International Journal of Marine Science, 2017, Vol.7, No.23, 214-228
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1.3 Sediment quality guidelines and Ecological Risk indices
Biological adverse effects were evaluated by comparing levels of the measured heavy metals with the numerical
sediment quality guidelines (SQG’s) proposed by Persuad et al. (1992). Two levels of risk were estimated; the
lowest effect level (LEL) and the sever effect level (SEL). The contamination status was assessed by comparing
the results of present study with available data given in previous literatures for leachable heavy metals in
sediments from various ports worldwide.
Several indices have been applied to assess the ecological risk of heavy metals in various aquatic environments
(Fujita et al., 2014) including; metal pollution load index (MPI) (Tomlinson et al. 1980), enrichment factor (EF)
(Salomons and Förstner, 1984), and the geo-chemical index (Igeo) (Müller, 1979). The interpretation of these
indices is depending on the comparison with a background levels. Rubio et al. (2000) have concluded that the use
of regional background values gives more appropriate results than the global background values, consequently the
mean results of Hanna (1992) for the sediments collected from the Red Sea during 1943 were used to calculate the
background values.
1.4 Statistical analysis
All statistics were performed using Statistica 10 and Wingraph Prism 7. One-way analysis of variance (ANOVA)
was applied to test significant variation in metal distribution between sites, and comparing levels of metals
between different fractions. To explore potential association between heavy metals and relationship among
variables, Pearson's correlation matrix and principal component analysis (PCA) were used.
2 Results and Discussions
2.1 Sediments characteristics
It has been reported that many characteristics of the marine sediments such as texture, organic matter and
carbonate content may influence the distribution of metals in sediments (Chen et al., 2007). The granulometry of
marine sediments at the different ports is illustrated in Figure 2. It can be noticed that the texture of all studied
stations was sandy. At Hurghada, the total of the finest fractions (Ø3, Ø4 and Ø5) was varied between 36.26% in
fishing port and 83.47% in front of passenger port; at Safaga, the fine fractions percentage was fluctuated between
46.32% in passenger wharf and 73.17% in the marine area off bauxite wharf with significant for Ø4; meanwhile at
the old port of Qusier, these percentage was varied from 59.83% to 64.69% with nearly equal occurrences for Ø3
and Ø4. The recorded high percentages of the fine fractions Ø3, Ø4 and Ø5 at the different ports indicating to
different sources of depositions mostly from the maritime activities, terrestrial runoff, phosphate shipments and
the nearby land based activities. Dar et al. (2016b) found the average percentages of finest sediments (Ø3, Ø4 and
Ø5) between 24.21% and 88.88 % with strong occurrence for Ø4 at Hurghada, and from 37.47% to 48.14% at
Safaga with strong occurrence for Ø3. They indicated that the high occurrence of fine sediments at Hurghada and
Safaga to the deposition under calm conditions due to the natural protections by the shallow coral terraces and the
frontal islands. Madkour and Dar (2007) reported that Ø4 has significant occurrence at the tidal flat area off
Hurghada Harbour. Mansour et al. (2013) attributed the high fine sediment contents in front of Hurghada to the
terrigenous inputs, landfilling and dredging operations.
2.2 Geochemical characteristics
2.2.1 Carbonates and total organic matter (TOM)
Table 1 shows the measured carbonate and total organic matter (TOM) percentages at the different stations. The
studied stations at Hurghada ports recorded the highest percentages of carbonates which was varied between 51.62
and 76.65% indicating that the biogenic source materials constituted significant portion of the sea sediments;
Safaga wharfs recorded significant variations in the carbonate percentages between less than 10% at grains and
passenger wharfs and 59.52% at quartz and orthoclase wharf; while the carbonate percentage was less than 50% at
the old port of Qusier. These data illustrated that the biological productions in the marine area off Hurghada and
Qusier have strong contribution in the high carbonate percentage; while the effects of maritime activities and
terrestrial runoff of terrigenous materials were the main reasons in carbonate percentage declining at Safaga ports.
Significant variations were observed in TOM contents at Hurghada and safaga ports due to the local effects of the
