Biomonitoring using Biomarkers is essential for evaluating the environmental contamination, especially if combined with chemical analysis. This study aims to provide an integrated assessment of environmental quality at 8 sites along the northwestern Atlantic coast of Morocco by analyzing 10 trace metal concentrations in Mytilus galloprovincialis and evaluating their biological effects through a multibiomarker approach, pollution indices, and human health risk assessment, thereby highlighting early biological effects that may not be detectable through chemical data alone. Biomarkers of neurotoxicity, oxidative stress, and detoxification were assessed alongside pollution indices and condition indices to determine site-specific variations in mussel health, while measured metal concentrations were compared with international background and guideline values (WMW, NS&T, RNO) to contextualize contamination levels. The results showed that trace metal concentrations decreased in the order: Fe > Zn > Mn > As>Cu > Ni > Pb > Cd > Co > Hg but were within regulatory safety limits for most of the study sites. Biomarker responses revealed localized environmental stress, particularly at sites influenced by urban–industrial activities (notably S3, S5, and S6), where elevated bioaccumulation of Ni, Zn, Cd, and Pb coincided with increased enzymatic and stress responses. The integration of chemical and biological data provided a comprehensive assessment of contamination, demonstrating that multibiomarker approaches provide sensitive early-warning signals of environmental stress in coastal ecosystems, even when trace metal concentrations remain largely within regulatory limits, thereby confirming that biomonitoring is essential for detecting early signs of pollution before metal levels reach critical thresholds and emphasizing their relevance for environmental management and marine biosurveillance programs.
Benrahma et al. (Mon,) studied this question.