Diatoms

Diatoms are algae that reflect the biotic condition of streams, lakes and estuaries. Diatoms are important indicator organisms because they are sensitive to natural and human impacts, and monitoring their condition provides information about ecosystem health. Diatoms can live in permanently ice-covered lakes in the Antarctic. Here, a dried microbial mat of blue-green and diatoms is present on the surface of Lake Fryxell.