Baseline trace element concentrations in marine sediment from the West African coast

Abstract

Baseline studies play a crucial role as tools for environmental reconstructions and assessments, and guide future actions aimed at the restoration and preservation of marine ecosystems. Major and trace elements (TE) were determined in five sediment cores collected in the Angolan and Namibian coastal waters. Predominantly homogeneous vertical profiles indicate that natural sources control levels of TE in sediments. Enrichment Factors (EF) and the Geo Accumulation Index corroborate this hypothesis. Nevertheless, among potentially toxic elements, Cr was found in high concentrations in sediment (up to 640 mg kg−1), surpassing sediment benchmarks in almost all samples. This is likely ascribable to naturally occurring minerals rather than anthropogenic inputs, based on our current knowledge. In the cores near the Namibian coast, shale-normalized rare earth elements (REE) were slightly enriched in heavy rare earth elements (HREE), while in Angola the pattern was enriched in the light REE (LREE). The Pb isotopic composition of sediment was found to resemble that measured in uncontaminated sediments from Namibia (average 206Pb/204Pb = 18.98, 208Pb/204Pb = 39.3) and are indicative of carbon-rich minerals from the region, further underscoring the natural sources of Pb.

Document Type

Journal Article

Date of Publication

6-1-2025

Volume

215

School

Centre for Marine Ecosystems Research / School of Science

Copyright

subscription content

Publisher

Elsevier

Identifier

Pere Masqué: https://orcid.org/0000-0002-1789-320X

Comments

Amideina, A., Orani, A. M., Azemard, S., Gasser, B., Masqué, P., Swarzenski, P., ... & Vassileva, E. (2025). Baseline trace element concentrations in marine sediment from the West African coast. Marine Pollution Bulletin, 215, 117926. https://doi.org/10.1016/j.marpolbul.2025.117926

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Link to publisher version (DOI)

10.1016/j.marpolbul.2025.117926