Natural recovery and policy interventions of coastal wetlands: Venice Lagoon (Northern Adriatic Sea, Italy) as a case study.

The goals of conservation and sustainable use of environmental ecosystems have increased the need for detailed knowledge of ecological evolution andr esponses to both anthropogenic pressures and recovery measures.The present study shows the effects of natural processes and planned intervention in terms of reducing nutrient inputs in a highly exploited coastal lagoon, describing itsevolution over a16-year period from the late1980s(when eutrophication was at its peak) until 2003. Changes in nutrient and carbonconcentrations in the top layer of sediments were investigated in parallel with macroalga land seagrassbiomass in the most anthropized basin of Venice Lagoon in four surveys conducted in accordance with the same protocols in 1987, 1993, 1998, and 2003. A pronounced reduction in trophic state (mainly total nitrogen, organic phosphorus, and organic carbon concentrations) and macroalgal biomass was recorded, together with the progressive expansion of seagrass meadows. General consideration sare also made on the effects of Manila clam farming and the shift from illegal to managed clam farming.