and juvenile forms of the tunas is extremely poor, and hardly 

 anything is knovm about their ecologyo Consequently they are not 

 the object of a fishery at alio Even if their ecology were made 

 clearly knownp it cannot be thought that a fishery would grow up 

 which would make the larval and juvenile fish its objectiveo After 

 alls, it is possible to think of fishing as a sort of thinning out 

 of a crop. In actuality j, up to the present the tunas seem to show 

 absolutely no evidence of overfishing^ The yearly variations m 

 the catch are thought to be caused mainly by changes in oceanographic 

 conditions o We know of absolutely no data that would show that 

 cessation of fishing had any effect upon the population of these 

 fisheso 



In order to afford a contrast with table 5j some tuna catch 

 statistics are given in table 6„ 



Table 6 



Comparison of Tuna Catches^, Including Spearfishes 

 (statistics of the Ministry of Agriculture and Forestry) 



If this table is compared with table 5j, it will be noted that 

 the variations in the amount of the catch from year to year are 

 greato In spite, however^ of these marked variations, there is 

 clearly a general tendency for the catch to increase gradually.. It 

 is to be regretted that the number of vessels engaged in the fishery 

 is not accurately known, but if the assumption is made that the boats 

 working in the skipjack fishery all engage in the tuna fishery during 

 the winter^ we get approximately the following situationo 



72 



