Spatial and seasonal trends of trace metals in the surficial sediments from off Kochi - Geochemistry and environmental implications

Fifty four sediment samples representing pre and post-monsoon seasons were collected along a transect from off Kochi, lying between the latitudes 9°57′59.5″-9°54′30.4″ and longitudes 76°11′7.04″-75°38′50.3″ of the South eastern Arabian Sea. The present study investigates the levels of trace metals (Zn, Cd, Pb, Cu, Fe, Ni, Mn, Co and Cr), total organic carbon (TOC), total inorganic carbon (TIC), elemental composition and grain size to assess the extent of environmental pollution and to discuss the distribution of these trace metals in the surficial sediments. Sediment pollution assessment was done using the Contamination factor (C.F), Geoaccumulation Index (Igeo), Enrichment Factor (EF), and Pollution Load Index (PLI). The majority of trace metals analysed in this study exhibited the highest concentrations at stations 1, 2 and 3 where the land-based anthropogenic input was found to be maximum. •This study assessed spatial and temporal variation of trace metals, TOC, TIC, elemental composition and grain size in off Kochi sediments.•The majority of trace metals in this study exhibited the highest concentrations at stations 1, 2 and 3 where the land-based anthropogenic input was maximum.•According to the contamination factor, the coastal environment was moderately polluted with Ni, Cr and Zn.•The results draw special attention to Cochin, the second biggest industrial city along the west coast of India.