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Particulate metals contamination in the Kishon River estuary, Israel
Abstract
Suspended particulate matter (SPM) collected along the axis of the Kishon River, its estuary and Haifa Bay were analysed for trace metal concentrations together with measurements of water density, pH and dissolved oxygen. The concentrations of particulate Cd, Zn and Cu generally increased from the upper Kishon system (upstream from Tzipori-Kishon Junction) downstream and decreased from the Kishon Harbour seaward, while particulate Al concentrations decreased downstream and towards the open sea. Enrichment of Cd, Zn and Cu was found at Haifa Bay compared to the upper Kishon system. The axial profile of Mn concentrations indicated reduction of Mn at the anoxic and low pH zone of the lower river system and precipitation of Mnoxides at the estuary in response to the increase in pH and dissolved oxygen concentrations. Although Fe concentrations showed similar behavior to that of Al, the higher ratios at the estuary are probably due to precipitation of Fe-oxides onto pre-existing particles. This spatial non-conservative behavior of metals is presumably due to the: 1. mixing between polluted river-borne particles and material of drainage basin and coastal origin; 2. changes of the distribution coefficient of metals between the particulate and solution phases (Kd) with variations of salinity, pH and SPM concentrations; and 3. physical settling and currents. Short-term, tidal cycle measurements undertaken at the lower Kishon system (Julius Simon Bridge) indicated a high contribution of resuspended sediments to the SPM amounts due to the high tidal energy. It is hypothesized that the latter is the main mechanism by which SPM, which settles in the estuary, is transported landward creating a turbidity maximum zone between the Julius Simon and Histadrut bridges, i.e. about 3 km upstream from the estuary. It is proposed that the upper estuary zone acts as a purging system through which a low flux of SPM, enriched by organic and trace metal content, is transported seaward and from which a high flux of SPM is returned landward due to tidal stress.
... The Qishon River is the second largest river among the coastal rivers of Israel and also regarded as the most polluted river system in Israel (Herut et al., 2000;Herut and Kress, 1997). In general, pH is relatively constant, fluctuating between 9.1 and 7.5 down the river channel corresponding to the regional norm for carbonate provinces (Meybeck and Helmer, 1989). ...
... The river drains an area of approximately 1100 km 2 and flows through agricultural, domestic, and industrial districts before joining the Mediterranean Sea near the city of Haifa (Fig. 18). The Qishon's water is contaminated by agricultural runoff, various types of industrial effluents, and domestic sewage (Herut and Kress, 1997); by heavy metals and a mixture of organic materials (Richter et al., 2003;Herut et al., 1994;Krumgalz, 1993) including polycyclic aromatic hydrocarbons (PAHs), alkylated benzenes, halogenated alkanes, and chlorinated aromatic organic compounds; and some radionucleotides. As a result, the lower part of the Qishon River has been denuded for years of its multicellular life forms (Richter et al. 2003). ...
In an analysis of algal diversity we revealed different types of freshwater habitats in
Eurasia using statistics from gradients of altitude, latitude, and ecological regions.
Climatic impact over the altitude gradient was studied in the Caucasian region and
Israel. Species diversity increases with increasing altitude. Winter air temperature is
a regulating factor. The differentiation of endemic species over altitude shows the
impact of aridization through the Holocene up to the recent warming in Israel. The
impact on regional environmental differences was studied in polluted rivers of
Eurasia. Algal diversity is more sensitive to man-made pollution in the silicate
province, which is more tolerant to the same organic pollutants in the carbonate
province. A comparison of algal diversity in arctic and arid zone lakes shows that
communities are sensitive to climate warming and associated changes of salinity
also historically influence the algal diversity of the lakes. The hydrology and
anthropogenic loads administer the main impact on the river ecosystems in Israel,
while temperature conditions strongly modulate species richness from north to
south. Pollution and salinity sensitive communities fall under high risk of extinction
with ongoing climate change.
... Moreover, metal pollution may also result from past mining or smelting activities (Affholder et al., 2013;Frau and Ardau, 2003;Olías et al., 2004). In the countries of the Southern part of the Mediterranean basin, industrial effluents are most of the time discharged into rivers without any treatment (Giorgetti et al., 2011;Milovanovic, 2007) resulting in rivers highly contaminated with metals (Herut and Kress, 1997). Nevertheless, far fewer studies assessing metal pollution in rivers have been conducted in these countries in which many industrial activities are responsible of metal releases, in particular tannery and textile industries (Giorgetti et al., 2011;Koukal et al., 2004), fertilizer plants (Herut and Kress, 1997) and uncontrolled landfills (Marzougui and Ben Mammou, 2006). ...
... In the countries of the Southern part of the Mediterranean basin, industrial effluents are most of the time discharged into rivers without any treatment (Giorgetti et al., 2011;Milovanovic, 2007) resulting in rivers highly contaminated with metals (Herut and Kress, 1997). Nevertheless, far fewer studies assessing metal pollution in rivers have been conducted in these countries in which many industrial activities are responsible of metal releases, in particular tannery and textile industries (Giorgetti et al., 2011;Koukal et al., 2004), fertilizer plants (Herut and Kress, 1997) and uncontrolled landfills (Marzougui and Ben Mammou, 2006). ...
... The levels of pollution at the river estuaries along the Mediterranean coast of Israel are monitored and reported by the national marine environmental monitoring program (Herut et al., 2011). In several cases, as along the Mediterranean coast of Israel, the bottom bathymetry of the lower parts of the coastal streams lies below sea level, which enables the penetration of seawater and the formation of highly stratified estuaries up to a few kilometers inland (Herut and Kress, 1997). Despite the abundance of such small, stratified estuaries, their role in regulating the delivery of dissolved inorganic nitrogen (DIN), including nitrate (NO À 3 ), nitrite (NO À 2 ) and ammonium (NH þ 4 ) to the coastal area, especially in sensitive oligotrophic areas such as the Levantine basin, has not yet been thoroughly assessed. ...
... In the past high loads of anthropogenic heavy metals (Herut and Kress, 1997;Herut et al., 1999), nutrients (Kress and Herut, 1998) and organic matter (Cohen et al., 1993) were introduced to the Qishon estuary mainly by industrial effluents. However, since 2002, a dramatic decrease in heavy metals (approximately 2 orders of magnitude) and organic matter has been recorded, probably due to the introduction of treatment facilities at the industrial sites (Herut et al., 2011). ...
... The levels of pollution at the river estuaries along the Mediterranean coast of Israel are monitored and reported by the national marine environmental monitoring program (Herut et al., 2011). In several cases, as along the Mediterranean coast of Israel, the bottom bathymetry of the lower parts of the coastal streams lies below sea level, which enables the penetration of seawater and the formation of highly stratified estuaries up to a few kilometers inland (Herut and Kress, 1997). Despite the abundance of such small, stratified estuaries, their role in regulating the delivery of dissolved inorganic nitrogen (DIN), including nitrate (NO À 3 ), nitrite (NO À 2 ) and ammonium (NH þ 4 ) to the coastal area, especially in sensitive oligotrophic areas such as the Levantine basin, has not yet been thoroughly assessed. ...
... In the past high loads of anthropogenic heavy metals (Herut and Kress, 1997;Herut et al., 1999), nutrients (Kress and Herut, 1998) and organic matter (Cohen et al., 1993) were introduced to the Qishon estuary mainly by industrial effluents. However, since 2002, a dramatic decrease in heavy metals (approximately 2 orders of magnitude) and organic matter has been recorded, probably due to the introduction of treatment facilities at the industrial sites (Herut et al., 2011). ...
... Within the study area, a specific site was used as a deep-water (1500 m) disposal site for gypsum wastes from a single source (Hornung et al., 1993) and for dumping dredged sediments from ports deepening and enlarging Haifa port. The last is located at the contaminated Kishon River outlet to the SEMS (Herut and Kress, 1997). ...
... Along the Israeli Mediterranean shoreline at the SE Mediterranean Sea, the bathymetry of the lower parts of several coastal streams enables the penetration of seawater and the formation of ecologically unique highly stratified small-size estuaries up to a few kilometers inland [13][14][15][16][17][18]. These small estuarine water systems are exposed to severe anthropogenic pressures and low natural water flow, holding high nutrient contamination and low water quality conditions, and may induce HABs [19,20]. ...
Nutrient pollution may negatively affect the water quality and ecological status of rivers and estuaries worldwide, specifically in stratified and small inland estuaries. We present a long-term, two-decade data set of dissolved inorganic nutrient concentrations, chlorophyll-a (chl-a), dissolved oxygen (DO), and potentially toxic algal cell concentrations at the Kishon River estuary (Israel) as a case study for assessing nutrient ecological thresholds in such type of estuaries, prevalent along the Mediterranean coast of Israel. In-situ measurements and water samples were collected at 3 permanent stations at the lower part of the estuary every March and October/November in 40 campaigns over the years 2002 to 2021. In spite of an improvement in nutrient loads and concentrations as recorded over the last 2 decades, the nutrient and chl-a levels at the Kishon estuary surface water represent mostly a ‘bad’ or ‘moderate’ ecological state, considering the recommended thresholds discussed in this study. It is suggested to develop a combined suite of nutrient and biological variables for assessing Good Environmental Status (GES), considering the relatively high residence time of such small, low-flow estuarine water bodies.
... First, trace element in the environment will depend on trace element inputs, either naturally or from anthropogenic activities, through runoffs, rivers and estuaries and even sewage pipes (Herut and Kress 1997). For example, both Cd and Hg are naturally present in very low concentrations in seawater, originating from volcanic activity for example, while anthropogenic activities, including industrial processes, mining activities and even burning of fossil fuels, contributed to increase their concentrations in seawater Bernhoft 2013). ...
Food security, that is guarantying food supply and quality while sustainably managing
resources, is closely linked to knowing the biology and ecology of consumed species.
In a context of global changes that are threatening seafood safety, it is thus necessary
to establish baselines on marine ecosystem functioning, as well as nutrient availability
and contamination occurrence in seafood. This is all the more important in Small Island
Developing States (SIDS), where populations rely on marine resources for their
subsistence, and where capture fisheries resources are the main sources of proteins
and micronutrients (i.e. essential trace elements) in local populations’ diet. In spite of
the importance of tropical systems in ensuring food security, they remain largely
understudied compared to polar and temperate systems.
This thesis thus aims to better understand the functioning of tropical marine systems,
and to establish a baseline on micronutrient availability and metal(loid) contamination
in a wide diversity of capture fisheries resources from the Seychelles (Western Indian
Ocean), a tropical SIDS. By investigating trace element concentration patterns at the
inter- and intraspecific levels, it was possible to identify intrinsic and extrinsic factors
influencing trace element bioaccumulation in tropical capture fisheries resources. We
thus highlighted the importance of considering different scales (individual, species, and ecosystem) to better understand essential trace element availability and nonessential trace element occurrence in seafood.
... Thus, we hypothesize that the associations between copepods and microbes are particularly important in environments depleted in nutrients. Warming, pollution, and coastal development are rapidly increasing in the IMS (Amir, 2017;Herut & Kress, 1997;Ozer et al., 2017;van der Hal et al., 2017), which might also alter the interactions between copepods and their associated microbiota. ...
Copepods provide a rich organic microenvironment allowing the settlement and proliferation of microorganisms, forming dynamic microbial hotspots in the oceans. Such symbiotic associations in the plankton were previously hypothesized to be especially developed in warm oligotrophic seas, as they may serve as alternative sources of nutrients in biologically poor waters. Aiming to better understand how copepod micro-biomes are shaped in an oligotrophic sea, we characterized microbiota associated with three dominant coastal epipelagic copepod species in the ultra-oligotrophic Eastern Mediterranean Sea using amplicon sequencing of the 16S rRNA gene. Our results show that copepod-associated microbial communities were host-specific rather than determined by seasonal environmental changes. In the filter-feeding copepod with a tendency to herbivory, Temora stylifera, microbial diversity was low and relatively stable throughout the year. In contrast, omnivorous copepods, the ambush-feeding Oithona nana, and the mixed-feeding Centropages ponticus harbored more diverse mi-crobiomes dominated by transient taxa. We suggest that filter-feeding strategy and narrow food spectrum can limit copepod-microbe interactions, while the ambush and mixed feeding strategies combined with omnivory confer higher microbial diversity. Filter feeders may reduce the recruitment of opportunistic microbes by maintaining high fidelity associations, as indicated by the large number of core taxa in T. stylif-era. We underline the importance of the copepod-microbe associations in nutrient-impoverished ecosystems, based on predicted enrichment of nitrogen metabolism in the core microbiome, mostly during summer when the shallow coastal waters are nitrogen-depleted. K E Y W O R D S core microbiome, host-specificity, microbiota, oligotrophy, zooplankton traits
... Along the Israeli Mediterranean shoreline at the SE Mediterranean Sea, the bathymetry of the lower parts of several coastal streams enables the penetration of seawater and the formation of ecologically unique highly stratified small-size estuaries up to a few kilometers inland [13][14][15][16][17][18]. These small estuarine water systems are exposed to severe anthropogenic pressures and low natural water flow, holding high nutrient contamination and low water quality conditions, and may induce HABs [19,20]. ...
Seaweeds may contain significant amounts of essential proteins, carbohydrates, and minerals, offering an alternative, sustainable, healthy food source from the sea. However, there are yet challenges impending their full exploitation. Our study presents an innovative, two-step aquaculture approach integrating seaweeds and finfish, dedicated to enrich seaweeds with nutritional compounds. The approach involves diverting fish effluents rich in nutrients into a series of seaweed cultivation tanks. Then, the seaweeds were exposed to short-term abiotic stressors (namely, high irradiance, nutrient starvation, and high salinity) to stimulate synthesis of desired ingredients in their tissues. Our methodology enabled high growth rates of up to 25% seaweed biomass increase per day, with significant enhancements in the amount of protein, starch, and minerals within days. Moreover, the seaweeds presented elevated bioremediation capabilities assimilating the ammonia nitrogen, NO3 and PO4 with high uptake rates, and with 50–75% removal efficiencies.
Industrial relevance
The rising public awareness to quality of healthier food products has stimulated growing demand for seaweed supply. Our new approach suggests a promising direction toward the transition from seaweed production of raw, commodity seaweed biomass, to a tailored production of functional seaweeds, enriched with valued compounds that can be utilized in the emerging food and health industries.
... First, trace element in the environment will depend on trace element inputs, either naturally or from anthropogenic activities, through runoffs, rivers and estuaries and even sewage pipes (Herut and Kress 1997). For example, both Cd and Hg are naturally present in very low concentrations in seawater, originating from volcanic activity for example, while anthropogenic activities, including industrial processes, mining activities and even burning of fossil fuels, contributed to increase their concentrations in seawater Bernhoft 2013). ...
Food security, that is guarantying food supply and quality while sustainably managing resources, is closely linked to knowing the biology and ecology of consumed species. In a context of global changes that are threatening seafood safety, it is thus necessary to establish baselines on marine ecosystem functioning, as well as nutrient availability and contamination occurrence in seafood. This is all the more important in Small Island Developing States (SIDS), where populations rely on marine resources for their subsistence, and where capture fisheries resources are the main sources of proteins and micronutrients (i.e. essential trace elements) in local populations’ diet. In spite of the importance of tropical systems in ensuring food security, they remain largely understudied compared to polar and temperate systems. This thesis thus aims to better understand the functioning of tropical marine systems, and to establish a baseline on micronutrient availability and metal(loid) contamination in a wide diversity of capture fisheries resources from the Seychelles (Western Indian Ocean), a tropical SIDS. By investigating trace element concentration patterns at the inter- and intraspecific levels, it was possible to identify intrinsic and extrinsic factors influencing trace element bioaccumulation in tropical capture fisheries resources. We thus highlighted the importance of considering different scales (individual, species, and ecosystem) to better understand essential trace element availability and non-essential trace element occurrence in seafood.
... Thus, we hypothesize that the associations between copepods and microbes are particularly important in environments depleted in nutrients. Warming, pollution, and coastal development are rapidly increasing in the IMS (Amir, 2017;Herut & Kress, 1997;Ozer et al., 2017;van der Hal et al., 2017), which might also alter the interactions between copepods and their associated microbiota. ...
Copepods provide a rich organic microenvironment allowing the settlement and proliferation of microorganisms, forming dynamic microbial hotspots in the oceans. Such symbiotic associations in the plankton were previously hypothesized to be especially developed in warm oligotrophic seas, as they have a potential role in enhancing nutrient availability in biologically-poor waters. Aiming to better understand how copepod microbiomes are shaped in an oligotrophic sea, we characterized microbiota associated with three dominant coastal epipelagic copepod species in the ultra-oligotrophic Eastern Mediterranean Sea using amplicon sequencing of the 16S rRNA gene. Our results show that copepod-associated microbial communities were host-specific rather than determined by seasonal environmental changes. In the filter-feeding copepod with a tendency to herbivory, Temora stylifera , microbial diversity was low and relatively stable throughout the year. In contrast, omnivorous copepods, the ambush-feeding Oithona nana and the mixed-feeding Centropages ponticus , harbored more diverse microbiomes dominated by transient taxa. We suggest that filter-feeding strategy and narrow food spectrum can limit copepod-microbe interactions, while the ambush and mixed feeding strategies combined with omnivory confer higher microbial diversity. Filter feeders may reduce the recruitment of opportunistic microbes by maintaining high fidelity associations, as indicated by the large number of core taxa in T. stylifera . We underline the importance of the copepod-microbe associations in nutrient-impoverished ecosystems, based on predicted enrichment of nitrogen metabolism in the core microbiome, mostly during summer when the shallow coastal waters are nitrogen-depleted.
... First, based on the ability of a parameter to control arsenic mobilisation, pH and TSS are widely reported to control arsenic mobilisation. Acidity and redox potential are sensitive to heavy metals (Lu et al., 2019) and can influence the release of heavy metals (Wen and Allen 1999) and affects their adsorption (Herut and Kress 1997;Gundersen and Steinnes 2003). A study by Zheng et al. (2013) has also indicated dissolved solids' ability to absorb heavy metals. ...
Arsenic contamination is increasingly a serious global health concern, especially in developing countries like Ghana where the intensification of mining activities has resulted in adverse pollution of various water sources within mining communities. To harness the early detection of arsenic contamination in multiple water supply systems, this work aimed to assess and compare the prediction efficiency of different machine learning methods. Novel machine learning algorithms such as extreme gradient boosting (XGB), light gradient boosting (LGB) and generalized regression neural network (GRNN), which are yet to be explored in modelling arsenic concentration in various water supply systems (e.g. surface water and groundwater) were considered in this study. These models were compared with state-of-the-art machine learning methods of decision tree (DT), multivariate adaptive regression spline (MARS), multilayer perceptron neural network (MLP) and random forest (RF). The applied methods were evaluated using the coefficient of determination (R2), Nash–Sutcliff efficiency (NSE) and mean squared error (MSE). The statistical analysis showed that the newly tested models (XGB, LGB and GRNN) produced satisfactory predictions which were comparable to the state-of-the-art methods. Thus, all the methods applied including the newly introduced models have proven efficient in the arsenic modelling task with R2 > 0.93, NSE > 0.92 and MSE <2.35 E−06.
... The Qishon River (South Eastern Mediterranean Sea) include an 11-km-long eutrophic estuary with high concentrations of NO 3 − + NO 2 (33.8-52.5 mg L −1 ) and PO 3− 4 (0.3-1.2 mg L −1 ) (Herut and Kress, 1997;Eliani-Russak et al., 2013;Bar-Zeev and Rahav, 2015), far exceeding the values reported for the Mediterranean's coastal water (Drami et al., 2011;Kress et al., 2019). The high total nitrogen (TN) levels in the Qishon River should theoretically inhibit diazotrophy, and yet, significant heterotrophic N 2 fixation rates were recently reported (0.4-5 nmol N L −1 d −1 ) (Geisler et al., 2020). ...
Recent studies have indicated that heterotrophic diazotrophs are highly diverse and fix N 2 in aquatic environments with potentially adverse conditions for diazotrophy, such as oxic and rich in total nitrogen. In this study, we compared the activity and diversity of heterotrophic diazotrophs associated with aggregates (>12 μm) to free-living cells in the eutrophic Qishon River during the winter and summer seasons. Overall, measured heterotrophic N 2 fixation rates in the Qishon River ranged between 2.6–3.5 nmol N L –1 d –1 . Heterotrophic N 2 fixation was mainly associated with aggregates in the summer samples (74 ± 24%), whereas during the winter the bulk diazotrophic activity was mostly ascribed to the free-living fraction (90 ± 6%). In addition, immunolabeled micrographs indicated the presence of aggregate-associated heterotrophic diazotrophs in both seasons, while phototrophic diazotrophs were also captured during the winter. The richness of free-living and aggregate-associated heterotrophic diazotrophs were overall similar, yet the evenness of the later was significantly smaller, suggesting that few of the species gained advantage from particle lifestyle. The differences in the activity, micro-localization and diversity of the diazotrophic community were mostly attributed to spatiotemporal changes in the ambient C : N ratios (total organic carbon, TOC: total nitrogen) and the TOC concentrations. Taken together, our results shed new light on the contribution of heterotrophic diazotroph associated with aggregates to total heterotrophic N 2 fixation in oxic, highly eutrophic aquatic environments.
... According to all norms, areas with a degree of recreational digression higher than the fourth class should be excluded from the recreational areas, since plantations and ground cover will not be able to recover on their own. [7][8][9][10] An example of the rational use of forest and water resources is the Khlebnikov forest park, located on the diametrically opposite side of the Klyazma reservoir. Thanks to the landscape and architectural activities, there picturesque landscapes which, together with various types of recreation activities, including the water ones, attract many visitors, but there are no negative effects on the ecosystem. ...
... One of the most important indicators of the quality of natural waters, determining the possibility of their use, is the content of heavy metals (HMs), respectively, of their income and migration in the aquatic environment and in the catchment of water reservoirs devoted to the many works addressing this problem in various regions of the world [1], under conditions of relatively low pollution, for example, Upper Volga, Upper Volga water storage reservoirs [2][3][4]. At the same time, there are territories with high anthropogenic load and developed industry, where the receipt of HMs in the environment, including in water reservoirs, can pose a serious problem [5]. ...
One of the most important water quality indicators is the heavy metals content. Heavy metals (HMs) are one of the top pollutants in the list because even very small concentrations of them are highly toxic. The peculiarity of HMs as pollutants is also that there is practically no bio-degradation for them – they only move from one natural reservoir to another, interacting with living organisms and leaving traces of this interaction. Moving from one link of the trophic chain of ecosystems to another, they gradually concentrate in the master links of food chains, as well as in bottom deposits (BD). In particular, HMs can take a long time to gain a foothold in the root stalks of perennial aquatic plants. Excess of their content over the background values in the conditions of the Moscow region is a purely anthropogenic factor. Sources of environmental input can be any activity types: industry, agriculture, motor transport. However, the analysis of the heavy metals input in territories differently located about heat power engineering and oil refining facilities, allows us to assert that the main source is emissions through high pipes of enterprises of ash residues, while there are multiple exceedances of MAC in soils and surface waters, close to the pollution source. As you move away from the pollution sources, the content of HMs in snow, water, soil, and bottom deposits decreases significantly and tends to change over the years, which is associated with changes in the air-mass transport within the region.
... The quick simulation models developed in this study generally simulated particulate heavy metal concentrations well, indicating that pH, SS, T, COD Mn and TP may have some influence on the behavior of heavy metals. Studies have found that pH affects the adsorption and desorption of heavy metals in water column (Herut and Kress, 1997;Gundersen and Steinnes, 2003). Additionally, pH can influence the release of heavy metals in river sediment and suspended matter (Wen and Allen, 1999). ...
Although heavy metal monitoring campaigns are established worldwide, it is still difficult to model heavy metals in aquatic environments with limited monitoring data. In this study, surface water physicochemical indexes and heavy metal concentrations were measured in a drinking water source in the Taihu Lake region, China. Afterwards, indexes including water temperature, pH, suspended matter, turbidity, and total nitrogen, nitrate nitrogen, ammonia nitrogen, total phosphorous, orthophosphate and permanganate index were used to simulate dissolved, particulate and total heavy metal concentrations using artificial neural network (ANN) and support vector machine (SVM) models. Sensitivity analysis showed that simulated heavy metal concentrations were most sensitive to pH. Thereafter, quick simulation models based on five sensitive parameters (pH, suspended matter, water temperature, total phosphorus and permanganate index) allowed for quick simulations of heavy metal concentrations were built. Both ANN and SVM quick simulation models simulated particulate heavy metal concentrations well with most Nash-Sutcliffe efficiency coefficients >0.8. Models performed worse when simulating dissolved and total heavy metal concentrations. Results demonstrate that artificial intelligence models like ANN and SVM are alternative ways to simulate heavy metal concentrations with limited monitoring data. Furthermore, sensitivity analysis may help to identify key factors affecting heavy metal behavior, and to improve environmental monitoring campaigns and management strategies.
... Unlike the extreme oligotrophy of open waters in the Levantine basin, a high load of dissolved nutrients and chl-a characterizes the waters of the port and the bay. The organic enrichment, coupled with the physical conditions (microtidal, high radiation, seasonal stratification), resulted in recurrent plankton outbreaks comprising potentially toxic species (Kimor et al., 1996;Kress et al., 1995;Herut and Kress, 1997). ...
Resting stages of plankton were sampled in the surficial sediments in the port of Haifa, Israel, on the eve of a major port enlargement project. We recorded the structure of the assemblages and examined their relationship with different environments within the port. Our findings reveal a remarkably high diversity coupled with low density and the highest number of oligotrich ciliate cyst types recorded from marine sediments. Near the eutrophic and highly polluted zone of the Kishon estuary ciliates were more abundant than elsewhere in the port, whereas dinoflagellates' abundance was reduced, and these trends held true both for full and empty cysts. Some harmful or potentially toxic species, such as Scrippsiella acuminata, were widespread in the port. The toxigenic species include Alexandrium minutum, Gymnodinium uncatenatum and Lingulodinium polyedrum. Active cells of the unarmoured, bloom-forming Akashiwo sanguinea were identified in the cultures obtained from the incubated sediments.
... Two main point sources of mercury pollution were found in HB: (1) a historically significant point source of elemental mercury discharge from a chlor-alkali plant (Electro-Chemical Industries) located at the northern part of the bay (Fig. 1), which operated until 2004 (Herut et al., 1996); and (2) the Kishon river estuary, located at the southern part of HB, which contains effluent from nearby industries (Herut and Kress, 1997;Herut et al., 1993Herut et al., , 1999. Diffusive sources of atmospheric deposition and runoff should be taken into account as well (Herut and Galil, 2000). ...
... The high level of metal-adsorbed SPM in confluence bay areas is common where heavily polluted river inflows exist (Herut and Kress, 1997;Masson et al., 2006). The results of this study indicate that dredging projects in such areas may be subject to the adverse effects of the riverine SPM. ...
... The ratio of Mn/Fe is lower in all the sampling sites. The depletion of Mn in anoxic and polluted sediments has been reported by several authors (Jung et al., 1996;Herut and Kress, 1997; Guerra-Garcia and Garcia-Gomez, 2005). When sediments are contaminated and usually anoxic, there is a precipitation of copper sulphide and dissolution of manganese oxide which are responsible for the enrichment of Cu and the depletion of Mn, respectively. ...
The study area was Ota ward of Tokyo, Japan, which is well known as an industrial area. Water and sediment samples from nineteen sites were collected to determine the concentration, contamination and pollution level. The study also aimed to clarify the base metal pollution of this region focusing on the effect of urbanization and technogenic impact on sediment and water quality of Nomi River. The concentration of base metals in water and sediments were measured in the liquid extract by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS), respectively. A certified reference stream sediment sample (JSd-2) provided by the Geological Survey of Japan was also analyzed using the same procedure as a check. With few exceptions a majority of base metals showed significant correlation with each other, and with organic matter and fine grained particles (silt and clay). The result showed that most of the base metals (Zn, Cd, Cu, Ni, Pb, Mo and Cr) concentration in water and sediment exceeded the surface water standard, environmental limit and geochemical background values such as Japanese river sediment average value, shale value and continental crust, respectively. According to geoaccumulation index (I geo) values the Nomi River sediments were moderately to strongly polluted by Zn, Cd and Pb. Pollution load index (PLI) values for all the sampling sites were also higher than 1 which indicates progressive deterioration of the site and estuarine quality. Normalization with iron (Fe)
... The depth-averaged metal concentrations were calculated in order to understand their vertical variability in the water column (Fig. 3). The mean vertical profiles of Al and Fe showed similar behavior, presenting smaller concentrations at the surface (1 and 0.8 %, respectively) where the organic matter content in the SS is elevated, and higher concentrations in the bottom layer (2.2 and 1.5 %, respectively) reflecting the high content of inorganic compounds in the SS (Herut and Kress 1997). The high organic matter contents in the SS of the surface layer were as expected because of the high primary productivity at Guabanara Bay (Rebello et al. 1988) and the high freshwater discharge during the survey period. ...
Guanabara Bay is one of the largest embayment in the Brazilian coast, being subjected to a high anthropogenic impact. The goal of this work is to describe the content and dynamics of heavy metals in the suspended sediments of this tropical coastal embayment, and to evaluate exchanges between the bay and the ocean. With this purpose, information on heavy metal concentrations in suspended sediments, and profiles of temperature, salinity and currents were acquired at an anchor station in the central channel of the bay, and coupled with the tidal cycle. The vertical profiles of Al and Fe presented the lowest values in the surface layer and the highest concentrations at the bottom due to their binding to the particulate matter. Conversely, Mn concentrations were lower at the bottom, where it was influenced by the low water temperatures of the salt wedge. Zn and V showed affinity with Fe and Mn oxyhydroxides. Pb, Cd and Hg were subjected to dilution, from mixing with particles that present low metal concentrations. The metal pollution index showed a clear relationship with the tidal stage, with higher values occurring in the ebb tide. The water column was stratified during the survey due to presence of oceanic cold water mass and high freshwaters discharge. As consequence, the residual transport of metals in the surface was toward to the coastal area and near the bottom was toward to the inner bay for the majority of the metals.
... Similar studies associated with river influxes have also taken place in many other coastal Mediterranean areas, e.g. coasts of Spain (Guieu et al. 1991;Liquete et al. 2005), coasts of Israel (Herut and Kress 1997;Goldsmith et al. 2001), Gulf of Lions (Morley et al. 1990;Jeftic 1990;Nicolaou et al. 2006). ...
This study examines the dispersion of heavy metals (Cu and Ld), as pollutant indicators, in the surface sediment of the inner shelf of the north coast of Crete (Gulfs of Heraklion and Malia) on the basis of their source points, in land, and the general circulation of surface shelf waters. Increased values of Cu and Ld have found at the western part of the Heraklion Gulf, close to their terrestrial source, whilst increased values in the Gulf of Malia have been attributed to the presence of an anticyclonic circulation. Introduction The major contribution of anthropogenic metals in a marine coastal area is of terrestrial origin, (mining, industrial, and urban developments) and other human practices near rivers and estuaries [1]. The scope of this work is to investigate the dispersion of trace metals in the sea floor sediments and to correlate their spatial abundance to offshore water circulation pat-terns and the location of their sources. Study area and sampling procedure The study area is located in the northern coast of the Island of Crete (South Aegean) including the Gulfs of Heraklion (to the west) and Malia (to the east). Sediment samples for all analyses were collected on a seasonal basis along 93 stations, which were located from the continental shelf and in depths from 30 m to 100 m (Fig. 1).
... The cliamte of the Far-East is mainly characterized by a summerhumidity season which lasts from April to October. the city of Haifa. The Qishon's water is contaminated by agricultural runoff, various types of industrial effluents, and domestic sewage (Herut & Kress 1997); by heavy metals and a mixture of organic materials (Richter et al. 2003;Herut et al. 1994;Krumgalz 1993) including polycyclic aromatic hydrocarbons (PAHs), alkylated benzenes, halogenated alkanes, and chlorinated aromatic organic compounds; and some radionucleotides. As a result, the lower part of the Qishon River has been denuded for years of its multicellular life forms (Richter et al. 2003). ...
In our study we investigated two polluted rivers of Eurasia from silicate and carbonate regions. We revealed an algal diversity consisting of 184 algal species and cyanoprokaryotes in the Rudnaya River, and 175 in the Qishon River. The distributions of species over the 7 higher taxa were very similar for both rivers with diatom prevealing. Bioindicational analysis in respect salinity, acidification, oxygenation, and organic pollution show that the water is cleaner and the diversity is higher in the Rudnaya River than in the Qishon River. The indices of saprobity S ranged similar. The impact of pollution on Rudnaya River increases downstream. In tha case of Qishon River, the impact of pollution decreases downstream.As a result of CCA, we revealed biosensors group sensitive to borates and fluorides in the case of Rudnaya River and these were: Ankistrodesmus acicularis, А. angustus, Scenedesmus acuminatus, Lyngbya kuetzingii, Neidium ampliatum, and Sellaphora rectangularis. In the case of Qishon River, Audouinella pygmaea, Characium ornithocephalum, and Chamaesiphon amethystinus were found as biosensor species. We found that algal biodiversity is more sensitive to technogenic pollution in the silicate province being more tolerant to the same organic pollutants in the carbonate province. Therefore, the combination of bioindicational methods and statistics are effective for determination of the main factors influencing algal diversity, indicators or biosensing species for the most important environmental variables.
... Trace elements are widely distributed in the Ocean, reflecting chemical equilibria in the water, as well as exchanges with the sediment and atmosphere (Libes, 1992). Trace elements derived from weathering and human activities are added to the coastal environment mainly through rivers and estuaries, atmosphere and sewage pipes (Bryan et al., 1985;Herut and Kress, 1997). Hydrothermal activities in the seafloor have also been recognized as important natural sources of trace elements in volcanic regions (Charlou et al., 2000;Douville et al., 2002), and such sources occur on the Mid-Atlantic Ridge (MAR) off the Azores Archipelago where several important hydrothermal vents have been identified (Cannat et al., 1999;Rona et al., 1986). ...
... The Kishon River is regarded as the most polluted river system in Israel (1,2). The river drains an area of approximately 1100 km 2 and flows through agricultural, domestic, and industrial districts before joining the Mediterranean Sea near the city of Haifa. ...
This study evaluates water genotoxicity of the Kishon River,the most polluted river in Israel that is under restoration. Water samples were collected every other month (January 2001-May 2003) from five sites, and genotoxicity was assayed by the alkaline comet assay using a fish hepatoma cell line (RTH-149). Genotoxicity in the Kishon River was reduced during 2002 as compared to the previous year. The results further revealed fluctuations in genotoxicity levels at all sites throughout the studied period with variations for the same month during consecutive years and seasonality. In general, summer samples were more genotoxic than winter samples. In the vast majority of the 75 water samples, all four parameters for genotoxicity that were employed revealed significant higher genotoxic levels than the controls. Comet percentage values in Kishon River samples were, on average, 1.8-2.4 times higher than controls. Damage score, comet tail length, and cumulative tail length values were 2.2-3.1, 2.4-3.7, and 2.4-3.7 times higher than controls, respectively. The Histadrut Bridge and Haifa fishing harbor (3.0 m depth) emerged as the most polluted sites, whereas Kiryat Haroshet was the least contaminated. Results call for a long-term genotoxicity follow-up plan at the Kishon River in order to assess the possibly evolving chronic genotoxicity state.
... Systematic monitoring along the entire Israeli coast only began in 1988. Between 1988 and 1993 no major contamination by Hg, Pb, Cu, Zn or Cd was found in the lower reaches of coastal rivers, except for the Kishon River which is known to be heavily polluted (Herut et al., 1995;Herut and Kress, 1997;Herut et al., 1999). Most sites were found to be below the EPA criteria for heavily polluted soils and 'background' concentrations (Salomons and Forstner, 1984). ...
In order to determine whether observed trends in total trace metal content were natural or due to anthropogenic inputs, major and trace elements were measured on three size fractions (fine sand (250-63 μm), silt and clay (<63tμm) and clay (<2μm)) of sediment collected off the Mediterranean coast of Israel. Partitioning of trace metals into carbonate/exchangeable, iron oxide and residual phases for each grain size was also determined. The dominant source of particles was Nile derived material. There was a decrease in Fe/Al, Ti/Al and non-carbonate Mg/Al in the fine sand fraction, interpreted as a decrease in heavy minerals towards the north and an increase in K/Al due to increased feldspars and micas. There was a simultaneous increase in CaCO3 both towards the north and onshore in all grain size fractions due to a northward increase in local biogenic fragments and river detritus. This is consistent with circulation and sediment transport models for the southeast Levantine basin. The background trend in trace metals corresponds to changes in mineralogy. While the fine sand fraction appeared free of contamination, in the finer fractions there is a significant enrichment of Zn, and Cd towards the north, which is not accounted for by changes in mineralogy. The sediments were also enriched in Cu, Zn and Cd near Tel Aviv and Hadera. The peaks near Tel Aviv may correspond to waste discharged through the Yarqon and an old sewage pipe, whilst near Hadera, the Alexander and Hadera Rivers and the terminal for a coal-fired power station may be the source of contamination. There was also clear evidence for contamination by Pb in the finest sediments. However, there was no enrichment in Pb around the point sources of the other trace metals, therefore it was concluded that the majority of Pb contamination was from the atmosphere. All trace metal contamination may be subject to 'smearing' by sediment transport, particularly in the clay fraction.
... The Kishon River is regarded as the most polluted river system in Israel (1,2). The river drains an area of approximately 1100 km 2 and flows through agricultural, domestic, and industrial districts before joining the Mediterranean Sea near the city of Haifa. ...
This study evaluates water genotoxicity of the Kishon River, the most polluted river in Israel that is under restoration. Water samples were collected every other month (January 2001-May 2003) from five sites, and genotoxicity was assayed by the alkaline comet assay using a fish hepatoma cell line (RTH-149). Genotoxicity in the Kishon River was reduced during 2002 as compared to the previous year. The results further revealed fluctuations in genotoxicity levels at all sites throughout the studied period with variations for the same month during consecutive years and seasonality. In general, summer samples were more genotoxic than winter samples. In the vast majority of the 75 water samples, all four parameters for genotoxicity that were employed revealed significant higher genotoxic levels than the controls. Comet percentage values in Kishon River samples were, on average, 1.8-2.4 times higher than controls. Damage score, comet tail length, and cumulative tail length values were 2.2-3.1, 2.4-3.7, and 2.4-3.7 times higher than controls, respectively. The Histadrut Bridge and Haifa fishing harbor (3.0 m depth) emerged as the most polluted sites, whereas Kiryat Haroshet was the least contaminated. Results call for a long-term genotoxicity follow-up plan at the Kishon River in order to assess the possibly evolving chronic genotoxicity state.
... Systematic monitoring along the entire Israel coast only began in 1988. Between 1988 and 1993 no major contamination by Hg, Pb, Cu, Zn or Cd was found in the lower reaches of coastal rivers, except for the Kishon River which is known to be heavily polluted [137][138][139][140]. Most sites were found to be below the EPA criteria for heavily polluted soils and 'background' concentrations [46]. ...
The Mediterranean Sea is one of the most nutrient depleted seas and is a characteristic oligotrophic system. The Mediterranean Region, embracing parts of two continents as diverse as Europe and Africa, is a complex geographic, ecological, cultural and socio-political set-up based around the Mediterranean Sea basin. The Mediterranean climate, with mild, wet winters and hot dry summers, has been used as a model for many other regions around the world. Its landscape and monuments continue to be the greatest tourist destination in the entire world. As a consequence, urbanization has been particularly growing along the coastal strip, to accommodate both a permanent and temporary population, with the result being a substantial modification of the coast itself and adverse effects on the quality of the environment. The highly developed industrial countries in the North stand in stark contrast to the countries in the South. These differences have significant implications when addressing environmental issues and particularly those related with the management of persistent toxic substances (PTSs). The descriptions of the contamination of sediment collected from the Mediterranean coast with heavy metals are summarized in this review. The concentrations of Fe, Mn, Ni, Hg, Cd, Pb, Zn, etc. in sediment collected from the Mediterranean coast of eight countries are presented in this review. Most of the published articles about the contamination of sediment in the Mediterranean with heavy metals have been discussed in this work.
... Sanford et al. 1991; Jago et al. 1994). The semi-diurnal variations of SPM concentrations observed during spring tides (Figs. 2 and 4) were very small compared with variations of SPM in other estuaries (Turner et al. 1994; Heruk and Kress 1997; Austen et al. 1999). The range of variation observed in this work and reported previously by Coutts-Smith (1998) were, in fact, smaller than SPM variations at neap tide elsewhere (Gelfenbaum 1983; Vale and Sundby 1987). ...
Particulate trace metal (Cu, Cr, Ni, Pb and Zn) and major element (Fe, Mn and Al) concentrations have been determined following intensive sampling over two consecutive spring tidal cycles in the 'turbidity maximum zone' (TMZ) of the Port Jackson estuary, Australia. Salinity, temperature, pH, dissolved oxygen, suspended particulate matter (SPM) and chlorophyll a were also determined. A three-factor analysis of variance was used to test temporal variability in concentrations of particulate trace metals and major elements as a result of tidal oscillation. Estuarine master variables, such as temperature and pH, varied within a narrow range; nevertheless, the tidal signal was clear for surface and bottom waters. In surface water, no variance was detected in SPM concentrations between consecutive tidal cycles or between tidal stages (i.e. flood, ebb and slack water). In bottom water, however, SPM concentrations were significantly higher (PА.05) at flood tide than at slack high water and ebb tide. Concentrations of particulate trace metals and major elements in surface water do not display significant variability between tidal cycles or stages. Nevertheless, differences within each tidal stage were significant (PА.05) for all elements. In bottom water, only particulate Fe and Al exhibited significant differences (PА.05) between tidal cycles, whereas particulate Ni was the only trace element that presented significant differences (PА.05) between tidal stages, following the distribution of SPM, with highest concentrations at flood tide. Among the metals studied, significant variation was found at all three temporal scales examined (i.e. from hours to consecutive tidal cycles), although the patterns of variation were different for each metal. The semi-diurnal fluctuation of SPM and particulate trace metal concentrations during spring tides is interpreted as a resuspension-deposition cycle caused by cyclical oscillations of bottom currents. The results are discussed in the context of the implications of tidal cycle influence on the geochemistry and cycling of particulate trace metals in the Port Jackson estuary.
... Similar studies associated with river influxes have also taken place in many other coastal Mediterranean areas, e.g. coasts of Spain (Guieu et al. 1991;Liquete et al. 2005), coasts of Israel (Herut and Kress 1997;Goldsmith et al. 2001), Gulf of Lions (Morley et al. 1990;Jeftic 1990;Nicolaou et al. 2006). ...
The present study investigates the distribution of trace metals (Zn, Hg, Cd, Cu, and Pb), as indicators of pollution, in the
surficial offshore shelf sediments along the northern coast of Heraklion Prefecture (Crete, Mediterranean Sea). The concentrations
and the spatial distribution of the different trace metals, in relation to the sedimentological characteristics and the water
circulation pattern of the entire continental shelf, are associated with human inshore sources of pollutants located along
the coastline of the study area. Although the trace metal concentrations measured are higher than the background values, they
are not considered to be dangerous to human health, as they are lower than the standard values given by the World Health Organisation,
with only a few localised exceptions. Furthermore, results reveal the important role of local hydrodynamism that moves fine-grained
material and associated trace metals offshore (seawards to wave breaking zone) and then transports them eastwards by entrapping
them in the prevailing offshore shelf-water circulation.
Particle backscattering efficiency (Qbbe(λ)) relates closely to particle type and links light backscattering with biogeochemical properties. However, knowledge gaps about Qbbe(λ) persist in the Pearl River Estuary (PRE). We measured Qbbe(λ) within the three transects in the PRE and investigated its relationships with particle composition and size. The results show that particle size influences Qbbe(λ) more than composition. Vertical heterogeneity of Qbbe(λ) was observed; high Qbbe(λ) values spanned vertical columns due to dynamic river-sea interactions, showing distinct layers with higher concentrations at the surface and bottom, but lower mid-layer values unaffected by rivers. Transects influenced by river discharge showed elevated Qbbe(λ) due to high inorganic particle inputs, while coastal currents influenced bottom values via sediment resuspension. This enhanced understanding of Qbbe(λ)'s spatial-temporal variations in the South China Sea is vital for better predicting particle characteristics from optical data.
The distribution of dissolved iron (dFe) and particulate iron in the estuarine system was studied where in-situ water sampling stations were selected at Bagan Pasir, Perak. The concentration of dFe was 1.17±0.28 mg/L on average at the estuary, while in freshwater samples its concentration was 0.08±0.00 mg/L. This study found that the concentration of particulate Fe in freshwater system was higher than that in the estuary system. The Fe concentration was 0.95±0.03 mg/kg and 0.80±0.18 mg/kg at the freshwater and estuary systems, respectively. We have applied a distribution coefficient (K D) in order to quantify the partitioning of Fe between the particulate (>0.45 μm) and dissolved (<0.45 μm) phases. The K D value of Fe in the freshwater system was much higher compared to that in the estuary, where the K D value was 12.18 in freshwater and 0.48-1.31 in the estuary. This indicated that Fe in this area has a strong affinity with the particulate phase in a freshwater system and this is probably due to the anthropogenic input. On the other hand, Fe may exist in colloidal or organic ligands which probably originate from surface sediment or a biological process in water columns at the estuarine area.
Se estudió la distribución y comportamiento de los metales pesados (Fe, Mn, Ni, Cr, Cu, Cd, Pb y Zn), su especiación en la fracción disuelta y en el material en suspensión, así como su relación con los procesos fisicoquímicos en las aguas superficiales de la cuenca baja y pluma del río Manzanares, Edo. Sucre, Venezuela, durante el período comprendido entre julio de 1996 y junio de 1997. Para alcanzar tales fines, se determinaron los parámetros fisicoquímicos temperatura, salinidad, pH, oxígeno disuelto, amonio, nitritos, nitratos, fosfatos, silicatos, material en suspensión y la especiación para algunos metales pesados en las fracciones antes mencionadas en veintidós (22) estaciones establecidas en la cuenca baja y pluma del río. La temperatura del agua superficial presentó un comportamiento estacional que está estrechamente relacionada con las condiciones climáticas que prevalecen en los diferentes períodos (lluvia y sequía) del año y los diagramas T-S sugieren la presencia de una mezcla de dos cuerpos de agua (río y de mar) de diferentes propiedades fisicoquímicas. Durante la época de sequía dominan los procesos heterotróficos en el río y zona de mezcla, ocasionando disminuciones de pH y oxígeno disuelto, los cuales fueron afectados por el dragado que se estaba realizando en la zona. El material en suspensión se incrementó en los meses de lluvia (julio a noviembre), alcanzando el máximo valor en septiembre (1075 mg/l). Las concentraciones de amonio fueron más altas durante la estación seca como consecuencia de la oxidación de la materia orgánica transportada en el río, debido al mayor tiempo de residencia de las aguas. Los nitritos, nitratos, fosfatos y silicatos están linealmente relacionados con el material en suspensión (r > 0,60), con los mayores valores durante el período de lluvia. Los flujos de metales pesados se incrementaron durante el período de lluvia, debido a su asociación con el material en suspensión. Las concentraciones totales de los metales en el material en suspensión de las aguas del río manzanares fueron: no detectado a 0,11 µmol/l para el Cd; no detectado a 8,21 µmol/l para el Zn; no detectado a 0,63 µmol/l para el Cu; Cr: no detectado a 1,47 µmol/l; Fe: 0,54-558,80 µmol/l; Mn: 0,02-11,67 µmol/l; Ni: no detectado a 1,62 µmol/l y no detectado a 0,17 µmol/l para el Pb, mientras que en la fracción disuelta total los niveles estuvieron entre: no detectado a 0,01 µmol/l para el Cd; Zn: no detectado a 5,13 µmol/l; Cu: no detectado a 0,10 µmol/l; Cr: no detectado a 0,02 µmol/l; Fe: no detectado a 2,56 µmol/l; Mn: no detectado a 1,03 µmol/l; Ni: no detectado a 0,10 y el Pb entre 0,02 µmol/l. En general, los metales evaluados presentaron un comportamiento no conservativo con remoción a bajas salinidades debido a la floculación por formación de oxihidróxidos de Fe y Mn como consecuencia de los cambios de pH y fuerza iónica que ocurre cuando se mezclan las aguas dulces con las marinas, así como desorción de los metales adsorbidos en la superficie de las partículas suspendidas y sedimentos, tanto orgánicas como inorgánicas, por los iones Na+ y K+ más abundante en el agua de mar, además de observarse aportes a todo lo largo de la pluma debido a las actividades humanas que se desarrollan en la zona. De igual manera se observan concentraciones elevadas de Cd, Cu, Zn, Mn y Pb adsorbidos en el material en suspensión, como carbonatos y/o oxihidróxido de Mn reactivo, los cuales pueden ser incorporados más facilmente a la cadena trófica o liberarse para ser incorporados de nuevo al agua, mientras que el Cr, Fe y Ni están mayormente asociados a los minerales de arcilla (principalmente aluminosilicatos), lo cual revela que el primer grupo de metales pueden tener su origen en las actividades antrópicas que se desarrollan en la región que conforma la cuenca baja del río y su desembocadura.
Los ríos son el principalvehículo de transportede constituyentes químicoshacia el medio marino, especialmentede metales pesados. Numerosos estudiossobre el comportamiento de estos elementosquímicos en estuarios, muestran quelos procesos físicos, químicos, biológicose hidrodinámicos que allí tienen lugarcumplen un papel fundamental y variableen relación con el flujo de metales desdetierra hacia el mar (Zhang et al., 1992;Yeats, 1993). Igualmente se ha reconocidoque las descargas de los ríos influyenen la variabilidad espacial y temporal delos metales pesados (Gibbs, 1977;Palanques, 1994). Por otra parte, los ríoscontribuyen con significantes aportes demateria orgánica e inorgánica. Los metalestrazas que están asociados a la materiaorgánica son liberados durante el procesode degradación de la misma(Magnusson y Rasmussen, 1982; Valette-Silver,1993).
Rivers in the Eastern Mediterranean, Israel in particular, are small and located mostly in the coastal plane. In the first step of ecosystem assessment, 671 species of algae and cyanobacteria belonging to nine taxonomic divisions were revealed by our research during 2002-2009 in the Yarqon, Alexander, Hadera, Qishon, and Oren rivers in the coastal plane, the Lower and Upper Jordan Rivers in the rift valley, as well as the Zin stream in the Negev Desert. This new book presents and discusses research which suggests that in semiarid environments the influence of anthropogenic factors is strongly modulated by climatic impacts causing a marked decrease of species richness in aquatic ecosystems from north to south.
El estudio de metales traza en cuerpos de agua, sedimentos y organismos, es importante para establecer sus niveles naturales, variabilidad y origen, principalmente en las áreas más sensibles a la contaminación, como son estuarios y bahías. El desarrollo industrial ha tenido su asiento, en un porcentaje bastante significativo, en las riberas de ríos, estuarios y bahías, descargando allí
los efluentes de desechos que contienen grandes cantidades de sustancias nocivas, asumiendo que estas son usualmente dispersadas y transformadas por el mar.Dentro de esas sustancias, los metales traza constituyen un caso especial, ya que no se degradan y, una vez depositados, permanecen en el medio ambiente marino sin sufrir prácticamente ningún cambio cualitativo.
The speciation of the heavy metals Cd, Zn, Cu and Cr was studied in the particulate fraction in the plume of the Manzanares river, Sucre State, Venezuela, during the rainy (July-November) and dry periods (January-April), in 22 stations along of the river plume. It was found that the material in suspension increases during the rainy period, reaching the maximum value in September (1075 mg/l). The flows of heavy metals increased during the same period, due to their association with the material in suspension. Total average concentrations of the metals in the particulate fraction were: not detected (n.d.) to 0,112 mu mol/l for Cd; n.d, to 8,211 mu nol/l for Zn; n.d to 0,780 mu mol/l for Cu; and n.d to 2,075 mu mol/l for Cr. In general, the metals evaluated showed a non conservative behavior with desorption of the metals from the suspended particles and silts, both organic and inorganic, due to exchange with Na(+) and K(+), more abundant in sea water. Contributions along the plume due to human activities that are developed in the area were observed. Similarly, high concentrations of Cd, Cu and Zn were observed in the silts at the bottom and in the particles in suspension such as carbonates and/or Mn oxihydroxide, which can be incorporated more easily to the trofic chain or be liberated, to be incorporated again into the water. Cr is mostly associated to the clay minerals (mainly aluminum silicates). This shows that the first group of metals has its origin in anthropogenic activities taking place in the region that conforms the low basin of the river and its outlet.
The quality of marine waters depends to a large extent on the density of phytoplankton (as chlorophyll a) and suspended particulate matter (SPM), and their composition. The water quality at two 'hot spot' areas along the Mediterranean coast of Israel was mapped with the hyper-spectral Compact Airborne Spectrographic Imager (CASI) sensor during two airborne campaigns (April 1997 and October 1999). The present study demonstrates the advantage of hyper-spectral remote sensing techniques as a rapid synoptic monitoring tool in coastal sites affected by land-based point sources of nutrients and particles. The coastal sites are characterized by patchy distribution and sharp concentration changes of SPM and Chl a. It is suggested that integration of CASI in compliance monitoring at 'hot spot' areas can provide vital information on the state of the environment and on the effectiveness of pollution control measures taken.
This study explores the role of transparent exopolymer particles (TEP) as an additional carbon source for heterotrophic microbial activity in the eutrophic Qishon estuary. From the coastal station and upstream the estuary; TEP concentrations, β-glucosidase activity, bacterial production and abundance have gradually increased. TEP were often found as bio-aggregates, scaffolding algae, detritus matter and bacteria that likely formed “hotspots” for enhance microbial activity. To further demonstrate the link between TEP and heterotrophic bacterial activity, confined incubations with ambient and polysaccharide-enriched estuary water were carried out. Following polysaccharide addition, elevated (~50%) β-glucosidase activity rates were observed, leading to TEP hydrolysis. This newly formed bioavailable carbon resulted in significantly higher growth rates, with up to a 5-fold increase in heterotrophic bacterial biomass, comprising mostly high nucleic acid content bacteria. Taking together the findings from this research, we conclude that even in highly eutrophic environments heterotrophic bacteria may still be carbon limited. Further, TEP as a polysaccharide matrix can act as a metabolic surrogate, adding fresh bioavailable carbon through tight associations with bacteria in eutrophic ecosystems such as the Qishon estuary.
We use multiple stable isotope measurements in two highly stratified estuaries located along the Mediterranean coast of Israel (the Yarqon and the Qishon) to explore the consumption of sulfate through the anaerobic oxidation of methane (sulfate-driven AOM). At both sites, pore fluid sulfate is rapidly consumed within the upper 15-20 cm. Although the pore fluid sulfate and dissolved inorganic carbon (DIC) concentration profiles change over a similar range with respect to depth, the sulfur and oxygen isotopes in the pore fluid sulfate and the carbon isotopes in the pore fluid DIC are fundamentally different. This pore fluid isotope geochemistry indicates that the microbial mechanism of sulfate reduction differs between the studied sites. We suggest that in the Yarqon estuary, sulfate is consumed entirely through AOM, whereas in the Qishon, both AOM and bacterial sulfate reduction through organic matter oxidation coexist. These results have implications for understanding the microbial mechanisms behind sulfate-driven AOM. We compile data from marine and marginal marine environments that supports our conclusion that the intracellular pathways of sulfate reduction varies among environments with sulfate-driven AOM. The data can be used to elucidate new pathways in the cycling of methane and sulfate, and the findings are applicable to the broader marine environment.
This study provides data on the fluvial sediment transport at the Eastern Mediterranean, an area in which the regional importance for comparative study has often been raised by investigators but the data are rather scarce. We analysed long- and short-term hydrologic and sedimentological data from one of the largest coastal streams of Israel, Qishon River (1100km2), and its estuarine environment. The results indicate that during 65 years (1944-2009), a total 140 floods have contributed to the sea an amount of approximately 2.58×106 tons of sediment. During this period, (i) the number of floods with a return period of more than 10years has almost doubled during the last 30years, and (ii) the mean annual discharge during last 10years increased by approximately 175%. The analysis of the short (2years) hydrological and sediment data revealed that approximately 30% of the upstream channel loads do not reach the river mouth and are deposited along the channel bed, even during major flood events. This observation was attributed largely to the facts that the lower river bed is incised below sea level, to the very low slopes and to the correspondingly low stream power and transport capacity. The results of this study highlight the effect of interchannel dynamics as well as the constraints of interaction between fluvial system and estuarine processes on sediment transport.
The aim of the present study is to understand the particulate heavy metal behavior in distinct tidal regimes(neapand spring tides) and river discharges (dry and rainy season). The average heavy metal concentration observed in the presente study are in accordance with previous Works developed in the lower Paraíba do Sul Basin, as well as with the world average. The only exception was Zn that presented higher values in the present study. Aluminum and iron presented higher average concentrations during the high riverine discharge periods; the other studied metals (Mn and Zn) presented an opposite trend with higher concentrations during the low discharge period. The Al and Fe behavior is related to the increase in the surface runoff during the rainy season, due to the soils of the drainage basin being enriched in these elements.The behavior of the other studied metals are probably related to a different source (industrial and urban wastes) and the dilution effect caused by the raise of the river discharge and the input of a suspended particulate matter (from the lower drainage basin) impoverished in these elements. During the low discharge period the average metal concentrations were generally higher during the neap tide sampling, when compared with the spring tide sampling. In the high discharge period no statistical difference could be observed between the distinct tidal regimes, this trend is probably related to the stronger riverine influence inside the PSR Estuary during the higher discharge period.
The hepatic level of metallothionein (MT) mRNA in the sparid fish Lithognathus mormyrus, was used as bioindicator for detecting transition metals pollution in Mediterranean marine habitats. Hepatic MT mRNA levels in feral fish, sampled from different contaminated Haifa Bay locations were compared to in vivo laboratory studies using cadmium as a representative contaminant. In the laboratory, dose response experimental results (27°C), were compared with the results of a similar experiment (21°C; Tom et al., 1998). Temperature significantly influenced MT mRNA induction in livers of L. mormyrus. Hepatic cadmium levels were measured during the 21°C induction and the degradation experiments and their effect on MT mRNA degradation is discussed. In the field study, hepatic MT mRNA levels were high in the fish sampled near polluted areas and lower in less polluted sites. These results indicate the sensitivity of fish MT mRNA to transition metal fluctuations in the field.
Los ríos son el principal
vehículo de transporte
de constituyentes químicos
hacia el medio marino, especialmente
de metales pesados. Numerosos estudios
sobre el comportamiento de estos elementos
químicos en estuarios, muestran que
los procesos físicos, químicos, biológicos
e hidrodinámicos que allí tienen lugar
cumplen un papel fundamental y variable
en relación con el flujo de metales desde
tierra hacia el mar (Zhang et al., 1992;
Yeats, 1993). Igualmente se ha reconocido
que las descargas de los ríos influyen
en la variabilidad espacial y temporal de
los metales pesados (Gibbs, 1977;
Palanques, 1994). Por otra parte, los ríos
contribuyen con significantes aportes de
materia orgánica e inorgánica. Los metales
trazas que están asociados a la materia
orgánica son liberados durante el proceso
de degradación de la misma.
Excitation–emission matrix fluorescence spectroscopy, combined with parallel factor analysis and measurements of UV absorption and dissolved organic carbon (DOC) concentrations, was used to trace the footprints of industrial effluents discharged into the lower Kishon River (Israel). The lower Kishon River typifies streams that are affected by seawater tidal intrusion and represents an extreme case of severe long-term pollution caused mainly by a variety of industrial effluents. The industrial effluents may contribute about 90%, in terms of biochemical oxygen demand, of the total organic carbon discharged into the lower Kishon River. Water samples were collected along the river, including the points of effluent discharge from industrial plants, between November 2005 and September 2006. Two types of fluorescent components characterized the fluorescence of the lower Kishon River water: component I corresponded to humic-like matter and component II spectrally resembled material known to be associated with biological productivity, but different from typical tryptophan-like fluorophore. These fluorescent components and other substances that absorbed light at 254 nm contributed to the DOC pool that resisted riverine microbial degradation under laboratory conditions, and that constitutes up to 70% of the overall riverine DOC. The variations in DOC concentration, absorbance at 254 nm, and concentration of humic-like matter (characterized by component I) correlated with the distance from the sea and the water electrical conductivity, and were linked to seawater tidal intrusion. The increased concentration of component II, as well as its enlarged fraction in the overall riverine DOC pool, was found to be associated with the location of major inputs of the industrial effluents. These findings support the use of this fluorescent component as an indicator of industrial pollution in such severely contaminated riverine systems.
The shelf area is the largest morphological unit of the Marmara Sea and is subjected to increasing population, urbanization, and industrial activities. Metal contents (Al, Fe, Mn, Cu, Pb, Zn, Ni, Cr, Co and Hg) of the surface sediments from the shelf areas of the Marmara Sea generally do not indicate shelf-wide pollution. The variability of the metal contents of the shelf sediments is mainly governed by the geochemical differences in the northern and southern hinterlands. Northern shelf sediments contain lower values compared to those of the southern shelf, where higher Ni, Cr, Pb, Cu and Zn are derived from the rock formations and mineralized zones. However, besides from the natural high background in the southern shelf, some anthropogenic influences are evident from EF values of Pb, Zn and Cu, and also from their high mobility in the semi-isolated bay sediments. Anthropogenic influences are found to be limited at the confluence of Istanbul Strait in the northern shelf. However, suspended sediments along the shallow parts of the northern shelf were found to be enriched in Pb and Hg and to a lesser degree in Zn, reflecting anthropogenic inputs from Istanbul Metropolitan and possibly from the Black Sea via the Istanbul Strait.
Nine trace elements of biological concern: Cr, Co, Cu, Cd, Ni, Pb, Hg, Zn and Ag were investigated in the sediments of the most important coastal steams in Israel. All of these are subjected to some degree of domestic and/or industrial sewage input with the consequent liability of contamination by trace metals. The Ayyalon, Gadura, Qishon and locally the Hadera rivers contain sediments exhibiting severe pollution effects. There is a danger of infiltration through the soils into the groundwaters as well as exposing nearshore fauna to sediments contaminated by possibly toxic trace metals. The other rivers bear smaller levels of trace metals; however, an increase of the Pb and the Zn levels occurs near major highways.
Seven transition metals—cadmium, cobalt, copper, chromium, nickel, lead and zinc—were measured in the waters and the sediments of the Qishon-Gadura river system, Israel's second largest. Biologically significant amounts of environmental contamination of Cd, Cr, Pb and Zn are being added to the Gadura tributary throughout its course. While the build-up is a potential biological threat, it is the high pH of several of the effluent waters that inhibits the metal mobility. Ironically, therefore, a sudden stoppage of the pollution (before other corrective measures are taken) appears to present a greater biological danger to the Qishon River and Haifa Bay than a continuance of the pumping of these wastes into the river.
The trace metal contamination of estuarine sediments of the Kishon river, running through a large industrial zone of Israel, was studied. The sediments were analysed for trace metal (copper, cadmium, iron, lead, mercury and zinc) contents, organic matter content, mineralogical composition and carbonate content. Significant intercorrelations between cadmium, copper, zinc, iron, carbonate content and fluorite (CaF2) content were observed for Kishon river sediments. It was shown that the Kishon river estuary acts as an efficient trap for anthropogenic trace metals, propably through fluorite precipitation. The important processes for the movement of trace metals from the Kishon river to Haifa Bay appear to be the horizontal transport of contaminated fine grained particles along the river bottom, and transport of trace metals in soluble forms. The trace metal content in Kishon river sediments has considerably increased during the last 14 years.
Total mercury concentrations were determined in surficial sediments, eleven species of benthic organisms and six species of fish from Haifa Bay, Israel. The results show that essentially all of the shallow water zone of the Bay receives anthropogenic mercury. A mercury-cell chlor-alkali plant was identified as the source of pollution. Surficial sediments in the vicinity of the plant, containing up to 0·99 μg Hg/g dry weight, were up to 157 times enriched in mercury relative to an unpolluted area. Mercury levels in the benthic organisms reflected the levels in the sediments. Maximal concentrations reaching 38·7 and 18·2 μg Hg/g dry weight were found in the carnivorous gastropod molluscs Arcularia circumcinta and Arcularia gibbosula, respectively. In all fish species, specimens caught in Haifa Bay had higher mercury concentrations in the muscle tissue than specimens caught south of the Bay. A maximal value of 1·66 μg Hg/g wet weight was recorded in Diplodus sargus.
The sediments of the lower reach of the Kishon river, its harbours and estuary, sampled in 1989-1991, were highly polluted by trace metals and petroleum derived compounds released by the adjacent industries. The contamination was highest in the sediment deposition area of the Kishon fishing harbour and decreased seaward. River-borne pollution was also evident in Haifa Bay opposite the Kishon estuary. Contaminants trapped in the sediments of the lower Kishon river system can reach the marine environment through bottom transport of sediment particles and also as a result of disposal at sea of dredge spoils from the river channel and harbours. On the basis of the findings of the study, it was recommended to stop the long-time practice of dumping dredge spoils from the Kishon fishing harbour into the relatively clean Haifa Bay and to use instead an offshore deep water disposal site.
Trace metal solid-solution partitioning, represented by KDs, has been studied along a salinity gradient created by batch mixing of end-member samples taken from the Humber Estuary. The KDs decrease with salinity for Cd, due to complexation of the dissolved form with chloride ions, and Cs, due to competition from sea water cations for particle sorption sites. Although KDs for Zn were relatively invariant, there is evidence to suggest that a reduction in KD with salinity would be effected under more acidic (pH < 7·6) conditions. An increase in KD for Mn with salinity by more than an order of magnitude is related to heterogeneous oxidative precipitation onto pre-existing particles. The extent of metal desorption is a function of end-member KDs the concentration of seaward advecting riverine particles and the reversibility of sorption. Thus, mass-balance calculations predict the extent of desorption of Cd which is loosely held to particle surfaces, but cannot be applied to Cs because a significant fraction (70%) of ions is irreversibly lodged within particle matrices. Although KDs for Cd, Cs and Zn are independent of particle concentration, maintenance of a constant partitioning with change in particle concentration requires a shift in the relative proportions of metal in solution and particle bound (w/w). This effect is manifested by the pronounced removal of trace constituents in an estuarine turbidity maximum and can be quantified by incorporating KDs into a sorption model.
Haifa Bay, although adjacent to major chemical and other industries, showed no significant contamination of Cu, Cd, Pb and Zn in the sediments or benthic biota except for one station opposite the polluted Kishon river estuary. There was moderate to low Hg contamination throughout the bay, derived from the outfall of a chlor-alkali plant. The levels of Hg in the surficial sediment and biota have not changed significantly over the last 7 years, a period when effluent treatment was operating at the chlor-alkali plant. Using pollutant laden particles from recognized point sources as tracers for sediment transport, it was concluded that the southern part of Haifa Bay is an area of net sedimentation. No sediment from this area was detected further north in the bay. Sediments introduced at the north of the bay spread both north and south. Within most of the bay there has been no major sediment accumulation or erosion over the past 7 years.
THE importance of biogeochemical interactions in estuaries is widely recognised1,2,4–6; in particular, theoretical models of estuarine speciation of trace metals7 and of the pH–carbonate system8 predict that sharp changes of thermodynamic equilibrium conditions should occur at very low salinities (<1‰). However, because of the limitations of conventional sampling strategies12, the chemical properties of this freshwater–seawater interphase (FSI) have not been adequately characterised. Instead, the expected variability has usually been represented by a scatter of spatially and temporally unresolved data points1,3,5,6. Over the past two years, we have carried out periodic detailed investigations of the immediate mixing of the fresh and brackish water in the Tamar Estuary, South West England and we present data here for 11 determinands which point to the FSI as being an important site for chemical and biological processes in estuaries.
Concentrations of mercury, lead, copper, zinc, cadmium, iron and partially chromium, manganese, nickel and aluminium, were recorded in surface sediments at the lower reaches of 11 rivers from the Mediterranean coastal zone of Israel, during 1988–1993. Excluding the lower Kishon river, no major contamination was found at most of the stations when trace metal concentrations were normalized against iron concentrations (trace metal/ iron ratios) and compared to levels recorded in stream sediments from the southern drainage basin of the Kishon river. Minor enrichments found in part of the rivers are attributed to land-based point sources of pollution. Variations in trace metal concentrations at the estuaries are related to high influx of fine-grained sediments transported by heavy floods during rainy winters, which later are resuspended and transported seaward by bottom currents.
Environmental relaxation, defined as the rate of return of a polluted environment to an acceptable state following a reduction in the input of contamination, was evaluated for the case of mercury pollution in northern Haifa Bay (Israel) on the basis of the long-term record of mercury levels in sediment cores and biota. Mercury was found to decrease with a half-time of 2, 5 and 6–33 years in filter-feeding bivalves, fish and sediments, respectively, after the influx of mercury into the area (from a chlor-alkali plant) was drastically reduced. The present levels of mercury in edible fish do not represent a risk to human health. The removal of mercury from the sediments is probably by particle resuspension and subsequent seaward transport. Although the mercury concentrations in the sediments will probably remain above background for a long time, the associated ecological risk does not appear to be high. It is concluded that evaluations of the environmental relaxation of different types of ecosystems, with respect to various contaminants, may provide important input to decision-making on marine waste disposal.
Concentrations of mercury, lead, copper, zinc, cadmium, iron and aluminium were recorded in coastal and river mouths surficial sediments, collected along the Mediterranean coast of Israel, during 1988–1991. The levels of trace metal concentrations when normalized against Fe concentration (trace metal/iron ratios) indicated no contamination at most of the stations along the coast. Enrichment of Hg, Cu, Zn and Cd attributed to land-based point sources of pollution, was found in the estuaries of the Kishon and Yarkon rivers. The normalized Pb, Cu and Zn data showed a trend of increasing values from the south toward the north. This S-N trend could be a result of three processes which may be occurring simultaneously: progressive mixing between sediment with a low trace metal/iron ratio in the south, which probably represents a single source derived from the Nile region with (a) non-point source input of pollutants by atmospheric transport, or (b) with point sources of pollutants introduced by rivers and streams, or (c) a natural change in the mineralogy of the sediments along the coast with a relative increase in the trace metals or a decrease in iron as one progresses further north. The relative importance of these three possible processes remains to be established.
Suspended sediment samples collected from the North Sea and during axial surveys of five major North Sea estuaries (Humber, Thames, Scheldt, Weser, Elbe) have been analysed in a consistent manner for leachable metals, specific surface area and carbon.Particulate trace metal (Co, Cr, Cu, Ni, Pb and Zn) concentrations were similar in each estuary and estimates of fluxes to the North Sea based on an empirically derived prediction equation therefore reflected catchment size. Concentrations generally decreased seawards as a result of mixing of riverborne sediment of high metal concentration with material of marine origin of relatively low metal concentration, although in the Humber, substantial anthropogenic inputs at high salinities were responsible for more ambiguous distributions.In contrast, profiles and concentrations of Fe and Mn, implicated as being important to particle surface and compositional properties, exhibited significant yet explicable inter-estuarine variability (e.g. Humber during winter: Fe = 12·0 mg g−1, Mn = 0·99 mg g−1; Elbe during summer: Fe = 6·6 mg g−1, Mn = 3·08 mg g−1).Comparable data such as these serve as valuable baselines for any future international long-term water quality monitoring programme of European estuaries.
The distribution We wish to thank Y. Gertner, G. Fainshtein, E. Shoham Frider and and chemical composition of particles in a macrotidal estuary
- A Turner
- G E Millward
- A O Tyler
Turner, A., Millward, G. E. and Tyler, A. O. (1994) The distribution We wish to thank Y. Gertner, G. Fainshtein, E. Shoham Frider and and chemical composition of particles in a macrotidal estuary. the captain and crew of the R/V Shikmona for their help with sampling Estuarine and Coastal Shelf Science 32, 325-346.
Transition metal contamination in the Qishon river system, Israel. Environmental Pollution 6, 281-288. respectively, than the surface sediments along the lower Kronfeld Aspects of trace metal con-centration in the coastal rivers of Israel
- J Kronfeld
- I Navrot
Kronfeld, J. and Navrot, I. (1974) Transition metal contamination in the Qishon river system, Israel. Environmental Pollution 6, 281-288. respectively, than the surface sediments along the lower Kronfeld, J. and Navrot, I. (1975) Aspects of trace metal con-centration in the coastal rivers of Israel. Water, Air and Soil Kishon River system (Fig. 7).
Sediment transport and sedimentation in the estuarine environment
- Postma
The distribution and chemical composition of particles in a macrotidal estuary
- Turner