Distribution, partitioning, bioaccumulation of trace elements in water, sediment and fish from sewage fed fish ponds in eastern Kolkata, India

Abstract

Concentrations of trace elements were measured in water (Cu, Zn, Fe, Pb, Mn, and Al), sediment (Cr, Cu, Mn, Pb, Ni, Al, Zn, Fe, and Co), and muscle tissue of nine selected fish species (Cu, Zn, Fe, and Mn) collected from eastern Kolkata (India) estuarine-sewage fed fish ponds. In water, trace elements existed in particulate phase (60–80%) with Fe as the predominant element followed by Al > Mn > Zn > Pb > Cu. The partitioning coefficients (Kd ) of the trace elements are low and fairly stable. The Pearson product moment correlation among the elements in the particulate and dissolved phase of the water column was calculated and most of the elements are correlated well (p ≤ 0.005). The trace element concentrations in sediments were in the following order: Al ≥ Fe > Mn > Zn > Cu > Ni > Cr > Pb > Co. Contamination factors (CFs) of trace elements in sediments were in the order of Pb ≥ Cu > Zn > Fe > Mn ≥ Ni ≥ Co > Al > Cr and Pollution Load Index ranges were 0.33–0.56. The CFs for Pb, Cu, and Zn are 0.92, 0.88, and 0.73, respectively, shows natural as well as anthropogenic inputs of these elements into the Kolkata sewage fed fish ponds. Accumulation of trace elements in muscle tissue of nine selected fish species were, Fe > Zn ≫ Cu > Mn Silver carp contained high Cu and Fe, American rohu contained high Zn concentration while Nylontica species contained high Mn concentration. Bio-concentration factor and bio-accumulation factor of elements, (Fe, Zn, Cu, and Mn) in fish, showed positive and negative accumulation factors when calculated against elements in the dissolved and suspended particulate matter phase of water, respectively. Iron (Fe), Mn, and Zn concentration in fish tissue were greater than WHO/FAO certified values; therefore, regular monitoring of trace elements is warranted for fish tissue collected from these estuarine-sewage fed fish ponds.