Ship-wake induced sediment remobilization: Effects and proposed management strategies for the Venice Lagoon

More than 3000 commercial vessels navigate through the Malamocco-Marghera Industrial Canal in Venice Lagoon, Italy in a given year, leading to an estimated annual resuspension of 1.2 x 10(6) metric tons of sediment. Hence, ship wakes contribute to the significant erosion of shoals in the central lagoon which has occurred over the last 30 years. Drawdown associated with the surface depression wave from successive ships induces sediment transport towards the shipping canal, where the cost of dredging amounts to tens of millions of Euro per year. Most ship traffic occurs near an industrial zone, resulting in substantial potential for resuspension of contaminated sediment. Thus, sediment resuspension by ship traffic in the Venice Lagoon has the potential for detrimental economic and environmental impacts.