Kushiro Marsh is thebiggest marsh in Japan, and is located near the town of  Kushiro in the east of Hokkaido.  The marsh itself is designated a national natural treasure and is named theKushiro Marsh National Park. It is internationally recognized and is registered in the ‘Ramsar Convention’, which aims toprotect important wetlands.
The Japanese crane (tancho), a ‘special national treasure’, lives in the marsh. It was thought to have vanished in the Meiji period, but was found miraculously in this marsh in the 13th year of the Taisho period and has been protected by humans ever since. In addition to the tancho, the marsh is also home to animals such as the Kita-fox and Yezo-deer, plants such as cranberry and Kushiro-Polemonials, and fishes such as Itoh; in all there are more than 2,000 kinds of flora and fauna here.
Much of the marsh (80%) is low moorland (which is replenished by ground and surface water such as Yoshi), dotted withpot-shaped ponds called yachimanako. The diameter of these ponds is under 1 meter, so they are more like small puddles, but the depth of some of them can be as much as4 meters.
In the past, the marsh was called Yachi and no one paid any attention to it, but now it has become a natural wildlifesanctuary.