Sunken oil mats: A biomarker-based investigation

Author(s)

Lourenco, Rafael Andre ; Marcelino, Rafael Patrick R. ; Lube, Gabrielle Vieira ; Lassalle, Guillaume ; Scafutto, Rebecca Del'Papa Moreira ; de Souza Filho, Carlos Roberto

• Document type: Journal article
• Source: Marine Pollution Bulletin; v. 208, p. 6-pg., 2024-09-17.

Abstract

Sunken oil mats (SOMs) pose a significant threat to marine ecosystems, yet their long-term fate and weathering processes remain poorly understood. This study investigates the degradation of biomarkers in a SOM sample collected from the Brazilian coast following the long-lasting 2019 oil spill. The SOM clearly distinguished from spilt oil and were attributed to tanker-washing residues. Analysis of its sections revealed a consistent depletion pattern, associated with losses of volatile and photooxidation-sensitive compounds, even in the most preserved inner fractions, this suggests weathering of the oil prior SOM formation. While biodegradation was minor, photooxidation revealed a significant weathering factor, especially for aromatic compounds as indicated by preferential degradation of highly-alkylated tricyclic aromatic sulfur heterocycles, and specific methylpyrenes and benzofluorenes. This study underscore the complex interplay of weathering processes shaping the fate of SOMs and the importance of biomarker-based diagnosis in assessing the origin and ecological impacts of longlasting oil spills. (AU)

• FAPESP's process: 22/14244-8 - Determination of biogenic sterols in an Antarctic environment, over the last 20 years, and the relationship with recent environmental changes.
• Grantee: Gabrielle Vieira Lube
• Support Opportunities: Scholarships in Brazil - Master