[en] Algae are an ideal marine species to study responses to different environmental factors free complication inherent in research with more complex higher plants. One of the advantages of environmental study using algae is the possibility to achieve and observe many generations during relative short time period. Algae materials have been used as ecological and environmental indicators to monitor and control in many fields of study such as freshwater and marine ecosystems, soil fertility, industrial applications, etc. It also has been shown that algae assemblages could be used as indicators of clean or polluted water. Previous studies proved high sensitivity of the most algae towards changing of environmental conditions, especially as consequences of water pollution. Algae respond rapidly and predictably to a wide range of pollutants and potentially use full early warning signals of deteriorating conditions and possible causes. Because of their nutritional needs and their position at the base of aquatic food web, algae indicators provide relativity unique information concerning ecosystem conditions compared with commonly used animal indicators. In most cases ecologically relevant signals of ecosystem changes are being provided that can be used to distinguish acceptable from unacceptable environmental conditions. Algae indicators are also a cost-effective monitoring tool as well. (Author)