indicated for the size of the yellowfin to be greater in the north jind smaller in the south. In 

 other words, in the south the catch rate is high but the fish are small, while in the north the 

 catch rate is low and the fish are large. 



Looking at the changes in the fishing conditions by seasons, within the period 

 December- January there is clearly a tendency for the catch rates to rise gradually with the 

 passage of time. From January 27 to 31, 1932, the catch rates of the Hakuyo Maru showed an 

 astonishingly high average of 19.65, and on the 27th and 28th of January 1930, the catch rates 

 were also high, being 16.67 and 12.33 respectively. 



This trend of increase and decrease in the catch rates with the season is similar to 

 that which can be seen in the waters off the west coast of Sumatra which adjoin this sea area to 

 the south, and therefore can be thought to indicate the migrational pattern of the schools in the 

 northeastern part of the Indian Ocean. As will be detailed later, in the northern part of the 

 Sumatran waters the catch rates gradually increase from November on, showing a tendency to 

 a continuing increase until at least February. 



The foregoing is a general outline of fishing conditions for tunas and spearfishes. 

 The Hakuyo Maru's reports contain absolutely no records concerning sharks, which follow these 

 fishes in importance. According to the reports of the Haruna Maru, the catch rate for sharks 

 wjia 1.84. This means that at that season sharks were taken at the rate of about 2 for every 100 

 hooks fished. Daimage to the catch by sharks appeeirs to have been rather great, but we have no 

 detailed information on it. Miscellaneous fish mixed in with the catch were skipjack, dolphin, 

 and cybiids, but they were few in number and of little significance. 



The gear used by the Hakuyo Maru had branch lines of two different lengths, the 

 construction being as follows: 



Type of branch line Number of branch lines Length in feet 



Long branches 

 Short branches 



2 



4 



99 

 30 



The length of the float lines was 90 feet. The following table shows the catch made by 

 the long and short branch lines of this gear. 



Table 11. --Fishing results by type of branch line 

 (Hakuyo Maru, waters of Andaman and 

 Nicobar islands) 



The percentage figures in this table are the proportion 

 of the total catch taken by each type of branch line. 



As the foregoing table shows, the long branches gave nnuch better results than the 

 short branch lines. Indeed, if we compare the number of hooks actually used on each type of 



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