Abstract
Background:
Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent organic pollutants in coastal environments, posing a global concern because of their toxic, mutagenic, and carcinogenic effects on marine ecosystems and food safety.

Aim:
This study investigates the occurrence, bioaccumulation patterns, and ecological impacts of PAHs in seawater and tissues of Pagrus pagrus (common sea bream) inhabiting Benghazi Port, Libya.

Methods:
PAH concentrations were measured in water and fish tissues (gill and liver). Correlation analysis and principal component analysis were used to identify potential contamination sources, and findings were compared with regional benchmarks and European Food Safety Authority (EFSA) safety thresholds.

Results:
The water samples revealed variable PAH levels, with Benzo[ghi]perylene (BghiP) exhibiting the highest concentration (11.866 ppb), followed by Benzo[b]fluoranthene (2.941ppb) and Benzo[a]anthracene (2.914ppb). Moderate levels of other high-molecular-weight PAHs. In fish tissues, PAHs were more concentrated in the liver than in the muscles, with BghiP levels ranging from 12 to 15 ppb, indicating significant bioaccumulation. Correlation analysis suggested that the primary source of heavier PAHs was thermal decomposition—likely from ship wasts and fuel combustion whereas lighter PAHs were attributed to petroleum-related input . Histopathological examination revealed focal hepatitis in the liver, marked by leukocyte infiltration and hepatocellular degeneration. Gill tissue exhibited severe lesions, including inflammation, epithelial hyperplasia, and early lamellar fusion, highlighting the detrimental effects of environmental pollutants on fish health.

Conclusion:
Comparative analysis with regional data indicates that Benghazi Port experiences moderate PAH contamination. Although bioaccumulation was observed in P. pagrus, the detected concentrations remained below the safety threshold established by the European Food Safety Authority. These findings highlight the need for sustained monitoring programs and effective management strategies to mitigate human-induced pollution in marine coastal environments.

Key words: Benghazi Port; Environmental risk; Pagrus pagrus; Polycyclic Aromatic Hydrocarbons; Water pollution.