霧多布湿原ナショナルトラスト

Kiritappu Wetland

Kiritappu Wetland is a mire with an area of 3168ha, located in Hamanakacho, a town in eastern Hokkaido.

It is the third largest wetland in Japan. The Kiritappu Wetlands were designated as a site of international importance by the Ramsar convention in 1993.

From northwest to south of the mire along the coastline of Hamanaka Bay, Shinkawa River, Dorokawa River, and Biwasegawa River run through it in parallel, accompanying a series of small narrow ponds including Junsai-numa, Onuma, Naganuma, Konuma, and Korikirinuma.

The topography has been developed through the process after a coastline retreat at the end of the glacial age:a row of sand dunes was built along the new coastline, ponds were created in their hinterland, and the mire was formed.

In 1993, Kiritappu-Shitsugen total area of 2504ha with the core area 2030ha plus Lake Hichirippu and Lake Mochirippu 474ha, was designated as a site of international importance by the Ramsar Convention.

Of the core area, 803ha was designated as a National Natural Monument in 1922, recognized its value for having peat-forming plant communities.