Available online Aug 21, 2025.

[ Original ] Volume 31, Issue 4, 2025, Pages 627-635

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Abstract

 

This study investigates the contamination of sediments along the Calabar River mudflats in southeastern Nigeria, based on hydrocarbon pollution from anthropogenic activities, such as industrial waste, untreated sewage, oil spills, and agricultural runoff. The aim is to assess the extent of contamination by examining the levels of total hydrocarbon content (THC), soluble organic matter (SOM), and petroleum-derived biomarkers at three locations: Adiabo Beach, Esuk Utan, and Nsidung Beach. Sediment samples were collected from these sites and analyzed for THC, SOM, and specific biomarkers using gas chromatography. Results indicate high levels of THC, with Esuk Utan exhibiting the highest concentration of 512.8 mg/kg, followed by Nsidung Beach (365.4 mg/kg), and Adiabo Beach (278.9 mg/kg). SOM values were similarly elevated, especially at Esuk Utan (15.4%), and the analysis of biomarkers revealed significant petroleum contamination, particularly at Esuk Utan, with a pristane/phytane ratio of 4.5, indicative of petroleum-derived hydrocarbons. The study shows that the sediment quality in the Calabar River mudflats is significantly impacted by various pollution sources, with Esuk Utan being the most affected. The results underscore the need for enhanced monitoring and management of industrial, sewage, and oil-related discharges in the region. A key recommendation is the need to implement strict regulations on industrial and sewage waste management in order to mitigate further ecological degradation and protect aquatic life.

 

 

Keywords

Geochemical analysis, petroleum contamination, Calabar River, mudflats, southeastern, Nigeria,

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