International Journal of Marine Science, 2017, Vol.7, No.9, 76-87
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2015a; 2015b) and purge in fishes where the synthesis of metallothionein induced by metals occur (Boudou and
Ribeyre, 1989). Other organ that may be regarded for assay is the gill, which is in steady contact with the
surrounding water and the metals contained therein (Ahmed and Bat, 2015e; Ahmed et al., 2015a; 2015c). Fish is
a major source of protein and gain for people living in the south-eastern Asia. However, detrimental substances
such as metals released by anthropogenic activities have contaminated the marine coastal environment. For
example, the Straits of Malacca, a momentous fishing place (Eng et al., 1989) is badly polluted by international
shipping activity, intense industrialization and urbanization, and oil spills (Eng et al., 1989; Abdullah et al., 1999).
The main aim of the current study to determine Fe, Mn, Cu and Zn concentrations in
Katsuwonus pelamis
collected from Karachi fish harbour (Figure 1).
Figure 1 Map of Karachi coast
1 Materials and Methods
K. pelamis
specimens of similar sizes were collected seasonally between August 2006 and December 2011. After
biometric measurements, specimens were dissected using steel scissors and scalpels to take about 5 g edible
muscles, entire organs (liver, kidney and gonads) and two rakers of gills. They were cleaned with deionized water
and weighed (modified from UNEP, 1984; 1985; Tuzen, 2003; Karadede et al., 2004; Papagiannis et al., 2004).
The specimens were crushed and calcinated at 500
o
C for three hours til they turned to white or grey. Then they
were prepared with respect to the procedure of Gutierrez et al. (1978). The cinders were melted in 10 ml (HCl) in
beakers and which the residues were filtered with Whatman filter paper and after were diluted to 25 ml distilled
water with 1 N HNO
3
. The equipment AAS Perkin Elmer, model AAnalyst 700, USA, with background
adjustment and acetylene as fuel were initiated and presented programme win lab 32 software. The absorption
wavelengths (nm) for Cu, Zn, Fe and Mn were 324.7, 213.9, 248.3 and 279.5, respectively. The detection limits of
Cu, Zn, Fe and Mn were 0.23, 0.50, 0.45 and 0.58 ppb, respectively. At least three standards from 1000 ppm stock
solution to 2, 4 and 6 ppm were made. The equipment together with the referred standards were calibrated. The
specimens severally were aspirated to determine Cu, Zn, Fe and Mn levels. A one-way analysis of variance
(ANOVA) in which the within sample variances and between the sample variances were employed to regard the
initial step interactions between the organs, year and seasons (Snedecor and Cochran, 1967). The Bonferroni test
was applied for correction to set agains the problem of multiple comparisons. All values were expressed as µg
metal g dry wt.
