Sources and distribution of organic matter and polycyclic aromatic hydrocarbons in sediments of the southwestern Portuguese shelf

Mário Mil-Homens; Sofia Gonçalves; Alejandro Cortés; Barend L van Drooge; Henko de Stigter; Joan O Grimalt; Lívia Gebara Cordeiro; Miguel M Santos; C Marisa R Almeida; Miguel Caetano

doi:10.1016/j.marpolbul.2024.117303

Sources and distribution of organic matter and polycyclic aromatic hydrocarbons in sediments of the southwestern Portuguese shelf

Mar Pollut Bull. 2025 Jan:210:117303. doi: 10.1016/j.marpolbul.2024.117303. Epub 2024 Nov 25.

Affiliations

¹ IPMA, Divisão de Oceanografia e Ambiente Marinho, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Algés, Portugal; CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal. Electronic address: [email protected].
² CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.
³ Institute of Environmental Assessment and Water Research (IDAEA-CSIC), c/Jordi Girona, 18-26, 08034 Barcelona, Catalonia, Spain.
⁴ NIOZ, Royal Netherlands Institute for Sea Research, Department of Ocean Systems, Landsdiep 4, 1797SZ 't Horntje, Texel, the Netherlands.
⁵ IPMA, Divisão de Geologia e Georecursos Marinhos, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Algés, Portugal; CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
⁶ CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
⁷ CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
⁸ IPMA, Divisão de Oceanografia e Ambiente Marinho, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Algés, Portugal; CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.

PMID: 39591679
DOI: 10.1016/j.marpolbul.2024.117303

Abstract

Total organic carbon (C_org), total nitrogen (N_tot), C_org/N_tot, δ¹³C_org, δ¹⁵N, calcium carbonate (CaCO₃), and grain size were analyzed in 70 surface samples and 19 short cores from the southwestern Portuguese shelf. Perylene and USEPA-16 PAHs were quantified in a subset of these samples. The findings suggest that organic matter derives from a mix of terrestrial and marine sources, outlined by C_org, N_tot, and isotopic signatures. Perylene combined with δ¹³C_org was used to identify the main PAH sources in these environments. Diagnostic perylene ratios revealed contributions from natural sources in the Tagus region and contaminated materials from the Sado Dredged Disposal Site, with additional perylene in Sines linked to atmospheric deposition of pyrogenic sources. A significant correlation between perylene and USEPA-16 PAHs indicates natural and anthropogenic inputs from the Tagus. This multiproxy approach-combining USEPA-16ΣPAHs, perylene, and δ¹³C_org-offers insights for assessing environmental risks and guiding marine environmental management according to the MSFD.

Keywords: Marine sediments; Organic matter composition; Perylene; Stable carbon and nitrogen isotopes; USEPA-16ΣPAHs.

MeSH terms

Carbon / analysis
Environmental Monitoring*
Geologic Sediments* / chemistry
Nitrogen / analysis
Polycyclic Aromatic Hydrocarbons* / analysis
Portugal
Water Pollutants, Chemical* / analysis

Substances

Polycyclic Aromatic Hydrocarbons
Water Pollutants, Chemical
Nitrogen
Carbon