The Venice Lagoon is characterized by a high concentration of human activities. Two main cities (Venezia, Chioggia) and a number of towns and villages (400,000 residents) are distributed around its perimeter and on some islands; 14 million tourist presences per year contrast with a resident population of 60,000 in the historical centre. Venice has one of the most important ports in Italy (30 million of tonnes of goods per year and 1 million cruise ship passengers), the third busiest Italian airport and the relics of the core of Italy’s petrochemical and chemical industry (Marghera). Urban development, port activities, tourism related pressures and flows, recreational activities, commercial and traditional fishing, industrial and agricultural pollution encounter each other in the Lagoon and influence its natural dynamics and the resilience of the system. Catchment land use is historically a varying mixture of agricultural and industrial.
Lagoon morphology erosion, geomorphic changes, bio-chemical pollution, eutrophication, sediment and turbidity, biodiversity loss and habitat destruction, trophic web change, use depreciation, groundwater systems – in rough order from most studied top least studied.
Maintaining the ”lagoon status”, between sediment inputs and erosion, and defending from sea storms, implies wide human interventions, which in Venice have continued since the XIV century. The presence of industrial and port activities, together with increased human pressures and intensive agriculture in the drainage basin, in the last century focused on the problem of eutrophication and pollution of water and sediment. Venice and its lagoon was declared “of national interest” by an Italian law in 1973 and a “World Heritage Site” by
UNESCO in 1987. Huge economic resources have been spent by the Italian state for the safeguarding of the lagoon, the cultural heritage and for re-vitalizing the city. Cost–benefit ratio of these interventions is still an issue. Considering sea level rise, the physical defence of the city necessitates a mobile barrier system between the lagoon and the sea: after a 30 yearlong debate, the political decision has finally been taken. Fishing of clams is a important economic activity (counting 60% of the national production), but its actual sustainability is uncertain: over-fishing, ‘fishing down the food-web’, sediment resuspension, damage to benthos and habitat destruction are recurrent problems. Granting access to the port, placed on the inner lagoon part, implies excavation of contaminated sediment from silted channels.
Allowing fruition of some lagoon sites, for tourism and fishery, is necessary for the economic life of the residents, but creates easily non-sustainable conditions for the environment. Considering the sea in front of Venice, multi-regional and multi-national approaches are under consideration for an appropriate and effective management, starting with INTERREG initiatives.