Elemental Composition of Core Sediments in Niger Delta Mangrove, Nigeria

Abstract

Mangrove core sediments from Choba, Ogbogoro and Isaka in Niger Delta, Nigeria were analyzed to determine their geochemical composition. The ecological risk of the metal concentrations was assessed using Contamination Factor (CF) and Enrichment Factor (EF) while the quality of the sediments was determined using sediment quality guidelines. The results indicated contrasting metal concentrations with depth and location as shown by the box plots and cross sectional graphs. The average concentration of Pb, Zn, Cu, Ni, Cr, V, Nb and Th were found to be most abundant in Choba while As, Sr and TS were most concentrated in Ogbogoro. Compared with the upper continental crust (UCC) values, As, Ni, Cr and V were higher in all the sampled locations. Pb and Th were higher in Choba and Ogbogoro while Zn, Cu and Nb were higher only in Choba. The concentration of biogenic and provenance metals in Isaka are largely geogenic due to strong TiO2  association with Pb, Zn, Cu, Ni, Cr, V, Sr, Nb and Th. As enrichment in Choba, Ogbogoro and Isaka is anthropogenic. Comparison with the sediment quality guidelines showed that Ni impact in Choba is severe while Cr concentration level in Choba, Ogbogoro and Isaka might have adverse ecotoxic impact on biota.