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.