Environmental risk assessment of the Moroccan Atlantic continental shelf: The role of the industrial and urban area

- Natural and anthropic inputs contribute to heavy metal pollution in shelf sediment.
- Metal distribution is under dual control sediment facies and marine currents.
- Generally metals in sediments from the Moroccan shelf were not greatly enriched.
- Stations close to urban and industrial areas have large concentrations of the metals.

The present research presents the first large-scale analysis of heavy metal assessment in the Moroccan Atlantic shelf. This work provides scientific basis for future studies on environmental research and fills the gap in knowledge on the worldwide continental platforms.Metal distributions identified three different zones, mainly influenced by industrial and urban sewer (northern areas), agriculture runoffs (central zone), and estuarine discharges (southern areas), respectively. In the north part of the shelf, metal enrichments are observed near industrial and urban sewer mouths (Casablanca and Mohammedia cities). In the south and central areas, the probable absence of human impact on sediments is attributed to effective trapping in the estuary (Oum Er Rbia) and coastal zones, as well as dilution with less contaminated sediments and shelf sediments and removal with fine fractions due to estuary discharges.