Seasonal Variations and Multivariate Assessment of Trace Metals in Mussels (Mytilus galloprovincialis, Lamarck, 1819) from the Algerian West Coast

This study investigated the seasonal variation and spatial distribution of four trace metals—zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb)—in the soft tissues of the mussel Mytilus galloprovincialis, collected from six coastal sites along the Algerian west coast. This region, rich and ecologically diverse, is marked by a high population density and significant anthropogenic activity. Mussel samples were collected between June 2023 and May 2024, and trace metal concentrations were determined using flame atomic absorption spectrophotometry. The highest Zn concentration was recorded in summer (34.27 ppm F.W), while Cd peaked in both spring and summer (0.076ppm F.W). Cu and Pb reached their highest values in autumn, at 0.953ppm and 0.214ppm F.W, respectively. Statistical analyses, including Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (CAH), were employed to identify patterns of metal accumulation and the influence of environmental factors. Analysis of Variance (ANOVA) revealed significant seasonal variation for Zn and Cd (F= 8.45, P< 0.001 and F= 6.78, P= 0.0024, respectively), particularly in spring and summer. PCA results showed strong associations among Zn, Cd, and Cu, while CAH distinctly grouped sampling sites by season, notably highlighting autumn samples. The correlation matrix revealed meaningful relationships between physicochemical parameters and metal concentrations, especially a strong inverse correlation between dissolved oxygen and Cd. These findings underscore the role of environmental factors in influencing metal bioaccumulation and offer important insights for coastal pollution monitoring and environmental management strategies in the Algerian west coast region.