What has been said here does not nnean of course that the work of research vessels 

 in the past was completely without significance. As will be set forth in the following, it is 

 possible in some degree to learn the characteristics of the various fishing grounds. It has, 

 however, been possible to learn only very little concerning the movements of the schools and the 

 accompanying changes in fishing grounds and fishing seasons, questions which it was hoped at 

 first would be clarified by this study. 



A. Indian Ocean Region 



The waters to the south and west of the Greater and Lesser Sunda archipelagos will 

 be described as the Indian Ocean Region. Almost all of the data for this area were gathered by 

 the training ship Hakuyo Maru of the Fisheries Institute of the Ministry of Agriculture and 

 Forestry and the research vessel Haruna Maru of the Fisheries Bureau of the Ministry of 

 Agriculture and Commerce. In addition the fisheries research vessel Shonan Maru, of the form- 

 er Formosa Government-General smd the nnothership-type tuna fleet of the Tobu Fisheries 

 Connpany operated experimentally in this region. There is also a snnall amount of data for the 

 area from the research vessel Zuiho Maru of the South SesiB Government-General. 



It appears that before the war some Japanese fishermen were trolling out of 

 Singapore, but there was no real tuna fishery operated either by Japanese or by the natives of 

 the region. During the war many fishing boats operated in this area in order to supply food for 

 the troops. They appear to have been fairly successful, but they left no records at all. 



Nothing is known of the situation since the war. As the natives have no knowledge or 

 experience of this type of fishery, it cannot be thought that there is any possibility at present of 

 their operating a longline fishery. Consequently, it is believed that these waters remain almost 

 completely virgin grounds for the tuna fishery. However, as has already been said, it appears 

 that a start has already been made in Australia, £uid Ceylon and Pakistan also seenn to be show- 

 ing an extraordinary interest in fisheries, so the waters of this region will probably be devel- 

 oped as fishing grounds in the not far distant future. 



This region has been subdivided as follows: 



1. Waters around the Andaman and Nicobar islands. 



2. The west coast of Sumatra. 



3. Waters around Java. 



4. Waters around the Lesser Sunda archipelago £ind Timor. 



In addition to these four areas, the HsikuyO Maru made a survey in the vicinity of 



4 N. latitude, 75 E. longitude, but as the data were few they have been onnitted from consid- 

 eration. 



o o o o 



1. Waters around the Andaman and Nicobar islands (6 to 15 N., 90 to 97 E. ). 



As we have very few data concerning oceanographic conditions in this sea area, their 

 details are unknown. In this region the year, is divided into two seasons, in one of which the 

 northeast winds blow continuously, while in the other southwesterly winds prevail. The former 

 corresponds to the winter of the Northern Hemisphere and the latter to the summer. These 

 seasonal changes are accompanied by marked differences in oceanographic conditions. 



The currents during the period from July to September when the southwesterly winds 

 are at their strongest axe roughly as follows. There is a current which flows in the vicinity of 



5 N. and this current divides into two branches to the west of the northern tip of Sumatra. One 

 branch flows to the southeast along the west coast of Sumatra; the other flows north-northeast 

 along both sides of the Nicobar and Andaman archipelagos. The speed of these currents is 

 about 0. 5 to 1 knot. 



42 



