Trace element bioaccumulation in the seagrass Cymodocea nodosa from a polluted coastal lagoon: Biomonitoring implications

This is the first investigation of the potential for using Cymodocea nodosa to biomonitor trace element (TE) contamination in Marchica lagoon (Morocco), a Mediterranean pollution hotspot. We measured concentrations of seven TEs in seagrass tissues (leaf-rhizome-root) and sediments. Single and multi-element indices confirmed that sediments near illegal discharges were heavily polluted and we predicted risks of frequent adverse biological effects in these areas. Four of the TEs increased concentrations in C. nodosa leaf and root along sediment pollution gradient. Leaves and roots were both good indicators of Cu and Cd contamination in sediment, whereas leaves were the best indicator of Zn and roots for Pb. This seagrass was not a bioindicator of Al, Cr and Ni contamination. These results show the bioaccumulation patterns of TEs in C. nodosa, and can be used to design biomonitoring programs.

Automated summary

The study revealed that Cymodocea nodosa can be used to monitor trace element pollution in the Marchica lagoon, with sediments near illegal discharges being heavily contaminated. Leaves and roots of the seagrass are good indicators of contamination, and can be used to design biomonitoring programs.