Among the microorganisms, there are also some that carry out photosynthesis. These microalgae and phototrophic bacteria can be easily recognised by their pigments and are found in almost all kinds of waters (e.g.: lake, sea, river). Terrestrial algae that live on surfaces such as flowers or rocks and even in Alpine regions are less well-known. Depending on the species and living conditions, you will find micro-algae in different colors from green to yellow to red.