appear around the middle of October, far to the east of 

 Kinkazan and move day by day to the south, with the fishing 

 improving steadily,, Generally from November to Janiiary there 

 are good fishing grounds from 2^)0 to 600 miles east of 

 Kinkazan and Cape Nojima, Ordinarily these groxmds appear 

 in February from 200 to 600 miles to the SE and SSE of Cape 

 Nojima, and in March, they are usually 300 to 500 miles SE 

 of Cape NojimHo At times, nowever, there may be two centers 

 of fishing grounds in the same months The peak of the season 

 is usually in January and February, although in some years 

 very good fishing is had in Decenber or in Marcn,, After the 

 first of April the catch declines sharply, in part because 

 the fishermen at this time turn to the skipjack fishery^ 



Considering next the relationship between water tenpera- 

 ture and fish catch, in October at ten^jeratures of 22° to 23° 

 some fish are taken but the amount is inconsiderable o In 



» 



November 19° is considered the most favorable temperature 

 and from Decenber to March, the period including the peak 

 season of the fishery, the most favorable fishing tenperatures 

 are everywhere centered around l8°o A general outline of this 

 relationship is shown as follows? 



(Example drawn from the winter of 1933- to the spring of 1932) 



Range of water tenperatures at which fish are taken — 

 15° to 23° 



Range of location of good fishing grounds — lii2° to l5l°Eo, 

 30° to 37°N, 



Range of favorable water temperatures — ■ 17° to 19° 



Seaeon of greatest catch — January and February 



Ihere appears to be little variation in the relationship 

 between fish catch and v/ater tenperature from year to year, 

 (Considering the movements of the fishing grounds as a whole, 

 they are at their farthest south in March, there thus appear- 

 ing to be a close relationship between the movements of the 

 isotherms centered around 18° and the movements of tte fishing 

 grounds o ) 



(b) Oceanographic conditions and the offshore fishing grounds 



!Ihe Kanan Maru of this prefecture sailed from Ajihama 

 January $, 1932 and fished in the vicinity of 152°UO« to l57°Eo 

 longitude, 31°28' to 33°15'No latitude, Ihis vessel took 99 

 albacore, 67 big-eyed tupa, 11 large skipjack, 5 striped marlin, 



11 



