Brown Algae as Biomonitors of Heavy Metal Pollution along the Saudi Coast of the Arabian Gulf

Abstract

Four species of brown algae (Phaeophyta) were collected from Al-Khafji and Al-Dammam areas on the Saudi coast of the Arabian Gulf. The algal samples were dry digested. The concentrations of Cd, Cu, Fe, Pb and Zn were measured in the aliquot samples of the algae using Atomic Absorption Spectrophotometer. Normal levels were found for Cd, Cu and Zn. The average concentration of these metals ranged between 0.62 and 1.95 μg g-1 for Cd, 3.95 and 11.23 μg g-1 for Cu and 15.70 and 75.25 μg g-1 for Zn. High burden of Fe (161-1,466 μg g-1) and Pb (8.84-18.60 μg g-1) were found in the four algae at both sites. The highest levels of Cd and Cu were found at Al-Khafji area, whereas elevated concentrations of Fe and Zn were obtained from Al-Dammam area. Lead levels were high at both sites. There is evidence of heavy metal contamination, especially with Fe and Pb, at both areas. Among the studied algae, the highest levels of Cd, Cu, Fe and Pb were detected in Padina gymnospora and this species could be used for monitoring coastal waters in the Arabian Gulf.

Key words: Brown algae, Heavy metals, Biomonitoring, Arabian Gulf, Saudi Arabia.