Table 66. --Oceanographic conditions in the vicinity 

 of 30° N. , 134° 30' N. 



Table 67. --85 miles south by east of Gozamisaki 



From the foregoing it appears that during the period when the fishery was in a 

 stabilized condition, with no great difference in the number of fish taken from year to year, there 

 were schools made up of approximately the same sizes of fish migrating into the grounds every 

 year at a more or less definite season. However, as the size of these migrating fish increased, 

 their numbers declined abruptly, and finally a condition was brought about where no fish were 

 taken at all. 



As explained in the foregoing, hardly any black tuna are now taken, but a certain 

 number of bigeye tuna and spearfishes are caught at present, the bigeye tuna being the most 

 important. 



In the west coast waters of Kyushu, which adjoin this sea area on the west, the catch 

 is almost entirely composed of spearfishes. The fishing ground for the most part is along the 

 100-fathom line in the East China Sea. The best known fishing ground is in the vicinity of Saishu 

 To (Quelpajrt Island), but some fish are also taken across the Tsushima Strait in the southern 

 part of the Sea of Japan. In August and September the fishing grounds are centered around Saishu 

 To, but thereafter with the passage of time they gradually shift to the southward. 



Spearfishes are abundant from the waters around Tanegashima north to the region of 

 the Hyuga Nada, and the harpoon fishery in this area is at its peak from April through June. 

 Farther to the eastward, between the waters of Tosa and the Kishu region, the black tuna catch 

 declines sharply and albacore become the most innportant item in the catch. Next to the albacore, 

 bigeye tuna are the most abundant, and at certain seasons some yellowfin aind spearfishes are 

 taken. Farther to the eastward in the Izu Islands region, the makeup of the catch is again dif- 

 ferent, spearfishes being the most innportant element in the catch here and surpassing the tunas. 



Thus the connposition of the catch is different in the different sea areas, and fishing 

 is carried on using gear of different construction. It may be thought that the differences in the 

 catch are due to the differences in the construction of the gear, but the actual truth is probably 

 that differences in the distribution of the species have brought about the chajiges in the construc- 

 tion of the fishing gear. The foregoing refers only to the longline fishery, and in actuality 



99 



