Lake Akan

Lake Akan (阿寒湖, Akan-ko) is a lake in Kushiro, Hokkaidō, Japan. It is located in Akan National Park and is a Ramsar Site.^[2][3]

History

Volcanic activity formed the lake some 6,000 years ago, when a lava dam was formed. The lake used to have a clarity of 8–9 meters in the 1930s. Pollution from local hotspring resorts has decreased the transparency to 3–4 meters.^[4]

Flora and fauna

The lake is famous for the marimo (Aegagropila linnaei), aggregations of algae that form into spherical shapes 2–30 cm in diameter. Other flora of the lake include the following:^[4]

• Phragmites communis
• Nuphar sp.
• Potamogeton crispus
• Hydrilla verticillata
• Myriophyllum verticillatum
• Vallisneria gigantea
• Melosira italica
• Asterionella formosa
• Synedra

Kokanee salmon (Oncorhynchus nerka) are native to Lake Akan. Other fauna of the lake include the following:^[4]

• Zooplankton:
  • Daphnia longiremis
  • Bosmina coregoni
  • Eurytemora affinis
• Bottom:
  • Chironomus plumosus
  • Tubificidae
• Fish:
  • Common carp
  • Crucian carp
  • Pond smelt
  • Big-scaled redfin

Climate

Gallery

• 
  Akan Caldera
  Lake Akan (center)
  Mount Meakan (bottom left)
  Mount Oakan (center right)
• 
  Lake Akan and Mount Oakan
• A few scenes in 2021

See also

• List of Special Places of Scenic Beauty, Special Historic Sites and Special Natural Monuments
• Ramsar sites in Japan

References

1. "Akan-ko". Ramsar Sites Information Service. Retrieved 25 April 2018.
2. "Data Summary: Akan-ko (Lake Akan)". World Lakes Database. International Lake Environment Committee. Archived from the original on 2012-04-20. Retrieved 2009-05-18.
3. "Ramsar Sites in Japan - Akan-ko" (PDF). Ministry of the Environment. Retrieved 24 March 2011.
4. "AKAN-KO (LAKE AKAN)". World Lakes Database. International Lake Environment Committee. Archived from the original on 2012-03-05. Retrieved 2009-05-18.
5. 観測史上1～10位の値（年間を通じての値）. JMA. Retrieved March 3, 2022.
6. 気象庁 / 平年値（年・月ごとの値）. JMA. Retrieved March 3, 2022.