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Over several decades, the mouth of the Mejerda River (northern Tunisia) has received large amounts of mining tailings mainly containing Pb, Zn and Ba. We have measured the concentrations of major and trace elements (Al, Ti, P, K, Mg, Na, Ca, S, Fe, Cl, V, Cr, Co, Ni, Cu, Zn, Ga, Br, Rb, Sr, Y, Zr, Nb, I, Ba and Pb) in three different fractions of 4...
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... data indicate an accumulation of total organic carbon close to the Mejerda River and Ghar El Melah Lagoon shores, where TOC exceeds 1%, mainly in the central part of the Gulf ( Figure 5). This zone presented a bathymetric variation area (Figure 4) which facilitated the accumulation process. ...
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... total organic carbon content in surface sediments of the Gulf of Tunis varied between 0.08% and 1.37 % (avg. 0.68%; Figure 5). Nitrogen was present off the Mejerda River and Ghar El Melah Lagoon, as well as in the central part of the Gulf (avg. ...
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... element distribution showed a relative accumulation of Zn, downstream of the Mejerda River, reaching a concentration of 398 µg g -1 for fine particles (<2 µm). The distribution of Pb was homogenous in the three fractions, mainly off Ghar el Melh lagoon, and little accumulation (68 µg g -1 ) was observed in the fine particles (<2 µm) at the distal end of the Mejerda River ( Figure 5, Table 3). The distribution of Cu showed a higher concentration (62 µg g -1 in average) in the fine fraction (<2 µm) when compared with coarser grain sizes (55 µg g -1 in the 2-20 µm fraction and 48 µg g -1 in the 20-63 µm fraction). ...
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... results showed a significant correlation between particle size and type and concentration of trace elements. Trace elements in different grain size fractions were enriched in Pb and Zn off the mouth of the Mejerda River ( Figure 5) compared with coastal zone of Sfax, Tunisia. For example, Gargouri et al. (2010) found a deficiency of Zn and Pb in the coastal zone of Sfax compared with Gulf of Tunis values. ...
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... Solution extraction blanks containing the solvent and all reagents used in an analysis, with the exception of the sample were also made. The ne fraction samples (< 63 µm) were digested according to the protocol proposed by Zaaboub et al. (2014) and modi ed by (Rajaram et al. 2020) which is a method involving hydro uoric acid (HF) and regal water (HCl: HNO 3 ; 3:1, v/v). An amount of about 100 mg of the ne fraction (< 63 µm) introduced into a Te on (savillex) bottle was slowly digested in 10 ml of regal water at 100°C overnight. ...
Surface sediments from the intertidal area of Côte d’Ivoire were sampled to investigate trace metals (Hg, Cd, Cr, Cu, Pb, Zn, and As) concentrations to illustrate their spatial distribution and ecological risk of pollution. The average total organic carbon content was 2.04 ± 0.01%. Except for Cr and Zn, the spatial distribution exhibited a similar pattern for TOC, Hg, Cd, Cu, Pb, and As. The average concentrations of trace metals were less than their corresponding UCC values, except for Cd and Cr. The pollution indices indicated that sediment quality in the studied area has been impacted by Cd and the Assinie and Bleron sites were the most contaminated. A few ecological risks were posed by Hg, Cd, Cr, and Cu, based on sediment quality guidelines (SQGs). The Pearson correlation showed a significant ( p < 0.05 ) correlation between As, Cd, Pb, Cr, and Hg, suggesting a common origin in sediments. Although this study presents the current status of littoral trace metals contamination level in sediments, further studies should integrate the statistical multivariate approach to determine the anthropogenic sources of the trace metals in the intertidal area of Côte d’Ivoire.
... They are generally located in geomorphologically protected water bodies, such as bays or estuaries, with low hydrodynamic conditions and restricted water exchange with the adjacent sea; they also frequently present lower oxygen levels in the water column, accumulating highly contaminated sediments [1]. As a result, many harbors are classified as critically contaminated spots, with low pollutant removal in the sediments resulting in high bioavailability and toxicity to the local trophic net [2,3]. ...
Citation: Delgado, J.d.F.; Amorim, R.M.; Lima, L.d.S.; Gaylarde, C.C.; Neto, J.A.B.; Pinto, S.C.d.S.; Gonçalves, B.F.d.S.; Fonseca, E.M.d. Negative Impacts of Trace Metal Contamination on the Macrobenthic Communities along the Santos Port Complex-Brazil. Eng 2023, 4, Abstract: Port sites represent one of the most impacted coastal areas; this impact is due to intensive anthropogenic pressures. In addition to the port complex itself, associated activities, such as indiscriminate disposal of pollutants, including trace metals, affect the local ecosystem. Macroinvertebrate benthic communities are one of the most effective bioindicators of environmental health because of their importance as a primary food source for many fish, birds, and mammals, as well as their influence on sediment stability and geochemical composition. This article evaluates the benthic macrofauna in the Santos Estuarine System (SES), the location of the Santos Port Complex (SPC), linking trace metal levels to differences in microbenthic community structure and pollutant bioavail-ability. The distribution of Cd, Ni, and Pb was directly related to organic matter deposits, while Cu and Zn appeared to result from port activities. The SES contained a poor benthic macroinvertebrate community, resulting from the contaminated muddy sediments. A significant negative correlation was found between the macrobenthic diversity and concentrations of Cu in the soluble phase; this implied the pollution-induced degradation of the macrobenthos in SES.
... Owing to the specificity of harbour environments characterized by poor water exchange, such areas are considered as sinks for the accumulation of pollutants, especially heavy metals, which are classified as harmful due to their persistence in the environment together with their toxicity and ability to be absorbed into the food chain [21,22]. ...
Harbours are one of the most disturbed coastal ecosystems due to intensive anthropogenic pressures. This study aimed for the first time to compare anthropogenic impacts in three harbours from the central coast of Tunisia (Mediterranean Sea) employing analysis of heavy metal contamination and ecological quality status (EcoQS). Sampling was carried out in spring 2019 in the fishing harbour of Teboulba, the marina of Monastir, and the commercial harbour of Sousse. The high levels of concentration in heavy metals and organic matter were closely related to the fine-grained fraction of the sediment in the fishing and commercial harbours. A total of 94 macrobenthic species, including five nonindigenous species, were identified belonging to six zoological groups. Multivariate analyses highlighted a strong influence of the harbour activity on the diversity of macrozoobenthic communities. Three benthic assemblages were identified according to their environmental characteristics such as sediment type, organic matter content, and heavy metal contamination. Benthic and biotic indices (H′, J′, AMBI, and BO2A) showed that the EcoQS varied from poor (commercial harbour) to good (marina), and was significantly influenced by harbour activity, organic matter, and heavy metal contamination of the sediment. The present work could be considered as providing important baseline data for the implementation of national environmental policies and management plans in the future.
... To compare sediment trace element composition among estuaries, the fine fraction (<10 μm) of sediment samples was obtained by particle separation by thoroughly mixing sediment with 1 L of deionized water in plastic measuring cylinders with decanting taps (Horowitz, 1991;Zaaboub et al., 2014). This is considered an appropriate size fraction to analyze for sediment geochemistry of Australian estuarine sediment (Laceby et al., 2017). ...
Trace element accumulation pathways are important in many ecological and toxicological studies on aquatic organisms, yet these pathways are often poorly understood. To study the influence of diet and environment on the trace element composition of species within estuarine food webs, we performed a community level assessment of 28 trace elements (including major and minor elements) in common fish and prawn taxa across four estuaries, and in fish, prawn, and other invertebrate taxa within a single estuary. Despite sediment substrates from the four estuaries having distinctly different geochemical compositions, food web samples showed no separation by estuary, but clear separation by taxa. Grouping of taxa by trace elements was related to feeding ecology, with pelagic taxa separated from benthic taxa, and mixed feeding by generalist taxa. Arsenic and selenium were more concentrated in benthic fish, while aluminium, barium, copper, iron, manganese, vanadium, and zinc were more concentrated in pelagic fish. Trophic level did not appear to influence trace element composition. Previous laboratory studies have shown that food sources influence trace element concentrations in marine taxa and this study confirms that this also occurs in natural food webs. These results improve our understanding of the dominant importance of diet and physiology in controlling the trace element composition of species within estuarine food webs.
... The Gulf of Tunis is among the most Mediterranean Sea's fragile areas and thus was the subject of several research studies aiming at investigating the quality of surface sediments (e.g., Rais, 1999;Added et al., 2003;Ennouri et al., 2010Ennouri et al., , 2015Zaaboub et al., 2014;Helali et al., 2016;Oueslati et al., 2017). These studies reported a substantial accumulation of metals in surface sediments collected from coastal areas; near the outlet of the two main rivers flowing into the gulf and in the bay of Tunis. ...
... c Ennouri et al. (2015). d Zaaboub et al. (2014). e Ennouri et al. (2010). ...
To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indices (Potential ecological risk index, Toxic unit and Mean effect-range median quotient) and comparison with sediment quality guidelines suggest that in addition to Mercury, Cr, Pb and Ni concentrations are detrimental to biota in both the offshore and areas near to the exchange points with the gulf. Moreover, in these areas the results from sequential extraction and individual contamination factor calculation pointed to the mobility and bioavailability of Cr, Pb and Ni.
... Due to the natural processes and the anthropogenic interventions, the coastline sediment balance is very sensitive to any environmental change (Zaaboub et al., 2014a;Brahim et al., 2015). Several previous studies (Zaaboub et al., 2014b;Ben Amor et al., 2019) have investigated the trace metals in the surface sediments of the Gulf of Tunis without focusing on the potential sources of these elements. In this work, in addition to the assessment of trace metals in marine sediments, we are interested to their inputs by Meliane River from the watershed to the sea. ...
The Meliane River, the second longest and most important river in Tunisia, is one of the major rivers that flow into the Gulf of Tunis. However, it is known by its significant discharges of urban and industrial activities that have seriously affected the quality of the aquatic ecosystem. The highest amounts of Cadmium (Cd), Copper (Cu), Lead (Pb), Zinc (Zn), Nickel (Ni), Chromium (Cr) and Manganese (Mn) in the surface sediments of the Meliane River indicate that the downstream part is the most polluted area. The chemical speciation shows that the majority of the trace metals are bound to a reducible fraction (Zn, Mn, Cr and Ni) and the Pb and Cu are bound to the oxidizable fraction. The Cd is linked to the exchangeable fraction, which indicates its high mobility and toxicity. Both the contamination and enrichment factors values of some trace metals are elevated in the downstream part of the Meliane River. The percentage of the risk assessment code in Cd is 59.8%, which presents a very high environmental risk. Therefore, the spatial distribution of trace elements in the surface sediments is characterized by its high concentration of metals in the downstream part of the Meliane River. These concentrations decrease as a function of change in the physicochemical parameters from the freshwater-saltwater mixing zone to marine stations.
... They stated that major contribution of strontium to the deep-sea sediments is due to carbonate shells of coccoliths, corals and foraminifera indicating mixed hydrogenous and biogenous origin. The average concentration of Sr obtained in the present study core 153.7 ppm is higher than those reported for the Bay of Bengal sediments (120 ppm), Godavari delta sediments (115 ppm), lower than the Nizampatnam Bay (189 ppm), middle Bengal fan sediments (189 ppm); average value of Indian river sediments (217 ppm) and also lower than theSr obtained for central Mediterransean sea (Noureddine et al., 2014;Sarin, 1979;Venkateswara, 2008;Subramanian, 1985). ...
... Reinson reported that the fine grained detrital mineral factors exhibit dominant control on the vanadium distribution (Reinson, 1975). Vanadium mainly occurs in the fine-grained terrigenous fraction that associates with aluminum silicates, iron oxides, and additionally with phosphate (Seralathan, 1987;Hartmann and Seralathan, 1986;Noureddine, et al., 2014). The concentration of vanadium in the present study found to vary in the range 196.7 to 59.9 ppm having an average value 120.7 ppm. ...
... The obtained average concentration (120.7 ppm) of V in the present study is lower than the core sediment of Nizampatnam Bay (163 ppm), the Godavari delta area (190 ppm), central Mediterransean Sea and equal to Bengal Fan sediments (124 ppm) average value (Venkateswara, 2008;Noureddine et al., 2014). It shows an agreement with the average deepsea clays 120 ppm and with the igneous rock average values127 ppm (Turekian and Wedephol, 1961;Chester and Aston, 1976). ...
The aim of the present work is to estimate the accumulation of various elements related to the core sediment belong to the Krishna-Godavari marginal area with a nuclear analytical technique. Hence, a 4.12 m long marine sediment gravity core was collected from near to Nizampatnam Bay that related to Bay of Bengal and by using particle induced X-ray emission (PIXE) elemental concentrations have been determined. The concentrations of major elements like Fe, Ca, K, Ti, Mn and minor (trace) elements such as Sr, Co, V, Zn, Ni, Cu, Rb, Sc and Cr have been evaluated with the obtained PIXE spectra. These values are interpreted based on the monsoonal runoff coming from the rivers causing to play an important role for bring lot of sedimentary material of the coastal waters to the Bay of Bengal. Further results are interpreted to understand biological and anthropogenic activities, chemical reactions etc during Holocene and Pleistocene periods.
... Sediment samples were separated from impurities such as wood, plastic, and others. Samples were then dried in an oven at 50 ̶ 60 °C to a constant weight [12]. Samples were put into an automatic sieve (sieve shaker) with mesh size No.12 to produce medium or medium-size sand sediments. ...
To elucidate the sources of Fe in Tiga Warna Beach, fine sediment can be monitored through their analysis with the BCR microwave optimized method using AAS. The accuracy and precision of the optimized BCR microwave method were analyzed for exploring of Fe concentrations detailed after XRF analysis. Assessment of contamination factors (CF) and geo-accumulation index values (Igeo) was evaluated in each fraction to establish the anthropogenic or natural sources. The results showed that the optimized microwave BCR method can be used for leaching Fe accurately (89.4%) with precision (RSD <30%). The explored of Fe in sediments tended to accumulate in easily oxidized and residual fractions. Assessment of Fe in sediment can be categorized in Tiga Warna Beach with low levels of Fe contents in blue water (CF: 1.00, Igeo: 0.23), red water (CF: 1.83, Igeo: 1.10), and green water (CF: 2.42, Igeo: 1.51) locations. We suggested the assessed sediment as the uncontaminated or natural Tiga Warna Beach sediment.
... In the finegrained near-shore sediments in Gulf of Gabes, where there is only limited urban discharge from land, Ayadi et al. (2014) found much lower values of TOC ranging between 19 500 and 27 000 mg/kg. Northwest of the Gulf of Tunis, where there is a limited anthropogenic discharge, Zaaboub et al. (2014) recorded in the fine-grained near-shore sediments, much lower values of TOC compared than those founded in this study, ranging between 800 and 13 700 mg/kg. Generally, the highest content of TOC was found in sediments with high clay and silt content and lowest Eh values. ...
... The coarser sediment discharge retained by the dam and dike constructions contributes to the evolution of the facies in the shallowest areas (surfer-swash zones) from sandy to very fine (Saidi 2013;Amrouni et al. 2014;Hzami et al. 2016). In sediments below a depth of 25 m, mineralogical studies show that clay and fine silt particles are predominant (75-95%) (Zaaboub et al. 2014). The summer wave storm affecting the Medjerda littoral cell is of low energy, although waves can reach heights of up to 4 m during storms (LCHF 1978;DGSAM 1995). ...
As coastal areas become increasingly vulnerable to climate change, the study of nearshore sediment textures along the littoral cell of the Medjerda delta in the Gulf of Tunis, southern Mediterranean coast can provide valuable information (i) on the origin (continental or marine) of the sediment, (ii) its transport direction, and (iii) constitutes an important tool in the assessment of coastal sensitivity. A total of 120 sediments samples underwent grain size analysis and statistic parameters have been calculated. These allowed the identification of five different Sedimentary Types (ST). Accordingly, using grain size indexes (i.e. Mz, SKI and Ku), Sediment Trend Analysis (STA) modeling tools were applied to define the seasonal sediment transport pathways throughout the nearshore of the Medjerda sedimentary cell. Results show that grain size distribution (GSD) and STA model pathways are determined by cross-shore geomorphology, location of the sediment-cell, seasonal incident wave and local terrestrial supply. The appearance in an atypical seabed location of the finer (Mo = 0.1 mm) and the coarser STs (Mo = 0.8 mm) can be indicative of human influence since the coarser particles are usually retained by dam structures. Moreover, the bimodality and the increased distribution of mud are also related to the seasonal incident wave winnowing of the historic deltaic plain submerged by the relative rise in sea level. The evolution of the sediment pattern towards a greater proportion of very fine grains indicates a deficit of sediment supply, particularly of the coarser grains, and demonstrates the coastal vulnerability of the Gulf of Tunis due to anthropic effects.
