December. Bigeye tuna are abundant frona Jeinuary to April, with peaks in their catch rate in 

 Januciry and April and the mjiximum catch rate for the year in the latter month. The albacore 

 catch rate improves suddenly after November and attains its high of the year, slightly over 9. 5, 

 in December. Thereafter it decreases gradually until March, and then the catch rate again 

 improves in April to slightly less than 6, 9. These fish are generally scarce in the summertime, 

 but a catch rate of slightly more thcin 2. in June indicates a possibility that there may be good 

 albacore fishing at times. Spearfishes are generally scarce, but they appear to become some- 

 what more abundant in the sunnmer. 



, o o 



If the foregoing is compared with the area of 160 to 170 E. adjacent on the west, 



(1) Black tuna begin to be taken 1 month earlier in this sea area and the season 

 appears to end 1 month earlier. 



o o 



Table 96. --Fishing condition by months (0 to 30 N. , 



170° to 180° E.) 



(2) It is difficult to detect any differences in yellowfin fishing conditions between the 

 two areas, but the catch rates have snnaller values in this sea area. 



(3) Bigeye tuna are generjilly less abundant in this area, but the seasonal rise cind 

 fall in the catch rate is approximately similar. 



(4) The albacore catch rates are also generally lower in this sea area, but the 

 seasoned variations in fishing are generally similar. It appears that these changes tend to take 

 place somewhat earlier in this sea area. 



(5) It appears that there is little relation between the monthly changes in spearfish 

 catch rates in the two areas. 



For the principal species in the catch, the two sea areas appear to be related, but in 

 general the fishing seasons in this sea area appear to be about 1 month earlier. 



It was stated that there appears to be little relationship in the case of the spear- 

 fishes. If we look at the monthly composition of the catch, we see that in this sea area throughout 

 the year striped marlin are more abundant than broadbill. In the area between 160 and 170 E. , 

 the broadbill increase in numbers in the winter, equaling the striped marlin arourd December and 

 predominating thereafter. However, in this sea area also there is a clearer tendency for the 

 broadbill to increase in the winter so that the two sea areas are in agreement in this trend. 



125 



