60 ro 83 30 100 110 l?0 50 60 70 80 90 100 

 130-HO'E I«0-I50'E 



1352 1 



ro 80 go 100 no i2q 



30- H'H 

 1349 I 



Figure 10. --Comparison of length frequencies 

 of albacore taken at 130°- 140 E. and at 140 - 

 150°E. 



Table 10. --Albacore catch rate frequencies, by years, in the area 

 of 12°N.-25°N., 128°E.-140°E. "M" is the average catch rate 



As table 9 shows, the catch rates vary considerably from year to 

 year. The year 1951 was a particularly active one on this fishing ground, 

 auid many fishing vessels concentrated in this area. It is difficult to make 

 any definite affirmation because of a lack of continuing data, but it is 

 thought that there may be an appearance of high catch rates every other 

 year. 



The size compo8ition_of the c_atch is as shown in table 11, with the 

 average weight above 6 kan Jj)0 Ibs^/ 



Table 11. --Size composition of albacore taken on the Okinotorishima 

 ground, in percentages. Lower figures are weights in kan <k. )= 

 8.27 lbs. 



75 



