Heavy metals contamination in fish and shrimp from coastal regions of Karachi, Pakistan

Abstract

In the present study, the heavy metals (Pb, Cu, Cd, Fe, Zn) concentration was determined by using atomic absorption spectrophotometer (AAS) in 5 species offish and 3 species of shrimp commonly taken by locals at the coastal regions of Karachi, Pakistan Concentrations of Cd and Pb studied in tissues of Mushka (Otolithes ruber, 0.120 and 1.018 μg/g wet weight) and Palaemon longirostris shrimp (2.457 and 0.480 μg/g wet weight) were found near to safe level for human consumption. Mullet, Tarli, Surmai, Dohtar fishes and Blacktiger shrimp were found contaminated by Cd and Pb but still within the limits fit for and human consumption. The distribution of trace metals detected in all fish and shrimp species followed the order of Zn >Pb> Fe>Cu> Cd and Cd> Fe > Zn> Cu>b, respectively. Metal concentration exhibited significant species variation and followed the order in fishes as Otolithes ruber> Liza vaigiensis>Sardinella albella >Scomberomorus guttatus>Pomadasys olivaecum and in shrimp as Palaemon longirostris>Penaeus monodon>Penaeus penicillatu.