month shows the possibility of making fairly large catches of this species. Albacore were very 

 scarce in September, but they gradually increased from October on and reached their highest 

 catch rate of 3, 5 in December. The catch rate dropped sharply in January, showing that the 

 fishing season is extremely short. But within the scope of these data the spearfishes mciintained 

 a catch rate above 1. at all times and attained their maximum catch rate in October. 



It is impossible to make a thoroughgoing comparison of these data with those from the 

 area of 30 to 35 N. adjacent on the south because of differences in the seasonal distribution of 

 the data. There appears, however, to be a recognizable tendency for fishing seasons for each 

 species to begin and end about 1 month earlier in this sea ajrea. In addition to this time lag in 

 the fishing seasons, there are considerable differences in the values of the catch rates, but one 

 can recognize many points of agreement in the trends of increase and decline in the catch rates, 

 and it is thought that the populations in the two sea areas have something in common. If this 

 area is further compared with the northern- part of the northeastern sea area, which adjoins it 

 on the west, a good agreement in the trends can be recognized just as in the case of the area of 

 30° to 35° N. , 150° tc 160° E. 



As was stated earlier, the most important element in the catch in this sea area is the 

 spearfishes. Among these the most inaportant are the striped marlin and the broadbill, with 

 which some black marlin are mixed. Table 100 shows the changes from month to month in fish- 

 ing conditions for sharks ajid in the composition of the spearfish catch. 



Table 100. --Monthly changes in shark fishing conditions 

 and the composition of the spearfish catch 

 (35° to 40° N., 150° to 160° E.) 



Data for the sunnmer are completely lacking, so the situation is not well known, but 

 around September striped marlin (including a small number of black 'marlin and sailfish) axe 

 overwhelmingly in the majority , with broadbill appeciring to be less than 10 percent of the total. 

 In October the proportion of broadbill is increased somewhat over September, but striped marlin 

 are still overwhelmingly predominant ajid make up 88. 8 percent of the totcil spearfish catch. In 

 November the proportion of broadbill increases sharply and striped marlin and broadbill appear 

 to be taiken in approximately the same proportions. From December to January the situation is 

 exactly the opposite of that which obtained in Septennber and October, with broadbill swordfish 

 overwhelmingly in the majority. In Jajiuary, particulaurly, the striped marlin catch becomes 

 very small and indeed almost vestigial. We have no data from February on so we do not know 

 what further changes take place. 



The maximunn catch rate for sharks appears in September, after which the catch rate 

 gradually declines until December. They show a slight tendency to increase in January. 



o o 



If this is compared with the area of 30 to 35 N. 



150° to 160° E. 



where the month 



in which the proportions of striped marlin and broadbill in the catch became approximately equal 

 was December, this sea area is about 1 month later. Compared with the northeastern sea area, 

 which is adjacent on the west, and in which the two species attained approximately equal propor- 

 tions around September, there is quite a conspicuous time lag. In the northeastern sea area 



128 



