Plankton of two Araucanian Lakes of differing Trophic status (Argentina)

DIAZ, M; PEDROZO, F; TEMPORETTI, P

HYDROBIOLOGIA

Kluwer Academic Press

Año: 1998 vol. 369 p. 45 - 57

0018-8158

The Araucanian lake district in southern South America encompasses many great of glacial origin, as well as a large number of smaller lakes. In this study, we present data on two waterbodies, one large (Nahuel Huapi), and one shallow (Verde). The phytoplankton community structure and dynamics or either lake were monitored for a year, in relation to the physical and chemical fluctuation, as well as the morphometry of the respective basins. In the large lake, the phytoplankton biomass was strongly dominated by diatoms (Aulacoseira granulata, Rhizosolenia eriensis and Cyclotella stelligera) and by dinoflagellates (gymnodinium and Peridinium spp.). In the small lake, maximum, and Rhodomonas lacustris, Chrysochromulina parva and Navicula spp. during autumm. The maximum biomass value was 634 mg m-3 in lake Nahuel Huapi in sprimg and 7800 mg m-3 in Lake Verde in summer. According to their phytoplankton and physical and chemical features, Lakes Nahuel Huapi and Verde are readily classifiable, as ultra-oligotrophic and mesotrophic, respectively.