Geochemical Characterization of Sediments from the Bibione Coastal Area (Northeast Italy): Details on Bulk Composition and Particle Size Distribution

The aim of this study is to characterize the sediments of the coastal area of Bibione and the Baseleghe Lagoon (Province of Venice, Italy). The characterization includes the assessment of particle size distribution, carbonate content, composition of major oxides, and heavy metal concentrations. The results indicated that the sediments primarily consisted of carbonate but showed significant heterogeneity in both composition and grain size within the different environments of the Bibione coastal area. Carbonate content decreased from the beach to the seabed, which does not appear to be solely influenced by variations in sediment grain size. This finding has potential implications for the Bibione area’s coastal erosion processes and sediment quality. Significant differences in grain size and composition were observed between the mouth and the inner region in the lagoon area. The textural characteristics of the sediments in the inner part of the lagoon make it particularly vulnerable to pollution, with potential environmental and economic consequences. Different pollution indices have indicated the presence of heavy metal contamination in both the coastal and, especially, the lagoon area. The source of these metals appears to be predominantly natural, although there may be some contribution from anthropogenic sources for certain metals. However, the comparison of the metal concentrations in the samples with the limits set by the Italian legislation showed that the sediments were still of good quality.