REKIHAKU

No.136 A Witness to History

Exploring the lost world of inland seas through historical materials
(Kazuki Takahashi)

The unique landscape of scattered lagoons of varying sizes and the rivers flowing down from the mountains that spill into these lagoons is important when examining the regional characteristics of the Japan Sea coastline with its well-developed chain of sand dunes. However, traces of the historical existence of inland seas formed by rivers, bays and lagoons penetrating far into the interior have been found not only along the Japan Sea coast, but also along Japan's Pacific coast down to the coast on the East China Sea. This discovery is prompting a change in the conventional way in which historical materials have been interpreted. Some examples are to be found in maps dating from the first part of the Edo period. Maps from the Shoho era in the 17th century show Kasumi-ga-Ura and Tsubaki-no-Umi in Kanto, Urato Bay in Tosa Province, and the Manose River basin on the Satsuma peninsula. These "inland seas" provided transportation routes for boats, thus serving as an interface between the ocean and the interior. At the same time, they provided places for the inhabitants of coastal villages to set nets and to hunt birds. They also supplied a source of water for irrigating nearby agricultural land.

One important word when looking back at the history of the relationship between man and these lagoons through to the present day is "umi," the Japanese word for "sea."

Fig. 1: Shoho 17th Century Map of Japan; 240.0 cm x 228.0 cm (Museum collection)	Fig. 2: World of inland seas in Kanto seen in the Shoho Map of Japan The no longer extant Tsubaki-no-Umi can be seen in the eastern part of Shimousa
Fig. 3: Western Japan Sea coast from the Shoho Map of Japan

From ancient times lagoons were described by the term "mizu-umi," as seen in the reference in the Manyo'shu to the "Fuse-no-Mizu-umi" denoting the Junicho Lagoon in Toyama Prefecture. In the section on famous "umi" sites in the "Yakumo-no-Misho," an anthology on poems by Emperor Juntoku who was exiled to Sado in the early part of the Kamakura period, there is a list of "mizu-umi" denoting lagoons alongside the names of present-day oceans. This occurred not only in the world of poetry, as documents and records from the Kamakura period onward, which saw a significant increase in written materials directly concerned with regional society, describe lagoons as "mizu-umi," while present-day oceans are called "shio-umi" and "oo-umi." That is to say, to people who lived in the ancient and medieval periods both oceans and lagoons were "umi" and had a different connotation from the "umi" that is part of the current Japanese lexicon.

Fig. 4: 1792 drawing of Kisa Lagoon (Museum collection)

It appears that a change appeared in the meaning of the word "umi" during the Edo period. It is interesting to note that the use of "umi" to describe lagoons became rare. Instead, use of proper nouns such as "AAA-gata/kata" (Lagoon AAA) and "BBB-ko" (Lake BBB), as is the practice today, became common in documents from the Early Modern period onward. This indicates a major shift in social recognition of lagoons as natural features and the people's associations with lagoons. As such, it shows that people began to regard a lagoon, which up until then had been used for a number of purposes, as something that could be developed. As well as a reduction in surface area caused by deposits of sand and soil carried by rivers flowing into lagoons, there are examples similar to the Kisa Lagoon in Akita Prefecture where an earthquake caused a major uplift of the ground. However, from the standpoint of the disappearance of lagoons as a result of man-made causes, the impact of reclamation projects which have continued through to the present cannot be ignored.

Fig. 5: September 20, 1563 diary entry of travels to the northern districts (Museum collection) A priest from Daigo-ji temple frequently paid boat fares in the area around Kanbara-no-Tsu, Echigo Province (present-day environs of Niigata City)	Fig. 6: Gazing up at Hakusan Mountain from Shibayama Lagoon (historical records of daily life during the Meiji Period) (Museum collection)

Land reclamation carried out from the middle of the Edo period caused a number of lagoons to disappear altogether and greatly reduced the surface area of others. A good example of this is the current forms of the Kiba Lagoon, Imae Lagoon and Shibayama Lagoon, once referred to as the three Kaga Lakes. Shibayama Lagoon, which is situated near an area well known for its hot springs, retained its size until the Meiji period. Until then, boats plied its waters below the majestic backdrop of Hakusan Mountain to the southeast. Today, however, more than two-thirds of the lagoon has been replaced by land. There were instances where following reclamation arable land on the inner and outer sides of the shores of former lagoons was sectioned off in different directions, recalling the outlines of the lagoons of yesteryear. But even this has been made difficult by more recent projects that have seen the rapid development of farmland. Consequently, there are also many places where the times when lagoons existed have been erased from memory. Apart from the perspective of the history of the development of agricultural fields that has continued since the Early Modern period, the existence of "lost inland seas" and their various social functions gleaned from fragmentary materials present a clear picture of the historical features and the futures of lagoons that remain today, or perhaps just as importantly, lagoons that have been allowed to remain.

Fig. 7: Map of the three provinces of Kaga, Noto and Echigo printed in 1826. 83.0 cm x 79.0 cm (Museum collection) The map shows the three Kaga Lakes, Kahoku Lagoon and Ouchi Lagoon

(Medieval Japanese History, Research Department)