The authorities are on the alert and are looking in the laboratory for answers to the cause of the fish death that is taking place in various areas of the Turin area. In particular in Chivasso, in the Parco dei Sabbioni, on the left bank of the Po, the answer is between anoxia or toxic substances. The latter hypothesis, however, is questioned by the fact that, unlike the River Dora Riparia and the Po at Meisino, no ducks or dead seagulls have been found. Therefore the reasons would fall on the oxygen deficit, probably due to the effects of the great drought suffered by the Po in the summer months, and a consequence of how the river ecosystem has been compromised. Thus thousands of fish massed in the small channel, the Rio Orchetto, probably to take refuge from the winter. But due to the low flow rate of the river, their concentration in a single point has created an oxygen deficit which, in addition to stunning the fish, could condemn them to death.