The favorable water temperatures throughout a number of 

 years were from 20 to 21 degrees^ and about $0 to 80 percent 

 of the total catch was taken at these water ten5)eratureSo 

 The next most favorable temperatures v.-ere in the order of 

 22°, 19°, and 23°, In terms of salinities, the greatest 

 catches were centered aroimd salinities of 3Uo8 0/00„ As 

 the table shows, surface water temperatures of 21° appear in 

 the early and middle part of June and coincide with the 

 favorable water temperature for skipjack in the same period. 

 The best fishing grounds, just as in the case of skipjack, 

 are found along current boundaries,, Almost all of the catch 

 is composed of medium sized (25 to U5 pounds) and small 

 (under 25 pounds) fish. 



(b) Oceanographi c conditions and offshore fishing grounds 



The following remarks are based on the results obtained 

 in the course of two cruises in the summer albacore fishery 

 from May 10 to September 2, 19 37, by the Fuji Maru of the 

 Shizuoka Prefecture Fisheries Experiment Stationo This was 

 the first vessel in Japan to attempt summer albacore fishing 

 in the offshore waters. In 1938, with the support of the 

 Ministry of Agriculture and Forestry, the fisheries experiment 

 stations of Aomori, Iwate, Miyagi, Fukushima, Chiba, Shizuoka, 

 Mie, Wakayama, Aichi, and Kanagawa prefectures surveyed the 

 summer albacore longline fishery in the area between 170°Eo 

 longitude and 160° W, longitude, 10° N, latitude to :^° No 

 latitude » Leaving the results obtained by this Station for 

 future publication, the following is based on the surveys 

 carried out by the Shizuoka Prefecture Fisheries Experiment 

 Station „ 



Area surveyed 



First cruise — 160° to 180° E, 

 30° to 31;° No 



Second cruise -- 165° E, to 177„5° W. 

 29° to iil° No 



Survey period 



First cruise ■ — May 10 to June 25o 



Second cruise — June 2k to September 2o 



Fishing gear and bait 



Longlines • — 120 baskets 

 Poles — 30 



Trolling lines and hand lines 



Salted sardines, frozen squid, frozen mackerel, and 

 live sardines. 



