- Site number:539
- Area:510 ha
- Designation date:12-12-1991
- Coordinates:42°42'N 141°43'E
Utonai-ko. 12/12/91; Hokkaido; 510 ha; 42°42'N 141°43'E. National Wildlife Protection Area. A freshwater lake in the Bibi River floodplain, surrounded by reed-sedge swamp, swamp forest and stands of wild rice. One of the most important staging and wintering areas for Anatidae (ducks, geese, swans, etc.) in Japan. Human activities are fishing and nature conservation devoted to research and monitoring projects. Ramsar site no. 539. Most recent RIS information: 1992.
- National legal designation:
- special protection area in national wildlife protection area
- Last publication date:01-01-1992