TITLE:
Bioaccumulation of Zn in Muscle and Brain Tissues of the African Catfish—Clarias gariepinus
AUTHORS:
Amanna Chibuike Esinulo, Iloegbunam Alfred Kelle, Dike Henry Ogbuagu
KEYWORDS:
African Catfish, Heavy Metals, Tissue Accumulation, Delta State, Local Delicacy
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.5,
May
6,
2016
ABSTRACT: Increasing
rate of consumption of the common African catfish, Clarias gariepinus, a popular delicacy in Delta State, Nigeria has raised
worries about the safety of health of consumers in the face of perceived rising
input of recalcitrant pollutants such as the heavy metals in aquatic habitats. This
research investigated the presence and levels of Zn in muscle and brain tissues
of C. gariepinus sourced from selected
markets in Delta State. Replicate adult fish samples were obtained from seven market
locations in Oleh, Asaba, Ekpan, Ogwashi-Ukwu, Okere, Abraka and Ughelli towns,
labeled and taken to the laboratory in iced coolers. The presence and levels of
the heavy metal were determined spectrophotometrically. Concentrations ranged from
0.015 - 0.19 (0.09 ± 0.02) mg/kg d.w. in muscle and 0.035 - 0.36 (0.16 ± 0.03) mg/kg
d.w. in brain tissues, even as accumulation levels differed significantly (t = 0.005)
between the tissues at p (100.97) > Fcrit(4.02)] at the 95% confidence limit; with least accumulation
of 0.03 (±0.01) mg/kg d.w. recorded in fish samples obtained from Ughelli and maximum
accumulation of 0.28 (±0.07) mg/kg d.w. recorded in those obtained from Oleh locations.
However, levels were below the Food and Agricultural Organization and World Health
Organization acceptable limits for Zn in edible fish. Results revealed that lipophilic
brain tissues accumulated more heavy metal than muscle tissues. Since accumulation
levels were low, they do not currently constitute public health risks to consumers
in Delta State.