Spatial distribution and environmental assessment of heavy metals in the surface sediments of Kongsfjorden, Svalbard

Abstract

Spatial distribution and environmental assessment of heavy metals of the surface sediment samples collected from the Kongsfjorden system, Svalbard during summer months of 2011, 2012 and 2013 were studied using grain size, organic carbon and metal concentrations (Mn, Cr, Zn, Co, Cu, Ti and Pb). The Inner fjord was blanketed by clayrich sediments while clayey silt or silty clay was found in the Outer fjord. High sedimentation rate and the water column turbulence resulted in the poor preservation of the organic matter in the Inner fjord while high concentration of TOC in the Outer fjord sediments indicated high primary productivity. Further, in the Outer fjord, the concentration of metals like Mn, Cr, Zn, Co, Cu and Pb were found to be higher near the mouth of the fjord while the lowest concentrations were at its distal end. The Inner fjord was also characterized by a concurrent enrichment of these heavy metals near the glacier outlets with the lowest values occurring near the shallow sill separating it from the Outer fjord. The significant positive correlation of all the heavy metals except Pb in the outer and inner part of the fjord, among themselves and also with Ti corroborated their terrigenous source possibly derived from the rocks present in the catchment area through the glacier melt waters. While, uniform negative correlation exhibited by Pb with all the other elements may point to its source from elsewhere, indicating its source to be anthropogenic.