Qualità delle acque dei fiumi marchigiani: situazione del fiume Metauro

The quality of the waters in the River Metauro was studied chemically, chemico-physically, bacteriologically, and biologically (biological mapping after a study of the benthic macroinvertebrate communities). The biological monitoring in the middle-coastward stretch evidenced a situation worse than that to be deduced from chemical analysìs, This discrepancy may be attributed to the presence of numerous wastewater treatment plants, which determine a significant decrease in the organic contént of the discharge before its being poured into the watercourse. The classical chemical parameters are therefore acceptable, while the macroinvertebrate communities are at the same time seen to be suffering. Furthermore, it should not be excluded that there is a discontinuity in the proper working of these plants, together with the occasional discharge of toxic waste that does not appear in the chemical sampling, but that nonetheless leaves its trace in the organisms living in the watercourse. For a correct reading of the state of pollution of the running waters. the need is thus felt to set up an integrative study, not just one confined to the classical chemical and bacteriological parameters but that includes biological indicators as well.