Vo Summary 



The items detailed above may be summarized as follows s 



Cl) The drift-net fishery for tuna in Hokkaido began in 1905 ^^'ith the inci- 

 dental capture of tuna in drift nets set for sharkj and at present has 

 reached a flourishing condition at Kushiro and Urakawao The establishment 

 of the long-line fishery is comparatively recentj dating from 192b^ The 

 set-net fishery is oldest at Funkawan, and was started at Etorofu Island 

 in 1917 o 



(2) The first catches in the driftH:iet fishery are made in the latter 

 part of June (June 27 on tiie average) near Erimosaki„ The main season is 

 from the middle of July to the latter part of October, with the peak in 

 August, and fishing ends in November (November U on the average, but much 

 later in recent years). The grounds are in the waters east of Urakawa 

 and lie comparatively close to the coast. The season in the long-line 

 fishery is from August to December, and the grounds are in the waters 

 west of Erimosakio The set-net fishery in Funkawan is divided into two 

 seasons o 



The Etorofu Island set nets catch the largest fish, followed by those 

 taken in the Funkawan set nets at the end of the season o The fish taken 

 in the long-line fishery are larger than those taken in the drift-net 

 fishery. In the Kushiro drift-net catch many large fLsh are taken at the 

 beginning of the season, the average weight being kl^O pounds or more, but 

 gradually the number of medium and small tuna comes to exceed that of the 

 large fish and the average weight comes to be 80 to 160 pounds. The number • 

 of large fish increases again somewhat at the end of the season » 



(3) The following table shows a summary of the fishing situation and 

 peculiar oceanographic phenomena during the past 11 years, /See next p&ge^J 



CU) The paths of the tuna schools migrating to the Pacific coastal waters 

 of Hokkaido appear to follow these three routes? (A) those fish which are 

 drawn by the warm Tsugaru current to Shiriyasaki and thence enter Funkawan, 

 (B) those which move northward along the third branch of the warm current 

 from off Erimosaki through the waters off Kushiro to the Etorofu Island 

 area, and those which follow the Hitaka coastal waters from Erimosaki and 

 enter Funkawan, and (C) those which reach the waters off Kushiro along the 

 second branch of the warm current and then move on farther north, Vllhen 

 they go south in the fall their routes are (A) along the coast from 

 Erimosaki toward the Funkawan and Ezansaki areas, (B) from Erimosaki 

 directly to the waters off Kamaishi, and (0) southward off shore with 

 the retreat of the second branch of the warm current. The above may be 

 called localized migrations in which the schools remain for a considerable 

 length of time off Shiriyasaki, off Eaansaki, off Erimosaki, and off Kushiro. 



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