Tendenze dei carichi di nutrienti riversati dal fiume Po nel mare Adriatico

Nutrient discharges of the Po River during the last 50 years are compared to anthropogenic emissions due to the usage of detergents and fertilizers, in order to understand the reasons of the current nutrient imbalance in the Adriatic Sea. River transport of inorganic N increased from the 1970 reaching a maximum in mid ’90, showing strong oscillations in the last decades (54-145 kt N yr-1). The transport of reactive P showed a marked increase until the ’80 (7 kt P yr-1) and a strong decrease in the following decades. This decline was consistent to the usage of the fertilizers in the drainage basin of Po, suggesting that the measures adopted in the past for the mitigation of the eutrophication in the N Adriatic (i.e. P reduction in the detergents and improvement of wastewater treatments) were not the only reasons of the current P-scarcity in this marine region.