Heavy metal concentrations in tissues of major carp and exotic carp from Bhagwanpur fish pond, India

Abstract

Aquatic ecosystem pollution by heavy metals is a worldwide concern. Heavy metals have the ability to bioaccumulate in aquatic organisms, particularly fish, which is a source of livelihood for humans. Between March 2012 and February 2014, we assessed heavy metal (Cu, Cr, Pb, Ni, Zn and Cd) contamination in two food fish species (Labeo rohita and Hypophthalmichthys molitrix) selected from Bhagwanpur fish pond in Roorkee, Haridwar, India. After acid digestion, the dried samples of fish tissues were analyzed for heavy metal concentrations by using atomic absorption spectrophotometery. Data obtained was analyzed using two way analysis of variance and Pearson’s correlation coefficient. The mean absorption of metals in different organs of L. rohita and H. molitrix ranged from 5.754±2.591-56.851±12.569 μg g -1 dry weight and from 5.455±3.651-53.625±11.432 μg g -1 dry weight, respectively. Heavy metal absorption was the highest in gill and liver tissues and the lowest in muscle tissues. Among all metals, Zn had the highest concentration in all the fish tissues. Statistical analysis revealed a significant variation (p<0.05) in heavy metal concentrations in the fish tissues during different seasons. The highest concentrations of heavy metals were found in the summer and the lowest in the spring. The concentrations of most of the studied heavy metals in the fish muscle (the edible part), liver, gill and scale tissues were higher than the permissible limits proposed by the World Health Organization, Food and Agriculture Organization and Ministry of Agriculture, Fisheries and Food.