The number of boats ent«ring porti, the number of fish landed.^ and the 

 weight of landings, averaged by ten-day periods. (Figure l) show that tha 

 peak season is from the middle ten days of January to the first ten days of 

 Aprilj, and that during this period the fishing falls off somewhat from the 

 last ten days of February to the first ten days of Wrcho The fact that in 

 general the fishing situation parallels the abundamce or scarcity of schools 

 on the fishing grounds can be seen from the average number of fish landed 

 per boat per trip as plotted for each ten-day period (Figure 2j, above) o 

 This means that the peak season is when the schools are plentiful, and that 

 during the period from the last ten days of February to the first ten days 

 of March the schools temporarily decrease in numbers o Because the number of 

 boats fishing is very small^ it is not certain,, but it appears that from the 

 middle ten days of ^y on the schools increase o Hcwever^, if we look at the 

 average body-weight plotted by ten-day periods (Figure 2^, lower), the period 

 from the last ten days of February to the first ten days of iiiarch represents 

 a shift in the average body-weight from about 46 kan to about 52 kan, and the 

 period from the last ten days of April to the middle ten days of May shows 

 a shift of the average body-weight from about 40 to about 47 kanc This can 

 still be said even though we try to split the chauages in average body-weight 

 into long-time changes throughout the season (trends) and short-term changes 

 (deviations) (Table 1^ Figure 2)o Then if y is taken as the average body- 

 weight for the ten-day period (in kan J , and x is the ordinate of the period, 

 with the period in which the first catch was made as the base pointy the 

 trend for Aburatsu, with the middle t»n days of December as the first period, 

 is y s 54o29 - 0t,87Xj, and for Nango, with the third ten days of December as 

 the first periodj, it can be shown as y s 49,50 - Oo32.Xo 



To summarizes, in the black tuna which migrate into the Satsunan sea 

 area from the middle ten d ays of December to the first ten days of June of 

 the following year, the general trend is from schools of larger fish to 

 schools of smaller fisho If, however^, we examine this in further detail, 

 we find in the early part of the season from the middle ton days of December 

 to the first ten days of January a migration of a group of larger fish with 

 an average weight of around 55 kan o In the first half of the peak season,' 

 which is centered around the first and second ten-day periods of February, 

 there is a large group of smaller fish with an average weight of around 

 45 kan,, and in the second half of the peak season„ which is centered around 

 the~middle and last ten-day periods of Marchj, there is a large group of 

 larger fish with an average weight of around 52 kano In the last ten days 

 of April for a time there is a group of smaller fish under 40 kan , and after 

 that as the end of the season approaches a group of smaller fish of about 

 47 kan again appears <, 



In conclusion we wish to express our heartfelt thanks to Dr^ Morisaburo 

 Tauchi, Professor in the Fisheries Institute, for taking the trouble t£ read 

 the manuscript, and to the Fisheries Associations of Aburatsu and Nango, 

 which spared no labor in compiling the daily reports on the fishing situationo 



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