Wetland has developed from low and intermediate to high moor over the long time, and this process of this transittion are able to be classified into three; inland marsh, slough marsh, and back marsh.
Hokkaido, including Kushiro region, experienced high sea level between 10000 to 6000 years ago due to the drastic rise in temperature. Majority part of Kushiro wetland was then considered to be located under the sea. About 6000 to 4000 year ago, however, the sea level began to decline, and the area of Kushiro wetland was separated from sea at this time. Salt water remained at the area of Kushiro wetland then had been desolted over a a long time, and accumulation of substrate began to form like wetland as present. Some heritage of this precess, from sea to wetland, can be found, such as the existing of opposum shrimp, which in general exist at sea water, at Toro Lake.
opposum shrimp
Comparison of Kushiro Wetland National Park and Sea level of 6000 years ago
Fundamental Info.
Topic 1
People and Wetland
