Land area: 28,788 ha
Designated on July 31, 1987
Kushiroshitsugen Marsh is the largest marshland in Japan and famous for its beauty as well as the fact that it is the first wetland in Japan which was recorded as a Ramsar Convention site. The marsh is a habitat for Japanese cranes. While their number decreased sharply in the past, they have been recovering continuously. This is the result of the rich natural environment in this area and people's efforts to conserve it.
Kushiroshitsugen National Park is composed mainly of Kushiroshitsugen Marsh and other wetlands. It is a very new national park which was designated about twenty years ago.
Kushiroshitsugen Marsh took its present landform about three thousands years ago after its formation period of supposedly about twenty thousands years. A low moor accounts for 80% of the marsh and areas of intermediate and high moors are very small. Therefore, the vegetation in the marsh shows strong characteristics of that of low moors and mainly consists of reeds and sedges. In the eastern part of the marsh, there are three lagoons which show that the land used to be under the sea.
Kushiroshitsugen Marsh has not been reclaimed on a large scale to date because it is too cold to cultivate rice and there are several rivers which often overflow. After World War II, there was a plan to reclaim the wetland and utilize it for agriculture, however, the plan was not implemented and the rich natural environment of Kushiroshitsugen Marsh has been preserved as a national park.
Kushiroshitsugen Marsh has about two hundred varieties of vegetation including some plants with the word "Kushiro" in their names such as Kushiro jacob's ladder (Polemonium caeruleum subsp. laxiflorum var. paludosum), an endangered plant which bears pretty flowers.
One of the main factors that made the world recognize the importance of Kushiroshitsugen Marsh among Japan's wetlands is Japanese cranes that breed it. The marsh is their major breeding ground. They have a special meaning in Japan as Japanese people recognize them as the symbol of the country, and their gracefulness fascinates many bird lovers. However, it was once thought that they became extinct in Japan. In 1924, they were found again here, in Kushiroshitsugen Marsh. The number of cranes observed at that time was only twenty or thirty and careful conservation measures have been taken since then. These paid off and the population has been recovering continuously.
Regarding the water environment, Kushiroshitsugen Marsh is the habitat of many rare Amphibia and insects that can be seen only in this area. However, some species including Japanese huchens have been decreasing in number.
It is being recognized more clearly that careful measures must be taken to conserve this area's natural environment. For this purpose, facilities for environment education such as the Kushiroshitsugen Marsh Wildlife Conservation Center were established, and special sightseeing tours, called eco-tours, to deepen people's understanding of the environment are operated. Also, some projects are being implemented to conserve and restore nature against human-induced changes such as shrinkage of the wetland due to development in the surrounding area, and aridification as the result of the inflow of sediment.