Indicator value of freshwater red algae in running waters for water quality assessment
Freshwater red algae (Rhodophyta) occur mainly in running waters. They are generally indicators of good water quality (oligotrophic, oligosaprobic). Many of them are also included on lists of threatened algae. According to the literature, the range of occurrence of red algae at the group level is wide for current velocity, water conductivity and pH. At the genus level, some genera seem to prefer or need hard water and an alkaline environment (Compsopogon, Hildenbrandia, Thorea), whereas others prefer soft water (conductivity < 100 μS m-1). They may also occur in acid water (Audouinella, Batrachospermum, Lemanea, Sirodotia and Tuomeya). With the exception of those living in hard waters, most species also have a rather wide ecological tolerance as measured by common water quality variables. Trophic and saprobic classifications seem to depend rather on geographical conditions than on the real ecological preferences of red algal taxa.
Bibliogr. 22 poz., tab.