hooks ares although their approximate position can be knowno As 

 the positions of a_ and b_ in the figure change, the position of c_ 

 will necessarily undergo various changeSo In order to do away 

 with this defect, the Sho"nan Maru employed gear in which there was 

 a float attached to each branch line to investigate the level at 

 which tuna were caughto The results are given in table 80 



Surveying the results set forth in table Sj, a - c, one can 

 detect a tendency for the catch rates for tuna in waters east of 

 Formosa to increase with increasing depthj, at least down to 100 

 meters o The spearfishes are caught in greatest numbers at somewhat 

 shallower depths, 50 - 60 metersj, while the catch rates for sharks 

 are highest at even shallower levels o 



Table 8 

 Fishing Situation at Different Depths 

 a)o East of Fomosaj Novo - Dec, 1^)35 (.'ih'onan Maru) 



bjo East of Formosa., Nov. - Deco 1936 (Sh'oiian llaru) 



60 2,160 22 I loO 



80 2,160 28 lo3 



100 12,160 ! 32 ! lo5 



Notes 



5 

 5 



2 



Oo2 

 Oo2| 



Ool 



18 



5 



5 



0„8i 

 I 



Oo2J 

 O02! 



4 po2 

 1 OoO 



boO 



16 

 5 



5 



0o7 

 Oc2 



Oo2 



42 

 9 



1 



(1) % indicates catch per ?l00 hooks. 



(2) In addition, 2 al'iacoro weie tal.en at 100 meters o 



c)„ East of Formosa, Deco 191)6 - Jebo 1937 (Shichisef. Maru) 



lo9 

 0o4 



OoO 



Notes % indicates catch per 100 hookso 



81 



