Publications - Occasional Papers

Ecological Processes in a Cold Desert Ecosystem: The Abundance and Species Distribution of Algal Mats in Glacial Meltwater Streams in Taylor Valley, Antarctica.

INSTAAR Occasional Paper 51

1997, 108 pp. (cost: $5)

The McMurdo Dry Valleys, located in South Victoria Land, are the largest of the polar desert oases found along the coast of Antarctica. Glacial meltwater streams are an important aquatic habitat in the McMurdo Dry Valleys.

This report presents results on the abundance and species distribution of algal mats at 16 stream sites in Taylor Valley.

Results indicate that species of filamentous cyanobacteria are the most abundant algae in the dry valley streams. Algal mats were classified on the basis of on apparent color into four mat types. "Black-colored algae" were found in the wetted zone adjacent to the streambed and were primarily composed of Nostoc. "Green-colored algae" were found attached to the surface/undersurface of rocks in the main stream channel and were mainly composed of Prasiola. "Orange-colored" and "red-colored algae" occurred in the streambed regions with the greatest flow and had a greater diversity of species. The abundance of algal mats is controlled by sediment transport and the characteristics of the streambed. Algal mats were more abundant in streams where the streambed is composed of a stone pavement. In streams with abundant algal mats, the nutrient concentrations are lower than in streams with sparse algal mats.

PDF (2 MB) | Corrected Table 32 (1 MB)