Abstract
Background
Molluscs, especially, octopus is a nutritious seafood, containing high levels of proteins, omega-3 fatty acids, and essential minerals. However, marine pollution with heavy metals such as mercury (Hg), lead, and cadmium (Cd) is a growing concern, as these elements can accumulate in octopus tissues as a result of the marine food chain.

Aim:
This study aimed to determine the from beaches near the Zawiya refinery and compare them with samples taken from beaches far from industrial cities (Marsa Zawagha/b).

Methods:
Hg concentrations (mg/kg wet weight) were measured using the Buck Scientific USA 210 VGP model Atomic Absorption Spectrophotometer at the Central Laboratory of Delta Technical Services Company, Tripoli, Libya, in accordance with Association of Official Analytical Chemists (1990).

Results:
The results were average concentrations of 0.0336 and 0.1576 mg/kg in liver and arm samples taken from Zawiya, respectively, and 0.0050 and 0.0069 mg/kg were detected in liver and arm samples taken from Marsa Zawagha, respectively. Below the internationally recommended level (0.5 mg/kg) according to the World Health Organization and the European Union.

Conclusion:
The amount was within permissible bounds. Statistical analysis, that the Zawia Refinery area has a statistically significant (p < 0.05) advantage over Marsa Zawagha in terms of the (mg/kg) in liver samples. Additionally, average concentrations for both areas were below the World Health Organization and European Union standards (<0.5 mg/kg).

Key words: Octopus; Mercury; Atomic Absorption Spectrometer; Zawiya refinery; Marsa Zawagha Sabratha.