(2) Albacore Migrating Southward from North Pacific 

 Areas Across the Subtropical Convergence 



In the waters east of the line of the Izu, Ogasawara, and Mariana 

 archipelagoes ajid north of 10 N. latitude from September to February- 

 large alabcore are taken in some nunnbers everywhere, but the catch rates 

 rise above 1. only in extremely rare cases. Then in March between 15 N, 

 and 25 N. the albacore catch rates rise, and cases of rates above 1.0 

 appear in considerable numbers. Data from east of 155 E. are very few, 

 so the trend there cannot be fully seen, however, it is thought to show the 

 same pattern as the areas west of 155 E. It has been pointed out that on 

 the North Pacific fishing ground the positions at which the albacore stop 

 their southward migration are thought to be farther south, the bigger the 

 fish are. The albacore which appear in March between 15 N. eind 25 N, 

 are, as shown in table 10, extremely large, and it is thought that these 

 albacore continue their southward movement aiter the small albacore in 

 the North Pacific fishing ground have stopped between 26 N. and 32 N. , 

 and that this continuing southward movement brings them into this sea 

 area. 



Table 10. --Length composition (numbers of 

 fish) of albacore landed from 20 -25 N, , 

 145°-150°E. Weight in kan 



Since the Subtropical Convergence in March is between 22 N. and 

 24 N, , this means that the schools of albacore break through the conver- 

 gence and continue on south of it. These albacore are of no great impor- 

 tance as the objective of a fishery, but as a link between the albacore 

 distributed north and south of the Subtropical Convergence, and from the 

 standpoint that they are thought to have sonne connection with spawning, 

 they are believed to be important ecologically. 



(3) South Seas Grounds 



In general, the fishing is at an extremely low ebb. West of 140 E, 

 there is almost no trace left of the Palau fish, and the albacore in the South 

 China Sea have also disappeared. East of 140 E. there are still occasionally 

 cases of catch rates above 0. 1. 



ill 



