Water, Air, and Soil Pollution

, Volume 85, Issue 2, pp 511–516

Natural acidification of lakes and rivers in Japan: The ecosystem of Lake Usoriko (ph 3.4–3.8)

  • Kenichi Satake
  • Akira Oyagi
  • Yasuko Iwao
Part II Natural Versus Anthropogenic Acidification

DOI: 10.1007/BF00476880

Cite this article as:
Satake, K., Oyagi, A. & Iwao, Y. Water Air Soil Pollut (1995) 85: 511. doi:10.1007/BF00476880


Most of the acid lakes and rivers in Japan have been influenced by acid waters of volcanic origin. Acidophilic and acidotolerant organisms are observed in these natural acid lakes and rivers, each of which has its own ecosystem and history. Lake Usoriko (pH 3.4–3.8) is a lake which.has been acidified by strongly acid water containing sulfuric acid and hydrochloric acid. The ecosystem of Lake Usoriko consists of aquatic vascular plants, aquatic bryophytes (Drepanocladus fluitans, etc.), algae, fish (Tribolodon hakonensis), insects, Zooplankton, fungi and bacteria. The paleosediment distributed along Lake Usoriko's northern shore is partly silicified and it contains fossils of a moss (Drepanocladus fluitans) and diatoms such as Pinnularia braunii var. amphicephala which are also distributed in the present lake. 14C dating of the specimens in the paleosediment, shoots of D. fluitans and the wood and cones of Picea glehnii gave values in the range 11500–34000y B.P. This record shows how long Lake Usoriko has been an acid lake.

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Kenichi Satake
    • 1
  • Akira Oyagi
    • 2
  • Yasuko Iwao
    • 3
  1. 1.National Institute for Environmental StudiesIbarakiJapan
  2. 2.Tanabu High SchoolAomoriJapan
  3. 3.Kansai Junior College of Foreign LanguagesOsakaJapan