Distribution of metals in Labeo coubie (Ruppel, 1832) from a National Park river in Nigeria

Abstract

This study assesses heavy metals distribution in body parts of Labeo coubie (African carp) from
River Oli, in Kainji Lake National Park as pollution index of the ecosystem. Fish parts samples (gills, muscles and
vertebra bone) were prepared and specifically analyzed for the levels of Pb, Cr, Zn, Cu, Fe and Cd using Atomic
absorption spectrophotometry. The concentration of metals in the samples at different concentrations ranged from
0.001±0.000 μg/g for Cd to 224.87±4.07 μg/g of Fe in the fish gill. There is significant (p<0.05) differences in the Pb,
Zn, Cu and Fe concentrations across the different fish parts with gills accumulated the highest levels metals while Cr
levels significantly (p<0.05) differed in the fish body parts and accumulated more in the muscles (10.75±0.15 μg/g).
The mean concentrations of metal elements in the fish parts had shown some distinguish connection in its distributions
with Pb and Cu; Gills > Muscles > Vertebra bones, Fe and Zinc; Gills > Vertebra bones > Muscles while Cr was
distributed in Muscles > Gill > Vertebra bones. However, it is revealed that Labeo coubie, a euryphagus fish probably
absorb these metals through ingestion of contaminated food or absorption by the gills and bioaccumulate in different
fish parts. It is therefore established that River Oli is contaminated with heavy metals as presence of these metals in
fish is an indication of its immediate environment.

Keywords: absorption, bioaccumulation, fish parts, heavy metals, pollution