African Journal of Food Science and Technology (ISSN: 2141-5455) Vol. 6(4) pp. 098-107, July, 2015
Available online @http://www.interesjournals.org/AJFST
DOI: http:/dx.doi.org/10.14303/ajfst.2015.041
Copyright ©2015 International Research Journals
Full Length Research Paper
Detection of heavy metals bio-accumulation in
scombrids for the determination of possible health
hazard
Vishwakalyan Bhoyroo, Naajiyah Soobtratty and Bhanooduth Lalljee
Department of Agricultural And Food Sciences Faculty of Agriculture University of Mauritius Reduit Mauritius
Corresponding email: v.bhoyroo@uom.ac.mu
ABSTRACT
Concentrations of trace elements zinc, copper, nickel, chromium and heavy metals lead, mercury,
cadmium and arsenic were detected in the muscle tissues of four commercially edible fishes belonging
to the scombridae and related families including yellow fin tuna (Thunnus albacares), Dogtooth tuna
(Gymnosarda unicolor), Marlin (Makaira mazara) and the dolphin fish (Coryphaena hippuru) in the EEZ
(Exclusive Economic Zone) of Mauritius. The concentrations were within the range 1.34-10.03, 0.0-1.42,
0.23-0.89, 0.0-2.43, 0.0, 3.60-5.44, 0.03-0.13 and 0.03-0.07 mg/kg wet weight respectively for summer and
winter seasons. Inter-species variations with respect to elemental accumulations were not significantly
different as compared to seasonal variations for the accumulation of chromium, zinc and lead. Marlin
and Dorado caught during the summer season exceeded the authorised level of chromium in muscle
tissues according to international standards. A survey carried out among fish consumers in Mauritius
revealed that 80 % of the respondents were ignorant about heavy metal bio-accumulation.
Keywords : Mauritius, muscle tissues, heavy metals, yellow fin tuna, Dogtooth tuna, Marlin, Dorado
INTRODUCTION
Heavy metals pollution in the marine ecosystems is a
result of anthropogenic activities such as mining,
shipping, agriculture and domestics (Haynes & Johnson,
2000; Islam & Tanaka, 2004). Humans as well as aquatic
organisms are under the threat of a rise in heavy metals
concentration in the marine environment (Uluturhan et al.,
2007; Naji et al., 2010; Bashir et al., 2013). In the last
few decades, fishes have been the subject of various
studies around the world due to their ability to bio-
accumulate heavy metals (Elnabris et al., 2013). In an
attempt to reduce possible human health hazards,
commercially edible fish species are favoured for studies
since the diet is the main route of human exposure to
heavy metals (Türkmen et al., 2005; Tepe et al., 2008;
Raja et al., 2009; Alina et al., 2011; Kumar et al., 2012).
Heavy metals that are classified as harmful toxic
substances are mercury, arsenic, lead and Cadmium
among others. Mercury is considered as one of the most
dangerous toxic heavy metal that can have adverse
effects on human health. Lead and arsenic affects the
reproductive system of women, by displaying toxicity
towards the growing foetus (Goeringa et al., 2010) while
cadmium builds up in the placenta (Berlin et al., 1992;
Moberg et al., 1992; Jarup et al., 1998). Trace elements
such as Zinc, Copper, Nickel and Chromium are present
in low amount and are important in the human body
system (Fraga et al., 2005). However, if present in
excess, they acquire toxic properties depending on the
absorption, concentration and persistence at their action
points (Shanker, 2008)
In the island of Mauritius with an Exclusive Economic
Zone (EEZ) of around 1.9 million km, the previous
Minister of Fisheries, Nicolas Von-Mally predicted a
bloom in the Seafood Hub with investments ranging from
Rs 30 billion to Rs 40 million ( Business Mega, 2014 ).
Local sea food consumption in Mauritius per capita is