[Use of algal indicators (diatoms) for monitoring rivers].

Diatoms are widely used for monitoring rivers in many European countries, where standard methods are applied. The study of specific composition of epilithic diatoms can give useful information on biological quality of rivers. In Italy a method (EPI-D eutrophication pollution index with diatoms) has been developed for Appenine watercourses, based on sensibility of diatoms towards organic pollution, mineralization of water and chloride. Sampling protocols for epilithic diatoms and determination of EPI-D are described, together with application perspectives in Italy.