Rough stonewort
Chara aspera
The rough stonewort is a delicate, annual to perennial algae that typically grows between 5 and 40 centimeters in height. It is characterized by its rough surface, caused by small, spreading spines on the main axes. The species is dioecious and often develops conspicuous, white, star-shaped or spherical bulbils on its rhizoids for vegetative reproduction. It prefers calcareous, clean standing waters and can also be found in brackish water environments.
Details
Oxygen production
Produces oxygen during photosynthesis, which is released directly into the water.
Habitat function
Forms dense underwater meadows that serve as cover for zooplankton and nurseries for fish.
Nutrient uptake
Highly efficient nutrient uptake; promotes phosphorus sequestration through biogenic decalcification.
Food source for
Important food source for waterfowl such as the Red-crested Pochard (Netta rufina).
Human use
No direct economic use, but of great importance for water quality management.
Ecology
Ecological role
Pioneer species in newly formed water bodies; contributes to sediment stabilization and water clarity.
Natural predators
Waterfowl, herbivorous fish, and invertebrates.
Competitor species
Higher aquatic plants (under eutrophic conditions), filamentous green algae.
Ecosystem service
Sequestration of phosphate through calcium precipitation, oxygen production, habitat for juvenile fish.
Threats
Eutrophication due to nutrient input, mechanical disturbances from recreation, water turbidity.
Scientific profile
Profile
Reproduction
Sexual via oospores (dioecious: male antheridia and female oogonia on separate individuals) and vegetative via rhizoid bulbils.
Protection & threats
Main threats
Eutrophication (nutrient input), mechanical destruction through recreational use (anchoring, swimming), water turbidity, and herbicides.