Katnezo Uehara receiTed a subsidy from the Government-General in 1925 

 and operated a miscellaneous fishery, taking s^dagatsuo / Auxis thazard_7 

 inside the reef„ Beginning Icl 1926 he planned a skipjack fishery using 

 canoes, but seeing the results obtained by the Hakuo Marn^, he received a 

 grant'='in=aid from the Government-General in June 1928 to construct a 

 powered fishing vessel and began fishing f-^r skipjack and manufacturing 

 dried skipjack sticks. By March 1929 Tamagasuku and Kaneshiro's two boats 

 had appeared and were fishing successfully o 



A Tuna Survey in Falau Waters (Late 19i^0) 



The report of the tuna survey in Palau waters conducted by the Hakiio 

 Maru during early 1940 (April to September) was published in Volume 4j, 

 NOo 6 of this journal^ a report is hereby made on the later survey 

 (September 19/^0 to March 19-41) » 



This survey consists of 14. operations conducted from September 11,, 

 1940 to March 17, 194.1o The number of operations is the same as in the 

 earlier survey. A very small area southeast of Palau bounded by north 

 latitudes 7° 17' and 6*^ ^9" and east longitudes 134'"' 44" and 134^ 2.8' was 

 sur'-7eyed„ No investigation was made of the areas west or north of Palau, 

 The resultSj as shown beloWj were generally the same as those obtained in 

 the earlier survey. 



The minimum water temperature at the surface was 28„1 degrees and 

 the maximum was 29o8 degree So The water temperature of the present sur- 

 vey was 0.7 degrees lower than the minimum temperature of the previous 

 survey and 2„1 degrees lower than the maximum^ 



The water temperatuic ao the SO^raeter layer shewed a ininimum of 27ol 

 degrees, a maximum of 28„8 degreesj, and an average of 27o7 degrees. 



At the iOO-meter layer the water temperature showed an average of 

 21o4 degrees with a minimum of 16,4 degrees and a m.aximum of 24.o7 degrees. 

 The water temperature at the SO^meter layer, therefore, is about 1 degree 

 lower than the surface water temperature and at the 100=meter layer about 

 6„3 degrees lower than the 50-meter layer. 



Since the tuna longline used in this survey was constructed to fish 

 at the SO-meter layer; the water temperature suitable for tuna during 

 this survey period is believed to be from 27 to 23 degrees. 



Curre nt direction and velocity 



Of the 14 fishing tests conductedj the ninth fishing ground with the 

 highest catch ratio of 9<.44-» showed a current direction of SW/W and a 

 current speed of 0,'75 knots. The next highest catch ratio of 5,41 is 



22 



