

 tic, slightly favoring better yellowfin tuna 

 areas. 



