An integrated approach to assess the benthic quality after sediment capping in Venice lagoon

Abstract

Abstract The present study was conducted in the Lago dei Teneri area of the Venice Lagoon in Italy. This area has long received massive pollutant input from the industrial area of Porto Marghera. It is adjacent to the Canale dei Petroli, an important industrial waterway. Because of its location, this area represents an ideal site for applying a new remedial solution: the capping of contaminated sediment with clean sand to support the benthic recolonization of the sediment. Capping was selected for this anoxic and most contaminated portion of the area as the most cost-effective way to provide a clean benthic habitat, to isolate the contamination and prevent contaminate release. An extensive sediment monitoring program was in place before, during and after the capping operations. Monitoring activities included hydrodynamics, measurement of cap thickness, in situ sediment profile imaging, benthos colonization, analysis of contaminants, and toxicity tests with Microtox and amphipods. To evaluate the efficiency of the capping, the results were analyzed with an integrated approach, which includes the Habitat Evaluation System. This approach allowed the quantification of the environmental benefits with respect to remediation of the Venice lagoon.