Trace Metals Content in Annually-Banded Scleractinian Coral ‘Porites Lobata’ Across the Northern Persian Gulf

Abstract

Concentration of trace metals in skeleton growth bands of dominant scleractinian coral ‘Porites lobata’ were investigated in Kharg and Hebourabi islands across the northern Persian Gulf. The highest average concentration of elements were as Sr> Mg> Zn> Ba> Cu> U> Ni> Mn> Cr> Co> Pb> V> Cd in Kharg Island respectively and as Sr> Mg> Ba> Cu> U> Ni> Zn> Mn> Cr> Co> V> Pb> Cd in Hendourabi Island. Except for Cr, the concentrations of other trace metals in Kharg Island were higher than those of Hendourabi Island. The coefficient of variation percentage (CV%) for Cr, Mn, Zn, Ba and Pb in Kharg Island and for Cu and Ba in Hendourabi Island was more than 50%. Results of PCA analyses revealed that the trace metals Kharg Island was defined by three principal components including the first component (Mn, V, Pb, Zn, Ni and half of Mg, Cr and Co) corresponding to the past regional military conflicts and oil pollution, second component (Sr, U and Mg) corresponding to SST changes, and the third component (Cr and Co) corresponding to other factors. Results of PCA analyses revealed that trace metals in Hendourabi Island was defined by two principal components including first component (Co, Ni, Cr, Mn and half of Ba) corresponding to annual precipitation changes and the second component (U, Zn and Ba) corresponding to coastal constructions.