AIM: The present work aimed to determine the concentrations of mercury (Hg(+2)) in fish, marine plants and sediment collected from Farwa lagoon to evaluate effect of industrial wastewater from GCCI on the marine environment.

METHODS: Hundred and twelve samples of fish, pearl oyster, cuttlefish sediments and marine plants were analyzed to determine Hg(2+) concentration during the period from January to August 2014 by using Atomic Absorption Spectrometer (AAS).

RESULTS: The highest concentration of Hg(2+) was detected in Pinctada radiata (11.67 ± 3.30 μgg (-1)) followed by Serranus scriba (6.37 ± 0.11 μg g (-1)) and Epinephelus marginatus (6.19 ± 0.02 μg g (-1)). About 75 % of marine plants contained the maximum contaminations during the summer season. In fish samples Hg(2+) concentrations exceeded the levels provided by international standards.