Commentary on themes by historical period

i. Surveys of the Senkaku Islands and use of the fishing grounds in the waters around them

　The waters around the Senkaku Islands had been used as fishing grounds both during pre- and post-WWII periods. At the beginning of the 1950s, the Ryukyu Fisheries Research Institute conducted fishing grounds surveys on migratory fish and surveys on sea conditions, among others, while fishermen from Kyushu began to engage in fishing operations for skipjack and marlin, as well as a trawl-net fishery. Results of surveys on fishing grounds and catch levels have been reported by the Kagoshima Prefecture Fisheries Research Institute and the Fukuoka branch of the Fisheries AgencyNo.60.

　In 1953, as the designation of the Syngman Rhee Line meant that fishermen from mainland Japan were excluded from the mackerel fishing grounds around Jeju Island, the continental shelf of the East China Sea around the Senkaku Islands was viewed as potential new fishing grounds for mackerel. To that end, in 1954 and 1959, a joint survey was conducted there by the Nagasaki Prefectural Fisheries Research Institute and the Ryukyu Fisheries Research Institute.

　Even though the U.S. military stationed in Japan continued to use the islands for bombing exercises, the waters around the Senkaku Islands were used by fishermen as good fishing grounds during the postwar period of recovery for the fishing industry. Surveys were conducted by research institutesNo.61No.62.

　 In a document reporting on the production of corals in the context of licensed fisheries in 1967, we found descriptions that include the offshore areas of each of the Senkaku Islands in one of the fishing grounds for coralsNo.63.

ii. Postwar academic surveys

　Academic surveys of the Senkaku Islands conducted after WWII started with a survey by Tetsuo TAKARA in 1950. Based on his experiences during this time, he contributed an article introducing the natural environment of the Senkaku Islands in a newspaper for childrenNo.64. Thereafter, TAKARA formed survey teams in 1952, 1953, 1963, and 1968 to conduct academic surveys of the Senkaku Islands. Many local researchers, particularly from the University of the Ryukyus, participated in these surveys.

　After that, the University of the Ryukyus conducted another survey in 1971. For this survey, a team comprising 15 experts, including professors from the University of the Ryukyus, was formed. The team carried out surveys of animals, plants, geology, water quality, and marine observations at the Senkaku Islands, as well as a comprehensive survey of the fishing grounds. One trait of this 1971 survey was that it was a joint project between the University of the Ryukyus and the Government of the Ryukyu Islands, and featured, for example, the use of the Tonan Maru, a research vessel owned by the Ryukyu Fisheries Research Institute ^(*1) of the Agriculture and Forestry Department of the Government of the Ryukyu IslandsNo.65.