Scholarly record

BIOACCUMULATION OF PETROLEUM HYDROCARBONS IN SEDIMENT AND EDIBLE BIOTA FROM BILLE CREEK, RIVERS STATE, NIGERIA: CONTAMINATION LEVELS AND ECOLOGICAL IMPLICATIONS

Onyinyechi Grace Opara, Vsevolod V Pavshintsev

Abstract

Petroleum-related pollution remains a persistent threat to aquatic ecosystems in the Niger Delta, particularly in communities near active oil infrastructure. This study assessed total petroleum hydrocarbons (TPH), sixteen priority polycyclic aromatic hydrocarbons (PAHs), and selected 5 heavy metals (Chromium, Cadmium, Lead, Nickel and Zinc) in sediment and two edible benthic organism the periwinkle (Tympanotonus fuscatus) and the mangrove crab (Callinectes amnicola) samples collected at an oil company"s pipeline passage, having coordinates of N04.586789" and longitude of E6.888547, located in Bille community mangrove, Rivers State. Hydrocarbon-utilizing microorganisms in sediment were also enumerated. Mean TPH concentrations were 40.08 ± 7.68 mg/kg in sediment, 164.90 ± 0.50 mg/kg in periwinkle, and 224.05 ± 1.25 mg/kg in crab, indicating progressive bioaccumulation along the sediment-biota pathway. Low-molecular-weight PAHs, notably naphthalene and phenanthrene, were detected across matrices, whereas most high-molecular-weight congeners were below detection limits except in crab tissue. Among heavy metals, only zinc and nickel were detectable; cadmium, chromium, and lead were below instrument detection limits. Hydrocarbon-utilizing bacteria were present at 0.45 x 10/2 cfu/g, while fungi were negligible. Biota-sediment accumulation factors exceeded unity for TPH in both organisms (4.11 for periwinkle; 5.59 for crab), confirming active bioaccumulation. These findings demonstrate that petroleum contaminants are entering the food chain through commonly harvested species at Bille, posing potential risks to human consumers. This study confirms active TPH, low molecular weight (LMW) PAHs and trace Ni/Zn bioaccumulation, signaling ongoing pollution from oil operations, amplifying ecological stress in mangroves, risking biodiversity loss and food chain contamination. Limited microbial remediation underscores intervention needs. The research thereby recommends remediation, integrated ecological monitoring with regulatory enforcement to reduce pollution and its impacts, prevent resource degradation, and enable biodiversity conservation and ecosystem restoration and also not from compromising sustainability.

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