UJ 



h- 

 < 

 q: 



X 



o 



H 

 < 

 O 



Figure 27 is a curve 

 of monthly catch ratea for 

 yellowfin tuna in the area south 

 of Japan between 25 anci 30 N., 

 130° and 140° E. Data are 

 completely lacking for August 

 ajid September. As may be seen 

 in the figure, the catch rates are 

 much lower than in all of the sea 

 areas previously treated. There 

 is a very outstanding peak in 

 October falling off sharply from 

 November on. There are no 

 marked changes from January to 

 March, the low point of the year 

 being reached in April. The 

 catch rate is low in May, but a 

 more or less conspicuous peak 

 does appear. The October high 

 coincides with that of the South 

 China Sea, while the May peak 

 coincides with that of the equa- 

 torial region. On the whole it is 

 assumed that the form of the 

 curve approximates that for the 

 South China Sea. 



Figure 25. --Yellowfin fishing conditions by months, 



Palau waters (7 to 8° N. , 133° to 135° E 



) 



6~ 



Ul 



< 



a: 



X 



o 



< 

 o 



Figure 26. --Yellowfin tuna fishing conditions by 

 months. South China Sea 



Figure 28 shows the 

 monthly fishing conditions for 

 yellowfin in the area from the 

 MariaJias Islands to the south- 

 ern part of the Ogasawara archipelago. 

 Data are lacking for the month of 

 October. 



As the figure shows, the 

 maximum catch rate of the year for this 

 area appears in December. Fronn Janu- 

 ary through February the catch rate drops 

 off sharply, with a low point in the latter 

 month. In March and April it shows a 

 tendency to rise somewhat, and in May a 

 rather conspicuous secondary peak ap- 

 pears. Thereaifter the catch rate again 

 declines and reaches the low point of the 

 year in July. As we have no data for 

 October, it is not known whether a peak 

 would appear in that month as it did in the 

 various other sea areas. Comparing this 

 figure with the curves for the various 

 other sea areas already described, we 

 find thenn completely alike in respect to 

 the peak appejiring in May. From the 

 trend of the curve, it is difficult to think 

 that a peak would appejir in October, and 

 in this respect the curve differs from 

 those for other areas. Except for the 



151 



