OBSERVATIONS OF JAPANESE PELAGIC FUR SEAL RESEARCH 



The provisions under "Article II, Para- 

 graph 5, of the Interim Convention on Con- 

 servation of North Pacific Fur Seals" en- 

 courage the exchange of scientific personnel 

 between member Parties subject to mutual 

 consent of the Parties directly concerned. 

 Under this provision, a U.S. biologist, Hiroshi 

 Kajimura, went to Japan in April and May 1967, 

 to observe Japanese pelagic sealing methods. 

 Trial methods seen were: (1) Attempted se- 

 lection of animals by size and sex; (2) use 

 of .30 caliber rifles instead of shotguns to 

 collect seals; (3) attempted improvement of 

 information on loss among seals shot at sea; 

 and (4) changes in preliminary handling of 

 skins aboard the vessel and on shore before 

 the skins are shipped to the processor. 



The headquarters of biologists studying fur 

 seals are at the Tokai Regional Fisheries 

 Research Laboratory, Tokyo. (It was moved 

 to Shimizu in 1967.) Pelagic fur seal research 

 data are analyzed at a field station in Ozuchi 

 (Akahama), a small fishing village in Iwate 

 Prefecture (fig. 19). 



VESSELS 



NORTH PACIFIC 



ocein 



OZUCH 

 KAMftlSHI 



Figure 19.— Area of operation and fishing villages 

 visited by the Tenyu Maru off northern Japan, 

 14 April to 10 May 1967. 



deckhands. A field investigator was also aboard 

 the vessel to collect and record biological 

 data. 



Two harpoon vessels, the No. 3 Hachiman 

 Maru, 30 and No. 5 Tenyu Maru , 31 (fig. 20), 

 were chartered by the Japanese Government 

 in 1967 for pelagic fur seal research from 

 8 January to 31 May 1967. Austin and Wilke 

 (1950), Tanonaka(1958), 32 and Kajimura (1967) 

 have described these vessels, or "tsukimbo- 

 sen." 



The two ships were nearly identical except 

 that the Hachiman Maru had a pilothouse with 

 wheel amidships and a wooden tiller attached 

 directly to the rudder; the Tenyu Maru had a 

 pilothouse aft but only a wooden tiller (fig. 21). 

 These wooden tillers onboth vessels were used 

 for steering while sealing. Vessels respond to 

 such a tiller more quickly than to a tiller 

 moved by a conventional steering wheel located 

 amidships--a distinct advantage whenfollowing 

 an animal that changes direction rapidly. 



The 12-man crew on each vessel included 

 a captain (who is usually the chief hunter), 

 engineer, boatswain, radio operator, cook, 

 and seven others who are both fishermen and 



No. 3 Hachiman Maru ; length 18.3 m. (60.1 ft.), 

 34.14 metric tons, 180 hp., cruising speed 15 km. per 

 hour (8 knots). 



31 No. 5 Tenyu Maru ; length 18.1 m. (59.3 ft.), 29.95 

 metric tons, 120 hp., cruising speed 15 km. per hour 

 (8 knots). 



32 George K. Tanonaka. 1958. A report on Japanese 

 Pelagic Sealing Research Methods and Techniques in 

 1958. BCF Marine Mammal Biological Laboratory, Seattle, 

 Wash., 53 pp. [Processed.] 



AREA OF OPERATIONS 



Japan carried out fur seal research off 

 Iwate and Aomori Prefectures, north of Ozuchi 

 between lat. 39°20' N. and 40°50' N. and 

 offshore to long. 143°50' £. (fig. 19) from 

 15 April to 9 May. 



OBSERVATIONS 



The range of these relatively small harpoon 

 vessels is limited to about 185 km, (100 

 nautical miles) per day, Seala were usually 

 hunted 19 to 93 km. (10-50 nautical miles) 

 offshore. The vessels left port each morning 

 between 1:00 a.m. and 4:00 a.m., depending 

 on the area to be covered, and entered a 

 harbor each night. They drifted offshore only 

 when the sea was calm. 



To watch for seals, the hunters and lookouts 

 stood on the harpooning and shooting platform 

 supported by the bowsprit. The captains guided 

 their vessels into water with surface tempera- 

 tures of 7° to 10° C.i because it is here that 

 fur seals are usually most abundant off the 

 northern coast of Honshu Island during April 

 and May. Water temperatures were read 

 directly from a dial-type gauge mounted in 

 the pilothouse. 



The vessel approached a seal at full speed 

 if the animal was moving away from the 

 vessel. A resting or sleeping seal was ap- 

 proached slowly and quietly (fig. 22), Two 

 hunters stationed on the shooting platform 

 used either single- or double-barrelled 12* 



47 



