Mercury contamination at Vembanad Lake and near-shore regions in the southwest coast of India

• Published in: Regional studies in marine science 2021-05, Vol.44, p.101754, Article 101754
• Main Authors: Mohan, Mahesh, Chandran, M.S. Shylesh, Ramasamy, E.V.
• Format: Article
• Language: English
• Subjects: Bioaccumulation; Fish; Methylation; Pollution; Sediment; Speciation; Transformation
• ISSN: 2352-4855; 2352-4855
• DOI: 10.1016/j.rsma.2021.101754

Mercury (Hg) contamination in aquatic systems is a universal concern because of its persistence, bioaccumulation, toxicity, and trans-boundary nature. The current study focuses on monitoring the fate and transport of Hg in aquatic matrices such as water, interstitial water, sediment and fish in a tropical coastal ecosystem. The cold vapour atomic fluorescence spectrometer was used for the Hg analysis. The study assessed the fractionation of Hg and its methylation potential in sediments. The high Hg concentration in fish tissues showed the ineffectiveness of biogeochemical control over the methyl Hg mobility and bioavailability through the food web. Research results indicate that the accumulation potential of Hg subsequently increases along the food chain. The conducive physico-chemical environment at the sediment–water interface supports chemical transformations/transport of Hg from one matrix to the next. The fate of Hg in the lake has also been discussed based on the data generated. •Mercury content in various environmental matrices of a brackish water wetland ecosystem.•Speciation of mercury and accumulation in aquatic organisms.•Fate and transport of mercury in a tropical wetland ecosystem.