KASAHARA: JAPANESE DISTANT-WATER FISHERIES 



the mothership fishery before World War II, 

 which was conducted in waters very close to the 

 Kamchatka Peninsula. The result was a smash- 

 ing success, and this set a pattern for further 

 development of the mothership salmon fishery 

 on the high seas. The land-based drift-net fish- 

 ery, too, operated in a large area of the high seas; 

 1,500 drift netters fished for salmon, mostly pink 

 salmon heading for Soviet streams. The gov- 

 ernment issued new regulations for the land- 

 based drift-net fishery. 



By 1955, the mothership expanded to 14 moth- 

 erships, including 2 in the Okhotsk Sea, with 344 

 catchers and 58 scouting boats; the land-based 

 drift-net fishery was conducted by 325 larger 

 vessels (over 30 gross tons) licensed by the cen- 

 tral government and more than 1,200 smaller 

 vessels licensed by the prefectural governments. 

 The mothership fishery took 64 million salmon 

 (in number of fish) and the land-based fishery 

 47,000 metric tons (in round weight). Japan 

 had planned to increase the number of mother- 

 ships to 19 in 1956 with a corresponding increase 

 in the number of catcher boats. 



In February 1956, the Soviet Union took uni- 

 lateral action to restrict high seas salmon fishing 

 in the northwest Pacific (west of long 170°E). 

 The two governments entered into negotiations 

 for a fishery treaty, which was concluded on May 

 15 and entered into force a few months later. 

 The diplomatic relations between the two nations 

 were restored later in the year. The new fishery 

 treaty set forth a wide variety of regulations, 

 including large closed areas, closed seasons, 

 catch quotas, restrictions on fishing gear, and 

 arrangements for enforcement (a system of in- 

 spection by the Soviet authorities). Many 

 changes have taken place since then, including 

 the development of a large longline salmon fish- 

 ery on the high seas and a substantial salmon 

 fishery in the Japan Sea, expansion of the reg- 

 ulatory area, changes in the allocation of fishing 

 grounds and catches between different Japanese 

 fisheries, the closure of the entire Okhotsk Sea, 

 and continuous modifications of the domestic 

 regulations to meet the international situation. 

 The pattern of salmon fishing as of 1969 is sum- 

 marized in Figure 3. The number of catchers 

 has been reduced substantially by transferring 



their licenses to the tuna longline fishery and the 

 northern trawl fishery. Due to expansion of the 

 regulatory area and a continuous reduction of 

 the catch quota under the treaty, which was 

 considered necessary by the Soviet Union for 

 conservation, the total take of salmon by Japan 

 (including small amounts of salmon destined 

 for Japanese streams) decreased from 197,000 

 metric tons in 1958 to 141,000 metric tons in 

 1969 (Ministry of Agriculture and Forestry, 

 1971). 



In short, the expansion of the Japanese high 

 seas salmon fisheries came to an end already in 

 the 1950's when regulatory measures under the 

 Japan-Soviet fishery treaty were applied to 

 practically all areas of the northwest Pacific 

 in which salmon were found. Oflfshore fishing 

 must have had adverse efl^ects on the salmon 

 stocks in general, but the exact nature and extent 

 of such efl^ects are not well understood from the 

 data and information exchanged through the 

 Japan-Soviet fisheries commission. 



The eastern boundary of the offshore salmon 

 fishing grounds was established at long 175°W 

 under the North Pacific treaty. In spite of exten- 

 sive research conducted on the offshore distribu- 

 tion of salmon, resulting in a wealth of scientific 

 information, and continuous hard negotiations 

 between the national sections of the North Pacific 

 fisheries commission, this provisional line has 

 remained unchanged to date. Substantial quan- 

 tities of Bristol Bay sockeye salmon have been 

 taken by the Japanese mothership fishery in 

 years of large runs, but none of the three parties 

 has seriously considered the termination of the 

 treaty, which could have been done at any time 

 after 1963 with 1 year's advance notice. Thus, 

 the provisional line drawn in 1952 has proved 

 to be a good political compromise as far as these 

 three countries are concerned. 



CRAB FISHERIES 



Three species of king crab (Paralithodes) and 

 tanner crab (Chionoecetes spp.) have been ex- 

 ploited by the high seas crab fisheries in the 

 northern North Pacific. The most important 

 are the true king crab (P. camtschatica) and 

 the tanner crab. Abundant resources occur in 



239 



