Table 52. --Fishing conditions by months (25 to 30 N. , 

 130° to 140° E.) 



Note: There are no data for August and September. 



Black tuna are most abundant from January to March, amd they appear to increase 

 again somewhat around May. Fluctuations in fishing conditions throughout the year are not clear 

 because data are lacking for August ajid September, but within the period covered by the table 

 some black tuna were tciken in all months except July and October. In general yellowfin are ex- 

 tremely scarce, with a catch rate of slightly more than 1.0 in October declining gradually from 

 November on. Bigeye tuna are most abundant fronn October through December and show their 

 highest catch rate of the year in the latter month. Albacore are taken only during the winter and 

 the catch rate is at its peak in March. Spearfishes are more numerous in the summer, being 

 most abundant around May and June. In the winter their catch rate increases somewhat in 

 January and February. In general catch rates are higher in the summer, the nnain reason being 

 that the catch of spearfishes increases. 



Comparing these conditions with the Okinawa area adjoining on the west, a 

 particulcirly marked difference can be detected in the black tuna fishing. That is, in the Okinawan 

 region black tuna are taken only fronn April to June, with their highest catch rates in May. In 

 this sea area there are, as explciined above, two seasons for this species, the main one being 

 from January through March, with another separate peaik in the catch rate in May. It is natu- 

 rally hypothesized that the schools which appear in May are the same as those which appear in 

 the Okinawan area, but the relationships of the schools which come from January to March are 

 not clecir. It is thought that almost no difference can be seen in the two areas as regards fluctu- 

 ations in fishing conditions for tuna species other than the black tuna. It appears, however, that 

 in some cases there may be, depending on the species, more or less of a lag in the time of the 

 peak season. 



Regarding the spearfishes, which are the most important catch in both these of sea 

 areas, it looks as if the seasonsil chamges in fishing conditions are of completely identical pattern, 

 with the catch rate at its highest from May to August. Unlike the tunas, the spearfish catch rates 

 are always fairly high throughout the year and there is no season at which none are taken. 



In order to compare fishing conditions from east to west, the area has been divided 

 into five parts by 2 of longitude and table 53 gives ithe fishing situation for each of these 

 sections. 



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