Application of biomarkers in brown algae (Cystoseria indica) to assess heavy metals (Cd, Cu, Zn, Pb, Hg, Ni, Cr) pollution in the northern coasts of the Gulf of Oman

In this study, selected biomarkers-Phytochelatin (PC) and Metallothionein (MT)-were measured in the brown algae (i.e., Cystoseria indica) obtained from the Gulf of Oman. Chemical analyses were performed to measure the concentration of heavy metals (Cd, Cu, Zn, Pb, Hg, Ni, and Cr) in the brown algae. Zn had the highest concentration followed by Cr > Ni > Cu > Pb > Cd > Hg. Performing a spatial analysis revealed that heavy metals had a significant difference (p < 0.05) among sampling sites. Mean PC and MT ranged between 5 and 13 amol/ cell and 105-134 mu g/g ww, respectively. Significant correlations were found between heavy metal (Cd, Cu, Zn, Pb, Ni, and Cr) concentrations and MT. However, statistically significant correlations were only found between heavy metals (Cd, Zn) and PC (p < 0.01). The results showed that PC reacts to heavy metals less than MT in brown algae (C. indica) which limits the use of PC in heavy metals biomonitoring.