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, R. KRINGEL, M. SCHIMMELE, G. BAFFICO, P. TEMPORETTI AND M. MAGES

Melborune, Australia

Congreso; Congreso de la Sociedad Internacional de Limnología, SIL 2001; 2001

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> 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.