Effect of debris cover on species composition of living organisms in supraglacial lakes on a Himalayan glacier

Supraglacial lakes on a Himalayan debris-covered glacier (Khumbu Glacier in east Nepal) were investigated to identify the organisms living in them. Two kinds of insects, a copepod, a branchiopod, and nine kinds of algae were observed in the lakes. The kinds of organisms identify three types of lakes. Type A: lakes with animals and algae; Type B: lakes with animals only; Type C: lakes without living organisms. Each type of lake had distinctly different water characteristics. Suspended sediment concentration of water in Type A lakes was significantly lower than that in Type B and Type C lakes. Electrical conductivity and surface temperature of lake water was highest in Type A lakes, followed by Type B and Type C lakes. Our results suggest that the species composition in supraglacial lakes is determined by water characteristics and the life span of the lake, which may be due to debris conditions around the lake.