Grain size, geochemistry, magnetic susceptibility: Proxies in identifying sources and factors controlling distribution of metals in a tropical estuary, India

• Published in: Estuarine, coastal and shelf science Vol. 85; no. 2; pp. 307 - 318
• Main Authors: Dessai, Deepti V.G., Nayak, G.N., Basavaiah, N.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 10-11-2009; Elsevier
• Subjects: abundance; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Brackish; Brackish water ecosystems; Fundamental and applied biological sciences. Psychology; metals; seasonal distribution; sources and factors; Synecology; zuari estuary; Asia; India; ISW, India; ISW, India, Goa, Zuari Estuary; India, Goa, Zuari Estuary; metals; sources and factors; zuari estuary; abundance; seasonal distribution; Brackish water environment; Grains; Tropical zone; Estuaries; Geochemistry; Metal; Sensitivity resistance; Seasonal variation; Ecological abundance
• ISSN: 0272-7714; 1096-0015
• DOI: 10.1016/j.ecss.2009.08.020

The aim of this study is to understand the various sources and factors controlling the abundance and distribution of the metals through the analyses of selected metals (iron, manganese, chromium, copper, zinc and cobalt), sand, silt, clay, organic carbon and magnetic susceptibility of the surface sediments of Zuari estuary in three different seasons. Total suspended matter (TSM) concentration and salinity of near surface and bottom waters were also measured. The study undertaken for three seasons, based on 18 selected stations all along the estuary, indicated that the concentration of most of the metals were comparatively higher during pre-monsoon than in monsoon and post-monsoon seasons. Further, along the length of the estuary, high concentrations were observed at lower middle and lower estuary and also at few stations at the upstream end. Salinity, distribution of TSM, size of the sediment, organic matter, geomorphological setup, fresh water input from land and release of industrial waste within the estuary played a role in distribution and concentration of metals. Magnetic measurements indicated the dominance of haematite like minerals and helped in understanding the source and depositional processes.