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MONTH 

 STATIONS 



HOOKS 



Figure 17. --Albacore fishing conditions 

 in each month (30 to 35 N. 

 140° to 150° E-.) 



Monthly changes in 

 the fishing conditions in the west- 

 ern Pacific north of 20 N. lat- 

 itude in the period from Novem- 

 ber to March, which is the main 

 fishing season, cire shown graph- 

 ically in the appended charts 

 Ua-e. 



In chart a (November) 

 there appears to be an area of 

 rather dense distribution 200 

 miles from east to west and 300 

 miles from north to south cen- 

 tered at 35° N, latitude, 150°E. 

 longitude. There is no area of 

 active fishing to the westward, 

 nor does any area with high 

 catch rates appear to the east- 

 ward as far as the vicinity of 

 150° E. longitude. East of 165° 

 E. in the vicinity of 30° to 40 N. 

 catch rates Jire high everywhere 

 and a dense occurrence of alba- 

 core is indicated. 



In chart b (December) the fishing grounds of the area centered around 150 E. are 

 greatly extended compared with Novennber. There ig a series of excellent fishing grounds ex- 

 tending to the southwest from the vicinity of 38 N. to an area southeast of Hachijojima at about 

 32 N. , 141 E. Farther to the west there is an excellent but completely isolated fishing ground 

 across the Izu Islands and south of Shiononnis'aki in the vicinity of 30 N. latitude. A tendency can 

 be seen for the fishing grounds to broaden southeastward from the vicinity of 150 E. , and the 

 fishing is good over an extensive area along the parallel of 33 N. between 140 and 155 E. 

 longitude. The center of the fishing grounds which appeared eaist of 165 E. in Novennber has 

 moved slightly to the southward and these grounds have extended towards the west, so that in 

 terms of catch rates alone the boundary with the fishing grounds which appeared centered around 

 150 E. longitude has become completely obscured and the whole eirea centered around 35 N. 

 latitude has become a good fishing ground. 



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In chart c (Januju-y) the center of the fishing grounds which were centered around 150 



E. longitude has shifted to the southwest to the vicinity of 29 to 33 N, , 143 to 147 E. In 

 December the vicinity of 35 N. was the center of a fishing ground, but in January fishing has be- 

 come remarkably poor north of 35 N. The isolated fishing ground which appeared in December 

 south of ShionomisaM has become greatly enlarged and the catch rates are improved over those of 

 December. East of 150 E. longitude there is little difference in the fishing situation from one 

 area to another, the catch rates being everywhere about the sanne. Within the region for which 

 we have data east of 150 E. , the center of distribution has gradually moved southward, and east 

 of 175 E. , the center of distribution is south of 30 N. latitude. 



When we conne to chart d (February), we have much fewer data than we had for 

 December and January, but on the whole there appears to be a tendency for the good fishing 

 grounds to be isolated or scattered. On the west, the fishing ground south of Shionomisaki has 

 beconne even more extensive than it was in January and the fishing is good there. Another fish- 

 ing ground with rather high catch rates has appeau-ed about 100 miles south of the Izu Peninsula, 



and another region of fadrly good catch rates can be seen to the east of the Izu Islands in the 



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vicinity of 31 to 34 N, , 141 to 142 E. The fishing ground which was centered at 30 N. , 



143 



