Abstract
In this study, we have evaluated the concentrations of heavy metals (Cu, Zn, Cd, and Pb) in 24 flatfish species (Order: Pleuronectiformes) collected from the Gulf of Mannar Biosphere Reserve, Tamil Nadu, India. All four metals were recorded in all flatfishes except for lead which was below detection limits in nine species. The order of metal concentrations in the flatfishes is Zn > Cu > Pb > Cd. Bioaccumulation factor (BAF), principal component analysis (PCA), and hierarchical cluster analysis (HCA) were carried out. BAFs of different metals follow the order Cd > Zn > Cu > Pb. A firm positive correlation was observed between the metal concentrations among the tissues of different flatfishes. PCA and HCA indicate that the metals originated mostly from the manmade activities. These heavy metals sink to the sediments of the sea floor and are bioaccumulated in the bottom-dwelling flatfishes. Continued surveillance of metal concentrations in sediments and flatfishes should be conducted to remediate the metal pollution effectively.
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•Metal contaminants in flatfishes (Order: Pleuronectiformes) were evaluated.•The order of metal concentrations in the flatfishes is reported as Zn>Cu>Pb>Cd.•The bioaccumulation factor for different metals is in the order Cd>Zn>Cu>Pb.•Strong positive correlation was observed amidst metal concentrations in flatfishes.•PCA & HCA state that metal pollution (Pb & Cd) is mainly due to manmade activities.