respectively. The values for the black tuna and yellowfin catch rates are so low as to be 

 vestigial. 



If the section between 150 and 160 E. is divided into five parts by 2 of longitude, 

 and fishing conditions within each of the resulting sections are compared, the results are as 

 shown in the following table. 



o o 



Table 87, -- Fishing conditions by sections (30 to 35 N. , 



150° to 160° E, ) 



Black tuna auid yellowfin are extremely scarce, so no accurate conclusions can be 

 drawn on the basis of this much data, however, it appears that black tuna tend to be more abun- 

 daxit to the westward, while yellowfin seem to be more abundamt in the central portion. Bigeye 

 tuna are taken rather uniformly everywhere, but they are somewhat scarcer at the western ex- 

 tremity and their catch rates appear to be high in the east and low in the west. Albacore are 

 abundant in the area centered around 155 E. and show fairly high catch rates between 158 and 

 160 E. Spearfishes are abundant west of 156 E. and their catch falls off sharply to the east- 

 ward. 



The following table shows the fishing situation by months for this sea area as a whole. 

 The data are very unevenly distributed in time and there are only a few data for May and July, 

 while data are completely lacking for the other summer months. Consequently it is impossible 

 to know the changes in the fishing conditions throughout the year, but looking at the table it can be 

 seen that black tuna are not taken fronn Mairch to November. They are taken sporadically from 

 December to February, and their highest catch rates are found in December. Some yellowfin 

 are taken from the end of October to December, and their highest catch rates appear around 

 October. No very marked changes in the bigeye tuna fishing situation can be detected, but they 

 are more abundant in the winter season from October on with r^her high catch rate values for 

 October and December. The albacore increase suddenly after December, and reach their high- 

 est catch rate of slightly more than 8.0 in February. They appear to be scarce in the summer, 

 but as they show a catch rate of slightly more than 3.0 in July there appears to be considerable 

 possibility of expecting some catch at times. The spearfishes show their maximum catch rate 

 of slightly under 2. in October, and thereafter with the passage of time they tend to decrease 

 gradually. 



If these secLsonal changes in fishing conditions are compared with the sea area 

 adjacent on the south, a thoroughgoing comparison is innpossible because of the lack of data 



and 

 The highest bigeye 



o _o 



between 25 and 30 N 



o o 



There is no record of black tuna being taken between 25 ajid 30 N. 



although yellowfin are taken almost throughout the year, the amount is small. 



119 



