Limnology of the Rio Agrio and Lake Caviahue

GELLER, W.; BAFFICO, G.; DIAZ, M.; FRIESE, K.; KOSCHORRECK, M.; KRINGEL, R.; PEDROZO, F.; SCHIMMELE, M.; WENDT-POTTHOFF, K.; WOELFL, S.

Caviahue, Argentina

Workshop; International Workshop Geogenically Acidic Water Systems: Volcanic Waters, Mining Lakes and Rivers; 2004

CRUB - UNComahue

Copahue Volcano in Argentina has a crater lake near the summit at 2.700 m a.s.l. Río Agrio is an acidic river emerging from a geothermic source below the crater lake at the flank of Copahue volcano. The 13-km-long Upper Rio Agrio flows into a glacial finger-lake, Lake Caviahue (1.620 m a.s.l.), the outflow of which is the Lower Rio Agrio. The system of river stretches and lakes shows an acidity gradient from pH 0 to 7 (PEDROZO et al. 2001). The nutrient loads, trophic state and extreme chemistry along this gradient of acidity were studied with an additional focus on sediments, microbiology, zooplankton and planktonic and epilithic algae (see specific abstracts in the following sections of this volume).