Northward Floating Ship

This is a general term for bottom trawl fishing vessels that have shifted their fishing area from the coastal waters of Japan to the northern seas as a result of Japanese fisheries policy. In 1960, the Japanese government announced the "Guideline for shifting medium-sized powered bottom trawl fishing to the northern seas" in order to preserve the resources of benthic organisms in the coastal waters and to diversify fishing efforts, as the fishing grounds in the coastal waters of Japan had been devastated by overfishing by bottom trawl fishing vessels. Based on this, medium-sized powered bottom trawl fishing vessels that mainly operated off the coasts of Tohoku and Hokkaido were shifted to the northern seas. The fishing area is the area bounded by latitude 48 degrees north, longitude 153 degrees east, and longitude 170 degrees west. The main fishing area is the coastal waters of East and West Kamchatka, and almost all vessels operate in this area, especially during the spawning season of Alaska pollock (December to April). Other target fish species include flatfish such as Greenland flounder and brown flounder (spring to summer), Arctic shrimp, striped shrimp (May to August), Japanese squid (July to September), Pacific cod and Pacific cod along the Aleutian Islands (spring to summer).

When the fishing grounds were first converted, the fishing boats used were generally less than 200 tons, but this was soon increased to 300 tons, and then to 315 tons as a measure to improve the working conditions of the crew, and then in 1965, due to a series of marine accidents caused by low pressure, the tonnage was increased to 350 tons in 1967. Most of the fishing boats turning north have two decks, and the appearance of the fishing boats is equivalent to that of 400 to 500 tons. This is because a large part of them does not count towards the gross tonnage, and their loading capacity is also larger than the nominal.

The fishing areas of north-diverting vessels lie within the exclusive economic zones of other countries, and so fishing is carried out according to agreements between nations.

[Hideo Soeda and Kiyoshi Yoshihara]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

日本の漁業政策によって、日本近海から北洋海域の漁場へ操業区域を転換した底引網漁船を総称していう。日本近海の底引網漁船による乱獲によって漁場が荒廃したため、近海の底生生物の資源量保持と漁獲努力量の分散を図るため、1960年（昭和35）日本政府は「北洋海域への中型機船底引網漁業転換要綱」を発表した。これに基づき、おもに東北および北海道沖合で操業中の中型機船底引網漁船を、北洋海域に操業海域を転換させたものである。操業海域は、北緯48度以北、東経153度以東、西経170度以西に囲まれた海域で、主要漁場は東・西カムチャツカ沿岸海域、とくにスケトウダラの抱卵期（12～4月）には、ほぼ全船がこの海域で操業する。その他の対象魚種としてカラスガレイ、アブラガレイのカレイ類（春～夏季）、ホッコクアカエビ、スジエビ（5～8月）、ドスイカ（7～9月）、アリューシャン列島沿いのメヌケ、マダラ（春～夏季）などがある。

　漁場を転換した当初は、使用漁船は200トン未満が原則であったが、その後すぐに300トンに増トンされ、さらに乗組員の労働環境条件の改善のための措置として315トンに引き上げられ、加えて1965年に低気圧による海難事故が続発したために、1967年には350トンに増トンされた。北転船のほとんどが二層甲板で、漁船の外観は400～500トン級に相当する。これは総トン数に加えられない部分が広いためで、積載能力も公称より大きい。

　北転船の操業水域は他の国の排他的経済水域内にあるため、国家間の取決めによって操業が行われている。

［添田秀男・吉原喜好］

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