Diversity of algae in a thallium and other heavy metals-polluted environment

Abstract

Thallium (Tl) compounds are extremely toxic to living organisms, including algae, but there is a dearth of basic information regarding the mechanisms of action of Tl in the environment and its effects on algae in natural conditions. This study examined algal diversity in an environment highly polluted by Tl. Graniczna Woda stream is contaminated by Tl and other heavy metal compounds (Cd, Pb and Zn). There we found 66 algae taxa representing five phyla, among which euglenophytes prevailed. We found that euglenophytes, including Phacus species, can survive and can show high species diversity in the presence of high Tl concentrations. The fact that these small organisms covered only by a pellicle are able to thrive in such inhospitable habitat, shows a great plasticity of these organisms. It is unclear whether the algae of Graniczna Woda stream have a broad tolerance to harmful conditions or rather represent new varieties/clones that evolved in metal-contaminated waters and are adapted to this environment.