Table 12 Catch at Various Depths (1936, Shonan Maru) 



The % shown in these tables is the ratio per 100 hooks. In addition 

 to the catches indicated in Table 12 in 1936 two albacore were taken at 

 100 m. 



Looking at these tables it appears that the deeper one goes the 

 better the yellowfin catch is, while the big^eyed tuna tend to occur at 

 somewhat lesser depths than the yellowfin. In general the fishing for 

 the spearfishes is better at the shallow levels, and the sharks are taken 

 in greatest numbers on the shortest branches. 



In the survey made by the Shonan Maru in the East Philippines Sea 

 branch lines of 80m and 100m were used„ As a result it was found that 

 both for tunas and spearfishes (almost exclusively yellowfin and black 

 marlin) the 100m lines fished somevriiat better. 



The results of investigations in the Celebes Sea were as followsj 



Table 13 Catch at Various Depths (Celebes Sea, Shonan Maru) 



a. 1931 



Depth (m) ^5 68 91 129 

 Catch rate (56) 4o2 lc7 2,1 5«9 



bo 1932 



Depth 23 90 113 136 160 

 Catch rate(%) 3o9 7c3 4.7 5.1 6.0 



c. 1934 

 (a) Eastern area (125° - 130°E) 



Tunas Spearfishes 

 Depth Number % Number % 



35 



