Effects of aluminium in acidifield aquatic ecosystems

In the acidic aquatic environment, pH, aluminium and calcium are still the three most importent factors to explain losses of biota. The inorganic (labile) monomeric species of aluminium acts as a toxic agent on gill-breathing animals such as fish and invertebrates, by causing loss of plasma and haemolymph ions leading to osmorereulatory failure. A series of different effects on all levels of organization within an organism are described, as well as important population resposes. In contrast of the situation for invertebrates and fish, the aquatic macrophytes seems to tolerate high concentrations of aluminium. The macrophytes appear thus to be much more sensitive for other chemical factors which changes during acidification, especially the shift from bicarbonate-towards direct CO2-uptake as primary source for carbon.United Nations, Economic Commission for Europe, UN-EC