Risk assessment of heavy metals in mangrove trees (Avicennia marina) and associated sea water of Ras Mohammed Protectorate, Red Sea, Egypt

Abstract

The environmental condition of marine environment is rapidly deteriorating due to current population and development patterns. Marine protected areas (MPAs) are an approach to managing the oceans more sustainably. MPAs are places that have been legally recognized as being for the protection and conservation of valuable biodiversity, together with associated ecosystem services and cultural values. Seven sampling stations of sea water were selected as well as 62 mangrove samples were collected from these seven stations along the Ras Mohammed protectorate coast. The distribution of heavy metals as µg/L in water samples was in the following order Fe>Zn>Pb>Cu>Mn>Cd. The Enrichment Factor (EF) of Fe, Cd, Cu, Zn, Mn, and Pb in Ras Mohammed protectorate was slight, with values lower than 1 at all locations. In addition, the area of study was slightly affected by the metal pollution index (MPI) as it is located in class III (between 1-2 levels). Also, this study determined concentrations of these metals in three parts of Avicennia marina (leaves, stem, roots). The results showed that the concentrations of metals were ordered from high to low concentrations as follows roots>leaves>stem. Manganese was the highest concentration in bioconcentration factor among the elements examined in the roots, leaves, and stem of Avicennia marina.