Heavy metal assessment in Nador lagoon (Mediterranean coast) was carried out using different
environmental indices. In addition, heavy metal concentrations were measured in sediment samples and
compared with consensus-based sediment quality guidelines. The spatial distributions of the main
contamination sources of heavy metals were identified and described using chemometric and geographic
information system methods.
The results show that heavy metals occur in lagoon sediments largely due to the anthropogenic
activities in the area (urban effluents). The concentrations of heavy metals found in surface sediments are
significantly higher than those from the local background. The potential ecological risk index and other
environmental indices produced similar values for the levels of heavy metal pollution in Nador lagoon
sediment, thereby confirming each other’s results. Pollution indices and statistical analysis show that the
heavy metals pose an ecological risk and indicate that Nador lagoon is moderately to considerably
pollute.