Trace metal distribution and ecological risk assessment in the core sediments of a highly urbanized tropical mangrove ecosystem, Southwest coast of India

K S Moushmi; Anu Susan Cheriyan; Eldhose Cheriyan; Manu Mohan; N Chandramohanakumar

doi:10.1016/j.marpolbul.2021.113163

Trace metal distribution and ecological risk assessment in the core sediments of a highly urbanized tropical mangrove ecosystem, Southwest coast of India

Mar Pollut Bull. 2022 Feb:175:113163. doi: 10.1016/j.marpolbul.2021.113163. Epub 2021 Nov 24.

Authors

K S Moushmi¹, Anu Susan Cheriyan², Eldhose Cheriyan¹, Manu Mohan¹, N Chandramohanakumar³

Affiliations

¹ Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi 682016, India.
² Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi 682016, India. Electronic address: anususan@cusat.ac.in.
³ Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Kochi 682016, India; Inter University Centre for Development of Marine Biotechnology, School of Marine Sciences, Cochin University of Science and Technology, Kochi 682016, India.

PMID: 34838287
DOI: 10.1016/j.marpolbul.2021.113163

Abstract

Distribution and ecological risk assessment of trace metals were carried out in the core sediments of a highly urbanized tropical mangrove ecosystem along the Southwest coast of India. The metal distribution pattern was as follows: Co, Cu, Ni and Pb adsorbed onto Fe oxyhydroxides and fine grained sediments; Cd and Zn preferential adsorption by organic matter and Cr scavenging by Mn oxyhydroxides. Cd, Pb and Zn were significantly enriched in upper sediments, while Cd, Ni and Zn were present in metal exchangeable fractions. Geoaccumulation index (I_geo) suggested that the study area showed moderate to strong pollution of Cd and Zn, whereas unpolluted to moderately polluted with respect to Co, Cr, Cu, Mn, Ni and Pb. Cd enrichment caused high ecological risk, primarily attributed to anthropogenic activities. Mangrove ecosystems are efficient sequester of trace metals but anthropogenic addition can cause significant fraction of exchangeable metals and pose high ecological risk.

Keywords: Core sediments; Mangrove ecosystem; Organic matter; Risk assessment; Trace metal.

MeSH terms

Ecosystem
Environmental Monitoring / methods
Geologic Sediments
India
Metals, Heavy* / analysis
Risk Assessment
Water Pollutants, Chemical* / analysis

Substances

Metals, Heavy
Water Pollutants, Chemical