What are the effects of acid sulfate soils?
With increased acidity (lower pH) in acid sulfate soils, iron and aluminium may become soluble in toxic quantities, with their precipitates affecting water quality and coating streambanks and benthic (sediment-dwelling) organisms. Deoxygenated water may also be related to acid sulfate soil oxidation, together with the decomposition of pasture plants killed by waterlogging. Secondary oxidation of the Fe2+ produced by acid sulfate soil oxidation consumes oxygen and lowers the level of dissolved oxygen in streams. Silica and other compounds dissolved from acid sulfate soils by acid may also cause algal blooms. Fresh water is particularly affected by acid due to its lack of buffering ions. Substances produced by acid sulfate soil also tend to be poorly diluted because of the generally low flows of Australian rivers. Low pH and aluminium toxicity can cause massive kills of aquatic life, including large numbers of fish, despite the ability of mobile organisms to often avoid poor quality wate
