Charophytes are extremely beneficial to lakes, improving water quality and biodiversity. However, their abundance was found to decline in many lakes without clear signs of eutrophication during recent decades.

Charophytes are underwater plants that play a crucial role in the water quality and biodiversity of lakes; they stabilize the lake bed, produce oxygen, promote water clarity, and provide habitat for numerous aquatic organisms. In Europe, their abundance has declined sharply since the late 19th century.