The Valli di Comacchio (44.55-44.65°N, 12.10-12.25°E) are a large (115 km2) complex of shallow-water (with depth ranging from 0.5-1.5 m) brackish lagoons located in the southernmost part of the Po River deltaic area (Figure 1). The Valli are, nowadays, constituted by three main basins, i.e. Valle Magnavacca, Valle Fossa di Porto and Valle Campo. This semi-enclosed lagoonal complex is almost completely surrounded by earthen dikes, and separated by the sea by the highly anthropogenically impacted, 2.5 km-wide Spina spit.The Valli are connected with the Adriatic Sea by three marine channels, Portocanale, Logonovo and Gobbino, but since the latter is impounded, major water exchange with the sea occurs only through the firsts two channels. The former receives also nutrient-enriched continental water from Valle Fattibello.   Valli di Comacchio Information Document