Fishing conditions in the two regions delimited on this 

 basis are, as table 14 shows, conspicuously different o As is 

 clear from the table, the catch rates for big-eyed tuna and 

 spearfishes hardly differ at all, but the catch rate for yellow- 

 fin in the northern area is less than half whuc it is in the 

 southern, and on the whole the catch rates north of the line are 

 remarkably low„ This maans that if the two areas are compared 

 as fishing grounds, the northern is far inferior to the southerno 



As there are very few data on which to base a judgment as 

 to whether the fish in the tv^o areas are of different age groups 

 or whether it is simply a case of the same groups having a 

 different density of distribution in the two areas, this point 

 i s unknowno 



A consideration of data obtained in the Indian Ocean 

 region reveals some phenomena of extraordinarily deep interesto 

 The data from this region are limited to the period from Noventier 

 to February, so the year-round situation is completely unknown, 

 but some discussion is possible of the relationship between the 

 ocean currents and the distribution of the tuna during the 

 season of northerly winds o 



The following table gives the data from the Indian Ocean 

 region arranged generally in order from north to south without 

 regard to the year of the survey. 



98 



