o o 



Table 61. --Fishing conditions by months (20 to 25 N. 



150° to 180° E.) 



Table 62. --Fishing conditions by months (25 

 150° - 180° E.) 



30° N. 



Month 



Num- 

 ber of 

 hooks 



Num- 

 ber of 

 fish 



Black tuna 



Catch 



rate 



Yellowfin 



Num- 

 ber of 

 fish 



Catch 

 rate 



Bigeye 



Num- 

 ber of 

 fish 



Catch 

 rate 



Albacore 



Num- 

 ber of 



fish 



Catch 

 rate 



Spearfishes 



Num- 

 ber of 

 fish 



Catch 

 rate 



Total 



Num- 

 ber of 

 fish 



Catch 

 rate 



Jan. 



Feb. 



Mar. 



May 



July 



Dec. 



108,878 

 86,72 



125,941 

 1, 300 

 1, 000 

 2,996 



20 

 10 



2 



1 







2 



0.02 

 0.01 





 0.07 





 0.07 



720 



502 



289 



2 







5 



0.66 

 0.58 

 0.23 

 0. 15 





 0. 17 



6,337 



3, 142 



4, 319 









 2 



5.82 

 3.62 

 3.43 









 0.07 



187 



160 



197 







6 



32 



0. 17 

 0. 19 

 0. 16 

 0. 30 

 0.60 

 1.07 



7,264 

 3,815 

 4,812 



7 



6 



41 



6.67 

 4.40 

 3.82 

 0.52 

 0.60 

 1.38 



In general the catch rate is low in the summer and high in the winter with the 

 maximum in January. Although the data can hardly be said to be adequate, the yellowfin catcl 

 rate for November and Janur.ry is over 1.0. The bigeye fluctuate in approximately the Scime 

 fashion as the yellowfin. Albacore have their peak catch rate in Jjuiuary; spearfishes are most 

 abundant from January through March with their peak in February. Data for the summer are in- 

 adequate, but it appears that catch rates increase from May through July. 



If this is compared with the southern part of the Ogasawara Islands area [see table 56), 

 the trends of increase and decrease for the yellowfin are roughly in agreement, although the 

 catch rate values are different. Bigeye tuna and albacore are Jilso quite similar, and approxi- 

 mately the same sort of trend is shown for the spearfishes. 



Table 62 shows changes from month to month in the fishing conditions in the northern 

 section (25° to 50° N. ). 



Fishing is good from December on, with the highest catch rate in January. During 

 February and March catch rates fall off gradually. For the summer there are only a few data for 

 May and July and no sort of analysis can be given with just these data, however they appear to 

 show that fishing is extremely poor. 



Considering the individual species, black tuna are taken very rarely in February and 

 March; yellowfin appear to be taken throughout the year but in such numbers that it is hardly 



95 



