[Article] Potential of Underwater Cultural Heritage Studies : Focusing on Takashima Underwater Site

application/pdf水中遺跡、特に沈没船は、当時の様子をそのまま残していることがあり、交易のメカニズムを伝えるタイムカプセルに例えられる。諸外国では一九世紀から水中遺跡を研究対象として捉え、古代から近現代の沈没船の研究が進み、すでに数万件の調査事例がある。一方、これまで日本で確認された水中遺跡は数百件と決して多くない。四方を海で囲まれたわが国において海を介した交易無くして日本の歴史や文化を語ることはできないが、その確固たる証拠が眠る水中遺跡を保護し研究する体制は整っていない。水中遺跡の多くは、滋賀県(琵琶湖)、沖縄県、長崎県の三県に集中しており、中世の交易に関する遺跡はほとんど発見されていない。また、沈没船の発見を念頭に海難記録を調べているが、まだ多くの課題が残される。近年、一三世紀の蒙古襲来に関連した沈没船が長崎県松浦市の鷹島海底遺跡で発見され、わが国でも水中遺跡への注目が急速に集まりつつある。 このように、日本国内での水中遺跡を対象とした研究事例はまだ少ないが、鷹島海底遺跡においては今後の研究の方向性・可能性を見ることが出来る。鷹島海底遺跡では、科学研究費による研究や護岸整備に伴う緊急発掘などにより、すでに四〇年近く調査が行われている。二〇一一年と二〇一四年の調査で船体が発見される前から、アンカー、陶磁器類、武器など多くの遺物が発掘されてきた。船体だけでなく、これらの遺物は、文献史料や絵画資料などと合わせて利用することにより、より正確な歴史事象の理解に貢献することが出来る。水中から引き揚げられた遺物は、保存処理に時間を要するが、現在、研究は着実に進んでいる。これまで鷹島で発見された船体のパーツや遺物などから判断すると、鷹島で沈没した船団のほとんどは、中国南部、揚子江以南に起源を持つ。本稿では、国内での水中遺跡調査の進展を望み、水中遺跡調査の学史、鷹島海底遺跡で行われた研究事例を紹介したい。The underwater archaeological sites are often called the time-capsule of the past maritime trade. The study of underwater remains has its origin in the 19th century and over ten thousands sites have been investigated. However, only a few hundred sites have been investigated in Japan. The island nation with close relationships with the seas throughout history, has no firm management plan for underwater cultural heritage. I have been gathering information of underwater archaeological sites in the country, but the data are highly skewed due to uneven distribution pattern in geographic locations, ages, and types of sites. A large majority of underwater sites are located in three prefectures, Shiga Prefecture (Lake Biwa), Okinawa Prefecture, and Nagasaki Prefecture, and few medieval trade sites have been found. I am also collecting and analyzing the records of marine accident in historical documents, but many challenges still remain. In short, it is too early to discuss the nature and the potential of underwater archaeological sites in Japan. Despite the fact that only a small number of underwater archaeological sites have been studied, we can see the direction and possible future research plan. The Takashima underwater site, where the remains of the lost fleet of Khublai Khan was recently discovered, shows a great potential. The investigation at the site began nearly 40 years ago. Various groups have led the investigation at Takashima; archaeological investigations were funded by scientific research grants and some investigation conducted as rescue excavations. A large number of artifacts - such as anchors, ceramics, weapons, and fragments of ship timbers - has been excavated at the site though these projects. However, these were all single isolated artifacts scattered all over the seafloor. The breakthrough came in 2011 and 2014, with the discoveries of nearly intact hull of two Chinese vessels. The two hull remains, together with the scattered artifacts, can contribute to a more accurate understanding of historical events by using them in conjunction with historical documents. Relics raised from the sea requires a long period, often several years to conserve them properly. Judging from the currently available data, the majority of the vessels sank in Takashima were constructed in southern China and south of Yangtze River. Through this paper, I hope to contribute to the progress of the study of underwater cultural heritage sites in Japan.departmental bulletin pape