bo Fisning Seasons, Fishing Groxinds, Size of Fish 



Drift-net Fishery 



The drift-net boats of Urakawa and Muroran make their tlrst catches 

 in the coastal waters of HitaKa in the middle or latter part of June, 

 while the boats based at Kushiro begin their season off Srimosaki in the 

 latter part of Jiine„ In both cases the fishing is done 10 to 30 miles off 

 shore o In the middle of July the whole area from Hitaka to Kushiro enters 

 its peak season „ Some years in August the fishery retreats northward to 

 the region of Etorofu I„ The main season in the waters off Kushiro is 

 from the middle of July to the latter part of October and the grounds are 

 about 20 miles off shore (along the fringes of the third branch of the 

 warm current) and about $0 miles off shore (on the edges of the second 

 branch of the warm current). 



Table 1 shows the first day of fishing, the peak of the season, and 

 the date fishing ends at Kushiro „ We look next at the seasons for the 

 various sizes of fish. In table 2 we have followed Mr. Kinosuke Kimura 

 in taking as the median period the 10-day period which corresponds to the 

 statistical mathematical average and then taking twice the breadth to be 

 the peak season^ Further, the number of largej medium, and small fish taken 

 in each 10-day period on a 10-year average is shown in figure 1„ According 

 to this graph, the 10-day period at which half of the catch of large tuna 

 had been taken was earlier than the mean period, while for the medium and 

 small fish they more or less coincided. In neither case is the distribution 

 of the catch very un symmetrical. Table 3 shows the median period of the 

 fishing season for each size of fish. 



As far as the sizes of tima taken in Hokkaido" are concerned, those 

 from Etorofu Island are the largest, some of them attaining weights of 330 

 to 6^0 pounds, Ihe next largest are the fish taken in the set nets of 

 Funkawan in the autumn, many of these weighing around 330 pounds o At Kushiro, 

 as is clearly shown in tables 2 and 3 and in figure 1, large fish predominate 

 at the beginning of the season, with the average weight commonly over 250 

 poundso Thereafter medium and small tuna appear, and by the middle of 

 August the number of small fish exceeds the number of large oneso In 

 October with the strengthening of the cold currents the small tuna are 

 gradually driven out and the average size of the fish increase So Table U 

 shows the average weights of fish for each month. 



Long-line Fishery 



The first long-line catches are made in August, later than those of the 

 drift-net fishery. The fishing grounds are chiefly in the area from off 

 Eriraosaki to off Shiriyasaki and farther out to sea than the drift-net fishing 

 grounds. The waters east of Srimosaki provide no good fishing except in the 

 autumn when the tuna are returning southvfard. Good fishing is sometimes 

 found to the southeast of Shikotan Island, The peak season is from September 

 to November, and the last catches are made off Shiriyasaki in December, 



