The historical practice of disposal of dredged sediments in the Marano and Grado Lagoon: evaluation of geomorphological, evolutionary and functional perspective of the resulting artificial saltmarshes

An inventory was conducted of the present saltmarshes whose origin is due to the dredging and sediment disposal subsequent to an important waterway carried out in the early 1900 in the Marano and Grado Lagoon, a Special Area of Conservation (SAC) located in the northern Adriatic Sea. Morphology, evolution and habitat distribution were investigated by means of field surveys and topological analysis in GIS, using air photo for the period 1954-2011. Considering the overall maintenance of saltmarshes after 57 years since the sediment disposal, the frequent presence of near-natural morphologies and the subsequent development of Natura 2000 habitats, it is possible to state that building saltmarshes with dredged sediment has achieved good results during time. The historical practice of re-using dredged sediments for morphological and habitat restoration could be re-proposed as best practice for an effective conservation and management of the lagoon.