The Sacca di Goro lagoon and an arm of the Po River

The Po di Volano canal–Sacca di Goro lagoon is a small hydrographic system partially located in the southern part of the Po River Delta. The total surface area is 830 km2 for the watershed and 26 km2 for the lagoon, respectively. The watershed is exploited for agriculture, whilst the coastal lagoon is one of the most important European sites for clam (Tapes philippinarum) farming. The lagoon and small inland zones are also included in the Po River Delta Regional Park. Since the mid 1980s, in the Sacca di Goro lagoon abnormal macroalgal blooms occurred, mainly due to the proliferation of the green seaweed Ulva rigida. The enormous macroalgal biomass production was often followed by summer anoxia and dystrophic crises. In this paper, a review of the main studies concerning altered nutrient cycling and water and sediment pollution is presented. Special attention is paid to the discussion of the different aspects of the watershed–coastal lagoon interactions: main features of the watershed and its evolution, anthropogenic pressures, river runoff influence, nutrient and other contaminant cycles, shellfish farming, and macroalgal blooms. Finally, a brief presentation of possible scenarios is given in an ecological economics perspective.