1928 o "-Fishing on the Kushiro drift-net grounds was poor in July and 

 August^ but good in Septembero In normal years the peak of the season 

 comes in Augustj, but this year it was in Septembero The end of the season 

 was delayed and the fishing grounds were near the coasto The schools 

 extended to the Etorofu Island areao Small tuna were numerous and the 

 average size of the fish was small » Ihe long-line grounds, centered around 

 Erimosaki and extending to the waters off Kushiro, afforded good fishing. 

 In November the set nets in ^unkawan had good fishing, and at the same 

 time there were dense schools in the Tsugaru Strait o The set nets at 

 Etorofu Island had good fishings 



1929 0— The Kushiro drift-net grounds had their best fishing in the 

 10-year period„ Ihe groimds did not extend east of Akkeshi and were close 

 in to the coast. There were few small tuna and the average size of the 

 fish was large o Long-line fishing was good on the grounds west of Erimosaki » 

 The catch of the set nets in Funkawan was small, and the set nets of Etorofu 

 Island had rather poor fishings 



I93O0— The Kushiro drift-net grounds extended over a wide area from 

 Erimosaki to the waters off Otchishisaki, and the fishing was moderately 

 good, with no concentrated groimdso There were many small tima and the 

 average size of the fish was small. The long-line grounds had extremely 

 poor fishingo Ihe set nets in Funkawan made good catches of small tuna 

 in Augusto The Etorofu Island set nets had poor fishing„ 



1933.0=- The Kushiro drift-net grounds were not as close to shore as in 

 the previous year and their northern end was at Shikotan Island, Ihe large 

 tuna were unusually large in size, there were few medium fish, and small 

 fish were very numerous. The average size of fish was the smallest in the 

 10-year period. The long-line grounds were good off Erimosaki in August 

 and off Shikotan Island in September and October, The set nets of Funkawan 

 had good autumn fishing. The Etorofu Island set nets had poor fishingo 



1932o™Big catches were made at Kushiro in the latter part of July, 

 but from August on the fishing was very poor. Medium tuna were very 

 scarce, Urakawa had the best fishing in years, and small tima were 

 remarkably abundant. The long-line fishing was poor, 



II, Observations Concerning Habits 



a. Migrations 



In ascertaining the migrational movements of fishes there is the 

 direct method of tagging an-' then recapturing the fish under considera- 

 tion, and there is the indirect method of hypothesizing these movements 

 from the shifts in the seasons and grounds, Ihe latter is liable to 

 be confused with changes in environmental conditions, but in the case 

 of large tuna, which are difficult to tag, this deductive method must 

 be used. 



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