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Table 1 05. --Fishing conditions by months (35 to 40 



N. , 160° to 170° E.) 



If the foregoing is compared with the eirea from 150 to 160 E. which adjoins it on 

 the west, rather conspicuous differences in the values of the catch rates can be detected, but 

 the trends of increase and decrease are in good agreement for all species. If the area is further 

 compared with the area of 30 to 35 N. , 160 to 170 E. adjacent on the south, it can be seen 

 that the trends of increase and decrease of the catch rates for bigeye tuna and spearfishes are in 

 general agreement, however, there is clearly a lag in the peak of the albacore fishing season, 

 the maximum catch rate at 30 to 35 N. appearing in January with a numerical value of 15.0. 



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If we compare the proportions of striped marlin and broadbill, at 35 to 40 N. , 



150 to 160 E. broadbill are about 60 percent of all the spearfishes. However, in this sea area 



the proportions are reversed and striped marlin are about 55 percent of the spearfish catch. 



As was stated earlier, in the northern areas in general the striped marlin increase markedly 



around September and October, then from Novennber on they decrease rapidly and there is a 



conspicuous increase in broadbill. The data for this sea area are, as shown in table 105, almost 



entirely confined to November and December. Nevertheless, it is worthy of note that broadbill 



are scarce in comparison with striped marlin. It is considered that this sort of phenomenon is 



controlled by the distribution and migrations of the broadbill, and the two sea areas are adjudged 



to differ somewhat in their character as fishing grounds. 



(c) 



170° to 180° E. longitude 



The data for this section are summarized in table 106. 



Table 106. --Fishing conditions at 170° to 180^ E. {35' 

 to 40° N. ) 



The overall catch rate for tunas and spearfishes is slightly less than 9.0, a rather 

 high figure. The most abundant item in the catch is the albacore, which makes up slightly more 

 than 93 percent of the catch excluding miscellaneous fish. It is followed in abundance by the 

 broadbill with slightly more than 5 percent. Spearfishes are scarce making up only slightly more 

 than 1 percent. Black tuna and yellowfin are extrennely scarce, and have almost entirely lost 

 their significance in the catch. 



132 



