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  • Country: 
  • Site number: 
  • Area: 
    1,318 ha
  • Designation date: 
  • Coordinates: 
    43°27'N 144°06'E
Materials presented on this website, particularly maps and territorial information, are as-is and as-available based on available data and do not imply the expression of any opinion whatsoever on the part of the Secretariat of the Ramsar Convention concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.


Akan-ko. 08/11/05; Hokkaido; 1,318ha; 43°27'N 144°06'E. National Park. A freshwater caldera lake lying between two active volcanoes, Me-akandake and O-akandake, formed by volcanic subsidence. A number of rare aquatic freshwater algae, particularly the well-known Marimo Cladophora aegagropila are observed. The lake is also an important habitat for the largest freshwater fish in Japan, Japanese Huchen Hucho Perryi and Kokanee Oncorhynchus nerka. In addition, 65 species of birds and 24 mammals, for example, Eurasian Brown Bear and Yezo Sika Deer, also depend on the lake ecosystem. The lake is surrounded by mixed forests of conifers and deciduous trees such as Ezo Spruce Picea jezoensis, Sakhalin Fir Abies sachalinensis, and Japanese oaks. Main landuses include hydroelectric power generation, fishery, aquaculture, and boating. At Akan Lakeside Eco-Museum Center and Marimo Exhibition Center, visitors, about 1.56 million per year, learn about the history of the lake and the status of Marimo and fish species. Ramsar site no. 1540. Most recent RIS information: 2005.

Administrative region: 
Hokkaido Prefecture

  • National legal designation: 
    • National Park
  • Last publication date: 


Ramsar Information Sheet (RIS)

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