Metals are micropollutants of significant concern in the aquatic environment, requiring continuous monitoring to assess their distribution and environmental risk. This study investigated metals in water, sediment, and bivalves at different locations along the Scheldt estuary (the Netherlands-Belgium). The distribution of metals generally decreased from upstream to downstream in each matrix, with exceptions. In water, significant spatial differences were observed for Pb, Cu, and Ni, with the highest median concentrations of 0.28 μg/L for Pb, 2.17 μg/L for Cu, and 1.53 μg/L for Ni. In sediment, the highest median concentrations were observed for Zn (213 μg/g dw), followed by Cr (73 μg/g dw), Pb (60.5 μg/g dw), Cu (36.5 μg/g dw), Ni (21 μg/g dw), Co (9.1 μg/g dw), and Ag (0.9 μg/g dw). Similarly, the highest median concentrations in bivalves were observed for Zn (319 μg/g dw), followed by Cr (10.9 μg/g dw), Pb (9.6 μg/g dw), Ni (7.2 μg/g dw), and Ag (0.75 μg/g dw). Significant spatial variations were observed for all metals in sediment and bivalves, except for Co in sediment and Ag in bivalves. All metals in the sediment showed a significant correlation with total organic carbon and clay content (r = 0.5-0.87
p <
0.05). The temporal investigation showed a decline for Cu, Cd, Pb, and Zn in sediment. Concentrations of Pb, Cr, and Cd in sediment exceeded the sediment quality standards of 35.8, 0.99, and 43.4 μg/g dw, respectively. Future monitoring should account for estuarine dynamics by including tidal cycles and investigating seasonal variations.