Abstract

  Most sediment dredged in Italian harbours is discharged into coastal areas. Italian legislation provides physical and chemical characterisation of dredged material. However, to determine whether materials are discharged to a dumping site, used for coastal nourishment or other beneficial use, toxicological assessment should be required. In 1995, 12 sediment cores were taken from dredged areas of Viareggio harbour (Tyrrhenian coast). Nine superficial sediments were collected in two coastal areas: a disposal site and a potential nourishment site. Particle size, total organic matter, heavy metals, polycyclic aromatic hydrocarbons and polychlorinated biphenyls were analysed. In order to assess sediment toxicity and evaluate the best destination, Lee bioassays were performed on two harbour and one offshore superficial samples using Vibrio fisheri, Corophium volutator and larvae of Crassostrea gigas.
  The different harbour areas showed an increase of contaminant levels from the entrance to the inner zones. A comparison of sediment quality of the harbour and coastal areas (physical, chemical and ecotoxicological characteristics) suggested that materials dredged from different areas should be handled in different ways depending on contaminant types and loads. Dredged sediments could be dumped off-shore without decontamination or further use, used to build up eroded areas or be subjected to i-site decontamination treatment. © 1999 Elsevier Science Ltd and AEHMS. All rights reserved.

Keywords: Contaminants; Bioassay; Vibrio fisheri; Corophium volutator, Crassostrea gigas;                  Tyrrhenian sea