FISHERY BULLETIN: VOL. 73, NO. 4 



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ESTIMATED TOTAL ANNUAL FISHING EFFORT ( MILLIONS OF HOOKS ) 



Figure 7.-Relation between CPUE of albacore in weight and 

 numbers and total effort, 1963-71. 



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EFFORT (MILLIONS OF HOOKS) 



Figure 8.-Relation between CPUE of albacore and effort in 

 areas south (A) of lat. 20°S and north (B) of lat. 20°S. 



should be repeated here, however, that despite the 

 expansion into new fishing grounds the overall 

 trend for the fishery has been a decline in CPUE 

 (Figure 5). Furthermore, in the southern grounds 

 to which the fishery has expanded, the albacore 

 catches, as will be shown in a later section, are 

 composed of a large proportion of smaller fish. 

 These smaller albacore may not be the optimum 

 size at which to harvest the stock. 



from 1963 to 1971 in the old grounds were all less 

 than five albacore per 100 hooks, whereas in the 

 new grounds they were all greater than five per 

 100 hooks during the same period. Another 

 difference is that in the old grounds the mean 

 CPUE has been declining with increasing effort. 

 In the new grounds the CPUE increased 

 with increasing effort from 1963 to 1966. In 1967, 

 the CPUE declined slightly and from that year to 

 1971 the CPUE appears to have stabilized around 

 six albacore per 100 hooks. These facts suggest 

 that the albacore fishery has been able to maintain 

 itself by continuously expanding geographically to 

 take advantage of better CPUE in newer areas. It 



Apparent Abundance of Yellowfin Tuna 



The discussion of the apparent abundance of 

 yellowfin tuna will be primarily in terms of how it 

 relates to the apparent abundance of albacore in 

 the Samoan longline fishery. For one thing, 

 although albacore are selectively fished for by the 

 fleet, yellowfin tuna (and small numbers of other 

 species) are also caught by the longlines, and the 

 CPUE for one species may affect the CPUE of 

 another (Rothschild 1967). The CPUE for one 

 species may affect that for another species 

 because, in computing the CPUE, the total effort 

 expended was applied to the catch of each species 

 without regard to the competition of the species 



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