high content of heavy metals in seaweed species: A case study in the Persian Gulf and the Gulf of Oman in the southern coast of Iran

The contamination of heavy metals is a serious environmental challenge which threatens human health through food chain. This study focused on pollution level of six heavy metals (Cu, Zn, Pb, Ni, Fe^+2, and Cd) by investigating 12 seaweed species collected from different intertidal areas in the Persian Gulf and the Gulf of Oman. In addition, the uptakes of heavy metals in seaweed species were examined. The results confirmed the heavy metals contamination in the studied seaweed species. In addition, the uptake level was affected by the type of heavy metal (P ≤ 0.0001). Additionally, the type of seaweed species and collection site affected the heavy metal uptake. Accordingly, the highest content of Fe+2 (2844 ppm) was found in Dictyota sp. and Nickel (Ni) was observed in Padina gymnospora (105.97 ppm) and Hypnea sp. (100.41 ppm). Furthermore, the highest concentrations of Zinc (58.46 ppm) and Copper (32.44 ppm) were found in Sargassum angustifolium, and S. boveanum, respectively. Additionally, Cadmium had the lowest concentration ranging from 4.8 ppm in S. angustifolium to 10.7 ppm in Dictyota sp. The lowest content of all tested heavy metals was observed in Gracilariopsis persica. Further, the results revealed that brown macroalgae (Phaeophyta) contaminated more than green (Chlorophyta) and red (Rhodophyta) macroalgae.