International Journal of Marine Science 2016, Vol.6, No.26, 1-13
4
each station were used for metal analysis; usually one individual of large animals represented a replicate, but
composite samples from smaller size organisms were used for each replicate. Wet digested samples were filtered,
diluted with deionized distilled water and analyzed for Cd, Pb Cu and Zn using Flame Atomic Absorption
Spectrophotometer (FAAS Perkin Elmer model AAnalyst 100). The obtained results were expressed in µg/g wet
weight.
De-ionized water was used to prepare all solutions and blanks. All vessels and glassware were soaked in 10%
nitric acid overnight and later rinsed with distilled water. Precision of the methods was verified by analysis of
replicate measurements for the studied metals in the sample of sediments and marine organism. The obtained
results showed precision of 7.5 – 12.3 and 4.1 – 9.8 %, respectively, for all studied metals.
3.4 Statistical Analysis
Heavy metal data in sediments and bivalve species were subjected to analysis of variance “ANOVA” to
investigate the differences between stations and seasons concentration (significant values, p≤0.05 for all analysis).
Duncan's multiple range test was used to further determine the position of the variance in significant results.
Statistical analysis was carried out using Statistica X software packages for windows and Origin Pro 9.
4 Results and Discussion
4.1 Heavy metals in sediments
Table (1) show the values of Cd, Pb, Cu and Zn in sediment samples collected during summer and winter from
different investigated stations along the western side of the northern part of the Gulf of Suez. It can be observed
that, at all sampled stations, the concentrations of Zn represent the highest value in the present study area followed
by Pb(II) and Cu(II) ions, while Cd(II) ion was the lowest one. As well as Cd(II), Pb(II) and Cu(II) ions s howed
the highest mean values during summer season; in contrast, Zn(II) was found in winter season (Fig. 2). During
summer, heavy metals concentration in sediments from Gulf of Chabahar, Oman Sea were increased markedly
(Bazzi, 2014); and he suggested that increasing of nutrient availability due to upwelling during summer season
enhanced phytoplankton growth followed by increasing of suspended organic matter which should be involved of
heavy metals enrichment of sediments. Statistically, using ANOVA analysis, only Pb(II) ion revealed significant
variation between the two studied seasons (p = 0.0426), while the other metals showed insignificant variations.
Abouhend and El-Moselhy (2015) investigated seasonal variations of heavy metals in the sediments from northern
Red Sea, and recorded small temporal range of metal levels with high concentrations during winter and autumn
seasons.
Figure (2): Mean concentrations of heavy metals (µg/g) in sediments of the northern part of the Gulf of Suez.
