Relationship between light availability, chlorophyll a and total suspended solids in a Southern Andes glacial lake

MODENUTTI, BE; PÉREZ, GL; BALSEIRO, EG; QUEIMALIÑOS, CP

VERH. INTERNAT. VEREIN LIMNOL.

E. Schweizerbart'sche Verlagsbuchhandlung

Lugar: Sttutgart; Año: 2000 vol. 27 p. 2648 - 2651

0368-0770

The light climate of oligotrophic lakes is normally characterised by high transparency, leading to deep euphotic zones. However, inputs of allochthonous particles to oligotrophic lakes can affect vertical light attenuation, and, consequently, influence phytoplankton communities. Glacial lakes frequently receive inputs of finely ground rock particles of glacial origin; thus, upper glacial lakes often have a grey or whitish appearance. In contrast, the lower lakes in a series of glacial lakes can be blue because all particles have settled out of the water column.In this study, we will analyse temperature, suspended solids and chlorophyll a (Chl a) and light distributions along the lake gradient in a summer sampling.In the deep Mascardi Lake, the euphotic zone is included within the mixed layer in the Tronador arm, while in the Catedral arm the euphotic zone extends beyond the thermocline. The pronounced spatial differences in Kd, Chl a, and TSS in both arms illustrates how light attenuation by mineral particles can limit phytoplankton distribution in deep lakes.