Kushiro Marsh, Natural Monument
Since the discovery of ten red-crowned cranes in Kushiro Marsh in 1924, much has been done to protect both the species and their marshland habitat. In 1935, part of the marsh measuring 2,700 hectares was designated as a Natural Monument. The protected area was expanded to 2,749 ha in 1952 and, in the same year, the Kushiro red-crowned cranes as well as their breeding grounds were recognized as a Special Natural Monument. The protected marshland was expanded again in 1967 to 5,012 ha. In 1980, a section of the marsh was designated as a Ramsar Site, recognizing it as an internationally important wetland. Finally, in 1987, an expansive area covering a total of 28,788 ha became Kushiro Shitsugen National Park.
Functions of Marshlands
Kushiro Marsh is not only valued as a natural monument, but is also recognized for its many practical functions. The main benefits of a marsh are:
Water Retention and Flood Control
Marshland stores water like a sponge, which in turn helps to prevent flooding. Marshland is sometimes referred to as a dam without water because, although the land is full of water, much of it remains out of sight, stored in plants or hidden beneath the ground.
Absorbing Greenhouse Gases
Plants that grow in large marshes absorb substantial amounts of carbon dioxide. Even after the plants die, the carbon dioxide remains stored as the decayed vegetation decomposes and becomes part of the soil.
Purifying Water
A marsh works as a natural filter, absorbing sediments and nutrients such as phosphorus and nitrogen from the waterways that flow through within it.
Stabilizing the Local Climate
A marsh holds a large volume of water and thus temperature changes happen very slowly. Due to this inertia, it functions as a buffer to climate change in the local area.
Preserving Biodiversity
Marshlands provide a diverse natural environment. Sedge-reed bogs, peat moss bogs, lakes, ponds, and rivers provide a habitat for many different plants and animals.
A Recreational Retreat
Marshes allow people to experience the wonders of nature and to escape the stresses of everyday life. Popular outdoor activities in marshlands include camping, canoeing, and observing various flowers and birds.
