Limnological Fundamentals of Acid Mining Lakes

Acidic mining lakes are clearly different from softwater lakes that have been acidified by aerial deposition, but despite their unusual ecosystems, they have attracted little scientific interest in the past. Their only natural counterparts appear to be acid crater lakes which, similarly, have been poorly studied. With acid mining lakes, the acids (mainly sulphuric acid), result from drastic man-made changes in the subsoil redox system, i.e., by aeration and the weathering of sulfuric minerals. Any discussion of the chemical characteristics of different types of mining lakes, therefore, is not based on the chemical composition of the lake water alone. Equally important is the hydrogeological environment of the lake, in that it functions as a source of, or sink for, acids, iron and dissolved metals.