Assessment of the quality of waters of the Frigido river Tuscany by means of the index IBE Extended Biotic Index Valutazione della qualita delle acque del fiume Frigido Toscana mediante lindice IBE Indice Biotico Esteso
Banchetti, R.; Ceccopieri, N.; Bombardieri, G.
Atti della Societa Toscana di Scienze Naturali Residente in Pisa. Memorie Serie B 111: 55-64
ISSN/ISBN: 0365-7450 Accession: 037889973
During spring-summer 2000, a monitoring campaign with Extended Biotic Index (I.B.E.) was carried out on nine stations of the Frigido river. The results of I.B.E. show a biological fragility - connected with the oligotrophy of the waters - in the spring area, a good quality in the tributaries, a slight deterioration (I-II and II Class of Quality) in the middle reach of the river and a sensible worse situation (III and IV C.Q.) in the flat reach. The comparison with the campaigns carried out between 1980-2000 shows that the reclamation of the chemical and hygienical quality of the waters (got principally by the interruption of the waste waters coming from marble sawing) is a necessary but not sufficient condition to recover the biological quality and the colonies of macro-invertebrates. As the negative effects of the waste waters continued (even years after their interruption) in 1997 the bed of the Frigido river was reclaimed, removing about ten thousand tons of marble dust. The monitoring campaign in 2000 put in evidence a remarkable reclamation of the biological quality, so confirming also the peculiar ways of environmental impact of sawing waste waters and marble dust, explained not only by the deterioration of waters but also by the destruction of the varieties of micro-habitats in the substratum of the river. From the elements of the environmental diagnosis drawn from the survey, suggestions for environmental reclamation and restoration have been developed.