Comparative assessment of heavy metals concentrations in the muscles, gills and guts of croaker, Pseudotolithus senegalensis from coastal waters of Nigeria and South America

Ayo-Olalusi, C. I. , Omoboye, H. Y. and Ozor, P. A.

Keywords: Heavy metals, Pseudotolithus senegalensis, tissues, coastal waters, health risk
Published in Volume 28
download
Abstract:

Heavy metals pollution of aquatic ecosystems is a major environmental challenge because of its adverse effect on aquatic organisms and human health. This study investigated heavy metals accumulation in Pseudotolithus senegalensis obtained from Nigerian waters and imported from South America. Heavy metals concentrations were determined using Atomic Absorption Spectrophotometry. Zinc, Fe, Cu, Pb, Mn and Cr values were 1.49-11.31μg/g, 3.70-43.52μg/g, 0.6-2.72μg/g, 0.19-2.09μg/g, 0.02-4.47μg/g and 0.83-6.01μg/g, respectively. In the American samples, Zn and Fe were highest in the gut (11.31±0.387μg/g) while Fe was highest in the gills (22.26±0.014μg/g) of Nigerian specimens. Muscle tissues consistently had the lowest Zn and Fe concentrations in both groups. Copper and Cd were not detected in the muscles of the South American samples whereas Cd and Cr were absent in the gills and gut, respectively. Cluster analysis grouped Zn and Fe together whereas Cu, Cr, Cd, Pb and Mn formed a separate cluster. Principal Component Analysis identified two principal components that accounted for 98.89% of the total variance. Overall, gills and guts accumulated higher concentrations of heavy metals than muscles. Heavy metals levels in the Nigerian samples were within WHO limits whereas elevated Pb concentration in the South American samples may pose health risk to consumers.