BIO-GEOCHEMICAL STUDIES OF INDUS DELTA MANGROVE ECOSYSTEM THROUGH HEAVY METAL ASSESSMENT

Abstract

In the present study monitoring of heavy metal pollution was done in the mangrove habitats of Indus Delta. Different levels of four heavy metal (Pb, Cu, Cd, and Zn) in abiotic component (sediments and water) and biotic components (mangrove plants parts like, (Pneumatophores, bark, leaves, flowers, and fruits) were determined. The highest average concentration of heavy metals (111 ppm Zn, 60.0 ppm Pb, 52.2 ppm Cu, 1.43 ppm Cd) were measured in sediments and the lowest in the water (0.13 ppm Zn, 0.0014 ppm Cu, 0.0007 ppm Pb , 0.00061ppm Cd). Among the four heavy metals, Zn was the most abundant metal in all components of the ecosystem, followed by Cu, Pb, and Cd (Zn>Cu>Pb>Cd), and hence A. marina can be proposed as a hyper-accumulator for Zn, which opens doors for further research. The pollution load index (PLI) had values higher than 1 and varied between 2.02-1.70 at Indus Delta, whereas at MianiHor the PLI was 0.65, which indicated that Indus Delta mangrove Ecosystem was under threat of pollution under the present scenario.