Consequently, as a trend, it can probably be said that for each 10 of 

 longitude one moves eastward the surface water temperature at which 

 the catch rate mode appears is lowered by 1 C. 



2. Making the same sort of comparison for the waters between 

 35 N, and 40 N. , the modes appear: 



a. At 17°-18°C. between 140°E. and 150°E. 



b. At 18°-19°C. between 150°E. and 160°E. 



c. At 17°-19°C. between 160°E. and 170°E. 



d. At 17°-19°C. between 170°E. and 180°. 



Thus it is difficult to see any difference between areas, although the 

 temperatures appear to be sonnewhat higher in the central part. 



As a general trend over the whole sea area, the catch rates are 



higher south of 35 N. and the range of water temperatures is broader, 



while north of 35 N. the range is narrower, however, between 170 E. 



-O o 



and 180 the contrary is true, with good fishing shown north of 35 N. 



in a broad range of surface water temperatures. 



Z. Kinan Sea Area 



In December fishing grounds are clearly developing in this sea 

 area, where in November no albacore appeared at all. Fishing is still 

 sparse here in December, but unit areas with catch rates above 1.0 are 

 seen at 30 N. to 32 N. , 134 E. to 137 E. Fishing in this area becomes 

 active fronn January on, and it is an innportant fishing ground for small 

 and medium-sized vessels. 



Table 15 shows water temperatures for this area based on 

 oceanographic observations made by the Hyuga Maru in 1952, 



51 



