High temperature and solar radiation in the Red Sea enhance the dissolution of crude oil from surface films

• Published in: Environmental science and pollution research international 2024-06, Vol.31 (29), p.42034-42048
• Main Authors: Kottuparambil, Sreejith, Ashok, Ananya, López, Patricia, Amad, Maan H., Duarte, Carlos M., Agusti, Susana
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Biodegradation; Biodiversity; Biodiversity hot spots; Carbon; Carbon 13; Carbon dioxide; Chemical analysis; Composition; Crude oil; Dissolution; Dissolved organic matter; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; High temperature; Hot Temperature; Indian Ocean; Nucleic acids; Oil pollution; Oil slicks; Oil spills; Organic carbon; Petroleum; Petroleum Pollution; Photochemicals; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - chemistry; Radiation; Research Article; Seawater; Seawater - chemistry; Solar radiation; Sunlight; Temperature effects; Total organic carbon; Waste Water Technology; Water analysis; Water Management; Water Pollutants, Chemical - chemistry; Water Pollution Control
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-024-33864-z

The Red Sea is a hotspot of biodiversity susceptible to oil pollution. Besides, it is one of the warmest seas on the Earth with highly transparent waters. In this study, we estimated the oil dissolution rates under natural sunlight spectra and temperature conditions using coastal oil slicks collected after the 2019 Sabiti oil spill in the Red Sea. Optical analyses revealed the significant interactive effect of sunlight and temperature in enhancing the dissolution of oil into dissolved organic matter (DOM). The highest oil dissolution rate (38.68 g C m −3 d −1 ) was observed in full-spectrum sunlight. Oil dissolution significantly enhanced total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) in seawater. High nucleic acid (HNA) bacteria, likely the oil degraders, proliferated from 30 to 70 – 90% after 4 days. The heavier stable carbon isotopic composition of methane (δ 13 C-CH 4 ) and lighter stable carbon isotopic composition of carbon dioxide (δ 13 C-CO 2 ) indicate the putative role of bacterial processes in the natural degradation of crude oil. The results indicated that the combined effect of temperature and solar radiation enhanced the biological and photochemical dissolution of oil on the Red Sea surface.