so 



60 



Figure 1. --Length frequency of the albacore caught in the 

 northwestern Pacific during the longline 

 season (indicated by permillage). 



The data were gathered by the Nankai 

 Regional Fisheries Research Laboratory— by 

 working on fish landed at markets during the 

 period. From 1948 to 1951 measurements 

 were taken of as many fish as possible from 

 the maximum possible number of boats; in 

 1952 n-ieasurements were taken on a sampling 

 ratio of 0. 1 of the fish from 0. 5 of the voyages. 



Before entering upon the text of the paper, 

 the author wishes to express his gratitude to 

 Director Nakannura and Mr. Yabe for their 

 assistance, to the various personnel of the 

 High Seas Resources Section who collected the 



— Measurements taken during this period 

 were as follows: 



data, and to Miss Michiko Momota, who 

 processed the data. 



Body Lengths of the Schools of Albacore 

 Migrating Southward in the North Pacific 



Figure 1 shows by years fronn 1948—' to 

 1952 the length composition in permillages of 

 albacore landed from this area. The length 

 used is the fork length. The length range of 

 albacore taken by longlines in these fishing 

 grounds is very broad, extending from about 50 

 cnn. to 120 cm. In the measurements taken 

 over a period of 5 years the snnallest specimen 

 was 37 cm. and the largest 121 cm. in length. 

 Fish longer than 120 cm. were extremely rare 

 and in 5 years only 5 were encountered. 



The length distribution curve is extremely 

 complex, with either several modes appearing 



2/ 



— The albacore longline fishing season 



extends each year from November to March of 

 the following year (this report covers to Febru- 

 ary). The "year 1948" as used in this report 

 mean* from November 1948 to March (for the 

 purposes of this report to February) of 1949, 

 and so on for the other years. 



