The acidic waters of the Copahue crater – Agrio River–Lake Caviahue system (Patagonia, Argentina)

F. PEDROZO, W. GELLER, G. BEAMUD, S. WOELFL, M. DIAZ, B. A. WHITTON, M. T. WENZEL,

VERH. INTERNAT. VEREIN LIMNOL.

E. Schweixerbart´sche Verlagsbuchhandlung

Año: 2002 vol. 28 p. 112 - 113

0368-0770

The system is an extremely acidic habitat unique probable in South-America. The source has 80 ºC and high acidity (1.5 Molar). Lake Caviahue (pH= 2.5, acidity 1.5 mMolar) is comparable with sulphur acidic mining lakes. It has a low Fe:Al molar ratio (0.22-0.63) suggesting sulphur controls the pH. The biota is similar to that of eutrophic acidic mining lakes: high population density but low species diversity in a phosphorus-rich (500 µg/L) environment.