Role of hydrographical parameters and total organic carbon on mercury allocation along the riverine transect of Beypore, south-west coast of India

Abstract

Distribution of total mercury (THg) was carried out in the sediments of Beypore estuary. The THg concentration in surface sediments varied from 0.03 ppm to 0.17 ppm. The pollution index approach using contamination factor (CF) revealed that the sampling stations are moderately contaminated with respect to mercury. Further, the effects of hydrographical parameters (pH, salinity, dissolved oxygen) and total organic carbon (TOC) of the sediment were studied over the spatial distribution of mercury (Hg). Correlation analysis unveiled THg exhibited significant positive correlations with TOC (R=0.91) and salinity (R=0.744). However significant inverse correlation was observed between pH and Hg (R =-0.93). The C: N ratios suggest that the organic matter is labile in nature. Total organic carbon was found to control the distribution of Hg. It is the first base line study in this estuary.