Polycyclic Aromatic Hydrocarbons (PAHs) in Plants of Shadegan Wetland: Halocnemum strobilaceum and Suaeda maritima

Plants are known to bioaccumulate many contaminants. Petroleum-derived compounds, such as saturated hydrocarbons and PAHs are widespread persistent environmental contaminants. Deposition of soot and precipitation of black rain have occurred in the Shadegan Wetland. In this study, PAHs in plant parts of two prominent species of halophytes, Halocnemum strobilaceum and Suaeda maritima were determined. PAHs were found in plant parts of H. strobilaceum and S. maritima. PAHs quantities differed significantly between shoots and roots of plants and between H. strobilaceum and S. maritima. Concentration of these compounds was greater in plants growing in the southern part of the wetland (south of Abadan-Mahshar road) than those growing at the northern part. This finding corroborates findings of investigation on prevalence of heavy metals associated with crude oil; for example, Ni and V in sediments of Shadegan wetland. Detecting PAHs in plant organs indicates the potential for their bioaccumulation and transfer in trophic levels in the the food chain. Although, determining threshold levels for ill-effects of PAHs, such as reduction in vegetation coverage area, plant growth and development, physiological and metabolic changes as well as changes in biodiversity indices, require further investigation, the bioaccumulation by plants and subsequent removal of such plants from contaminated areas, the wetland ecosystem could recover itself in few years.