100° W. 



60 W 



30° W. 



50° N 



30° K 



30° S 



50° S. 



50° S. 



100° W 



60° W 30° W. - 0° 



Figure 1. — Areas used In this study. 



30° E. 



percent over the optimum, caught by about 42 

 million hooks, almost 1,300 percent above the 

 equilibrium level. A large part of the effort in 

 the Bahia, Rio de Janeiro, Florida, and 

 Benguela areas nnust have been directed at 

 albacore, since these are the best albacore 

 fishing areas (table 4). 



The widespread declines in catch rates and 

 the apparent acceleration of decline rates for 

 some species are consistent with constantly- 

 increasing fishing pressure. From a very 

 modest beginning in 1956, the number of hooks 

 fished in the Atlantic by the Japanese long- 

 liners rose to nearly 3 1/2 million in 1957. 

 By 1962 this nunnber had increased l6-fold, 

 and in 1965 it was nearly 100 million hooks or 

 more than 25 times the 1957 effort (table 1). 

 These 100 million hooks were fished by ap- 

 proxinnately 150 Japanese longliners. Since 

 then the number of Japanese longliners fish- 

 ing in the Atlantic has decreased--in the first 

 3 months of 1968 about 75 Japanese longliners 

 were fishing at any given time in the Atlantic. 



In recent years, however, substantial num- 

 bers of longliners from other countries have 

 entered the Atlantic tuna fisheries. The de- 

 crease in numbers of Japanese longliners has 

 been made up by about 50 South Korean long- 

 liners, plus perhaps 20 or 30 longliners fronn 

 other countries, including Cuba, Venezuela, 

 and China (Taiwan). Reports are persistent 

 that new vessels in addition to the longliners 

 now fishing are being built or planned for 

 Atlantic operations. Thus it seems likely that 

 in 1968 the total level of fishing effort in the 

 Atlantic by longline is comparable to the ap- 

 proximately 100 million hooks fished by the 

 Japanese in 1965. 



If decline rates for yellowfin tuna continue 

 at the 1965 level (or accelerate), by mid-1970 

 the catch of yellowfin tuna per 100 hooks will 

 be 0.5 fish or less in all areas, reducing what 

 was a species of major importance to little 

 more than an incidental catch. The result will 

 be to focus nearly all of the fishing effort on 

 albacore, the only other species sufficiently 



