Edku Lake Research Articles

Ultrastructural and SEM-EDX Analysis Characterizations of the Pecten Oculi of the Eurasian Stone-Curlew (Burhinus oedicnemus): New Insights to Its Migratory Adaptations With Northern Egyptian Coast.

Our study represents the first attempts to describe the ultrastructure features in addition to SEM-EDX analysis of the pecten oculi of the nocturnal, visually active Eurasian stone-curlew. The present study was carried out on 10 normal pecten oculi from the migrant Eurasian stone-curlew (Burhinus oedicnemus) that was captured from the Northern Egyptian coast, Edku Lake, Edku, Behera, Egypt. The intraocular folded quadrilateral fan black pecten oculi was observed on the posteroinferior wall of the eyeball. The pecten oculi had 18-20 pleats, with narrow spaces in-between. Our SEM findings showed a tortuous, coiled pecteneal surface due to numerous blood capillaries. The apical part was oriented toward the ciliary body, but the basal part was derived from the retina, just behind the optic nerve. The outer pleat surfaces are covered by the vitreopecteneal limiting membrane, which carries numerous hyalocyte cells on the outer pleat surface. The transverse sections revealed numerous blood capillaries surrounded by numerous melanin granules. Each basal part was surrounded by a thin, elevated ridge. Our SEM-EDX analysis revealed that carbon is the highest (half percent), oxygen represents about one-third, and nitrogen is one-fifth percent of all elements. The lowest elements are sulfate at the apical part and phosphorus in the middle and basal parts. In conclusion, our findings reveal that the number of pecteneal pleats is related to the nocturnal active visual pattern and the lifestyle of this migratory bird.

Assessment of The Groundwater Around Edku Lake

Assessment of The Groundwater Around Edku Lake

Assessment of Soil Degradation Around Edku Lake

Assessment of Soil Degradation Around Edku Lake

Estimation of tilapia fish quality in Lake Edku through physiological analyses regarding trace element accumulation, antioxidant enzymes, proximate composition, and human health risk assessment as the ultimate consumer

Lake Edku is one of the most important northern lakes whose people with limited income depend on its fish as a cheap source of food. In 2016, the Egyptian government has developed a strategy to develop the historical and economic value of northern lakes included Edku Lake within the Egypt vision 2030. That is why this study was conducted to monitor the physiological state of tilapia fish caught by different fishermen around the Edku lagoon. The results reported that the highest concentration was for As in O. aureus (2.16±0.3μg/g), which increased the safe limits permitted by FAO/WHO, EU' and the EOSQC. S. galilaeus was recorded the lowest Hg level (0.35±0.1 μg/g). The results estimated that the highest mean carbohydrate (13.85±1.26), fats (22.26±1.32), and water content (77.66±0.62%) were found in O. aureus. Otherwise, the largest ash (10.66 ± 1.72%) and protein (65.16±1.27) concentrations were recorded in S. galilaeus. The current study showed that S. galilaeus had the highest activity of antioxidant enzymes in the liver. The present study suggested that the children should intake less than 18.51g/day or 129.62g/week O. niloticus muscle, 13.761g/day or 96.33 g/week O. aureus muscle, and 16.66g/day or 116.66 g/week S. galilaeus muscle. Youth, on the other hand, should consume no more than 49.38g/day or 345.67g/week O. niloticus muscle, 36.69g/day or 256.88g/week O. aureus muscles, and 44.44g/day or 311.11g/week S. galilaeus muscle. Finally, adults should intake fewer than 84.65g of O. niloticus muscle per day or 592.59g per week, 62.90g of O. aureus muscle per day or 440.36g per week, and 47.61g of S. galilaeus muscle per day or 333.33g per week.

Comparative study for bioremediation of cobalt contaminated aqueous solutions by two types of marine macroalgae

Biosorption is an efficient method for removing heavy metals from wastewater. Two dried marine macroalgae species; Ulva fasciata and Colpomenia sinuosa were used for bioremediation of cobalt polluted aqueous solutions. It was established that the optimum biosorption takes place at pH 6.0 and 7.0 for U. fasciata and C. sinuosa, respectively, with contact time 60 min for both species, initial Co(II) concentration 50 and 80 mg/L for U. fasciata and C. sinuosa, respectively, and biomass dosage 0.05 g/50 mL for both species. The biosorption mechanism of Co(II) onto the algal biomass was investigated utilizing the standard techniques. The isotherm models elucidated that Langmuir model fits the experimental data of Co(II) adsorption more than Freundlich model. The maximum biosorption capacity (qmax) obtained for C. sinuosa (62.5 mg/g) was greater than that for U. fasciata (40.0 mg/g). It was also found that the biosorption process using U. fasciata and C. sinuosa followed the second-order kinetic. The effect of calcium, magnesium, and sodium ions (Ca+2, Mg+2, and Na+) on the metal sorption potential by biosorbents was studied. The adsorption behaviour of U. fasciata and C. sinuosa in treating wastewater sample collected from Edku Lake was also investigated.

Is the consumption of Tilapia zillii and Clarias gariepinus from Edku Lake (Egypt) safe for humans: a physiological and biochemical study

The Egyptian government seeks to develop the northern wetlands, including Edku Lake in El Beheira Governorate, to enhance the physiological functions of fish, and thus, improve their quality and promote their products. Therefore, this study was performed on the two cheapest fish species Tilapia zillii and Clarias gariepinus in the Egyptian market, by studying proximate body composition, antioxidant enzyme activity, and bioaccumulation of five trace elements. In this study, T. zillii showed the highest mean of carbohydrates (16.11± 0.67 mg/g), fats (24.21 ± 0.93mg/g), ash (7.33 ±1.00 %), and water content (78.33 ± 1.85 %) whereas, the highest mean of protein content was recorded in C. gariepinus (64.33 ±1.01 mg/g). Antioxidants glutathione reduced level (GSH) (41.66 ± 2. 01 mg/g) and catalase activity (CAT) (21.66 ± 2.6 U/g) demonstrated a significant decrease (p < 0.05) in the liver of C.gariepinus than T. zillii (47.83 ± 3.6 mg/g and 38.16 ± 4.2 U/g, respectively). Concerning trace element concentrations, the highest arsenic (As) concentration was recorded in tissues of C. gariepinus (1.54 ± 0.08 μg/g), whereas, the lowest mercury (Hg) concentration was recorded in the tissues of T.zillii (0.47 ± 0.08 μg/g). The concentrations of mercury (Hg), cadmium (Cd), and lead (Pb) in the two studied fish species exceeded the limits permitted by EOSQC, FAO/WHO, and the EU'. This study recorded that the children should consume less than 16.12857 g/day or 112.90 g/week of T. zillii muscle and 13.27 g/day or 92.92 g/week of C. gariepinus muscle. Moreover, youth should consume less than 43.01 g/day or 301.7g/ week of T. zillii muscle and 35.39714 g/day or 247.78 g/week of C. gariepinus muscle. Finally, adults should consume less than 23.1 g/day and 161.7 g/week of T.zillii muscle, and 61.94286 g/day or 433.6 g/week of C. gariepinus muscle to maintain their safety based on PTWI recommended by FAO/WHO.

Spatiotemporal distribution of some dissolved salts and minerals in Lake Edku connected to Mediterranean Sea: in relation to different pollutant inputs.

Regarding the generally accepted view of the minerals formed in solving the problem of ecosystem pollution, this research aims to track the role of seasonal minerals in overcoming widespread pollution problems in Lake Edku. At eleven locations inside Lake Edku and three locations in the outside the water inlets, some physical and chemical parameters that affect the formation of minerals and salts were detected seasonally. As a result of human activities from 1972 to 2020, the applied remote sensing technology showed a decrease in the area of Edku Lake by 13.3%. The saturation index (SI) of twelve minerals formed in fifty-six seasonal water samples collected from fourteen locations inside and outside the lake was estimated. The saturation index (SI) of anhydrite (ANH), gypsum (GYP), calcium phosphate (CP), magnesium phosphate (MP), calcite (CAL), aragonite (ARG), dolomite (DOL), magnesite (MGS), fluorapatite (FAP), hydroxyapatite (HAP), octacalcium phosphate (OCP), and carbonate-fluorapatite (CFAP) was calculated. The presented SI values of apatite and phosphate minerals including FAP (SI 30.63-65.65), CFAP (SI 28.14-40.02), HAP (SI 24.83-31.81), Ca3(PO4)2 (SI 23.99-25.95), OCP (SI 19.96-25.47), and Mg3(PO4)2 (SI 15.80-17.46) were high. Palmer-Roger's diagram and piper ternary diagram models reflected the abundance of NaCl in lake water with 30, 40, 46, and 75% in winter, spring, summer, and autumn, respectively. Using correlation matrix, multiple stepwise regression and cluster analysis for statistical analysis, the relationship between sedimentary minerals and outflow and drainage, as well as the role of sedimentary minerals in reducing pollution in the lake area, was outlined.

Assessing heavy metal pollution hazard in sediments of Lake Mariout, Egypt

The Cd, Cr, Cu, Ni, and Pb concentrations in the sediments of Lake Mariout were measured and estimated by statistical approaches using the contamination factor (CF), pollution load index (PLI), geo-accumulation index (Igeo), Nemerow index (Iin), ecological hazard index, and potential ecological hazard index (RI). The aim of the present work was to assess the current situation of Lake Mariout compared with other Egyptian lakes regarding heavy metal pollution in the sediment and to identify the putative sources. The measured concentration levels of heavy metals in Lake Mariout sediments were higher than the geochemical background reference condition by a factor of two to three, except for sediment sampled near the Umoum drain, where metal concentrations were close to the geochemical background reference condition. The PLI ranged from moderately to heavily polluted classes. The Igeo ranged from uncontaminated to moderately contaminated classes, where the RI indicates a low hazard. The comparison of Lake Mariout with other lakes indicates that all heavy metal concentrations except for Cd in Lake Mariout were higher than the average concentrations in Edku Lake. However, the average concentrations of Cd and Ni in Burullus Lake were higher than those found in the current study. For Manzala Lake, the Cd, Cu, and Pb concentrations were higher than the measured concentrations in Lake Mariout. The environmental hazard assessments of heavy metal concentrations in the Lake Mariout sediment determined the prevalence of possible anthropogenic pollution sources near the East and West Wastewater Treatment Plants and the El-Max pumping station.

Prediction of future situation of land use/cover change and modeling sensitivity to pollution in Edku Lake, Egypt based on geospatial analyses

Assessing land use/cover (LULC) change in coastal lakes is an essential process for sustainable development. Edku Lake is one of the most important lakes in the northern part of Nile Delta in Egypt. It is directly subject to severe anthropogenic activities. The main objectives of this work were to predict LULC changes within Edku Lake area and to develop a pollution sensitivity model using remote sensing data and modern geographical information system (GIS) techniques. Three Landsat images were acquired in 2000, 2011 and 2018. These images were preprocessed, geo-referenced and prepared for further supervised classification using the maximum likelihood classifier. Five LULC classes were found in the area (water, vegetation, urban, bare and fish farm). CA–Markov model was applied to predict LULC changes using IDRISI software between each two consequent years. A predicted LULC map was obtained for 2025. This map can provide suggestions for future urban and vegetative planning in the studied area. This area was subject to severe changes from 2000 to 2018. Fish farms were significantly increased during this period. The predicted LULC map for 2025 indicates that large vegetative areas will be converted into urban and fish farms. The pollution sensitivity model showed that the eastern parts of the lake are more sensitive to pollution compared with the rest of the lake. Accordingly, protection of biodiversity in Edku Lake can be achieved based on future scenarios and measuring sensitivity of environmental factors and surrounding activities.

Physical, Chemical Properties Assessment and accumulation of Some Heavy Metals in Sediment of Edku Lake, Egypt

Physical, Chemical Properties Assessment and accumulation of Some Heavy Metals in Sediment of Edku Lake, Egypt

Bioaccumulation of Pesticides in Aquatic System of Edku Lake, Egypt: An Approach for Risk Associated With Fish Consumption

Monitoring of some organochlorines (OCs) and organophosphorus (OP) pesticide residues in Edku Lake during 2015-2016 have been determined in water, sediment and Tilapia fish to find out the extent of pesticides contamination and bioaccumulation into the lake. Pesticide residues were determined using gas chromatography equipped with appropriate detectors. The mean residues of ∑BHC, ∑DDT, total OCs, and OPs in water samples were 68.43, 14.17, 118.3 and 138.46 ppb, respectively. The corresponding residues in sediments were 8343.26, 5307.59, 21402.83 and 267.66 ppb, respectively. In fish muscles, the mean residues of ∑BHC, ∑DDT, methoxychlor and total OCs were 2513.56, 1916.85, 46175.05, and 57592.40 ppb, respectively. The corresponding values in fish gills were 3565.44, 16014.96, 13182.44, 35645.15 and 3318.10 ppb, respectively. Sum of BHC and DDT were the mostly detected in muscle samples accounting for 1593.60 and 916.53 ppb, respectively. Regarding bioaccumulation of examined pesticides, bioconcentration factor (BCF) was estimated to be in range 7.96-40701.50 for water/muscle ratio of OCs. In case of BCF for water/gills, the values ranged from 16.72 to 237090.17. BCF values obtained from ratio sediment/muscle or sediment/gills not exceeded than 100. These concepts indicate that OCs induced bioaccumulation in fish tissues may attributed to predicted risks associated with this kind of consumption. All findings represent concept that, Edku Lake represents reservoir of all pollutants coming from north governorates e.g. El-Behira.

Conceptual Merge of Ecohydrologic Watershed and Sponge City Techniques for Managed Sustainability and Strengthened Adaptive Capacity of Nile Delta Coastal Lakes, Egypt

Nile Delta coastal zone in Egypt has special socioeconomic and environmental importance, with internationally acknowledged wetland systems. However, sustainability and adaptive capacity are compromised with progressive developments. Coastal lakes serve basins with intermixed industrial, urbanized and agricultural activities, which require an integrative approach for strengthened adaptivity and sustainability management. This research study presents an innovative management plan that conceptually merges the EcoHydrology approach with the recently initiated Sponge City approach. Principles of both approaches are reviewed to select components that are applicable and practically approved in the Egyptian conditions and evolving changes in the study area of Edku coastal lake. With an analysis of regional activities as well as the use of remote sensing techniques, the study first establishes a base insight into the historic spatiotemporal alterations in Edku lake and its served basin. Then, the climate change impact is incorporated by water balance-related factors to consider potential flood and/or drought risks in the adaptation plan. The study presents preliminary results with System Dynamics (SD) simulations. Various scenarios have been examined using VensimPLE×32-based SD modeling. The scenarios covered alternate combinations of the proposed measures. Optimal 25-year managerial EcoHydro-Spongic Strategy is found with gradual application of Sponge City measures to prevent 30% of wastewater discharges, while Ecohydrology measures are projected to reduce 60% of pollutant loads into Edku lake from agricultural lands. Further 10% of pollution reduction is achievable with applied phyto-technology within the Lake

Multi Criteria Framework for Surface Water Quality Management

Edku Lake, the third largest in the system of the northern coastal wetlands in Egypt, situated on the west part of Nile Delta, is considered as an important fishing area in Egypt. The lake suffers from high levels of aquatic vegetation and from the expansion in fish farming and agricultural discharges. To solve lake water quality problems, the study aims to develop the multi-criteria analysis (MCA) framework capable of evaluating the proposed lake water quality improvement scenarios. The work tasks were divided into two phases. In the first phase, many proposed scenarios involved on primary, secondary, surface wetland, biological biofilm, and adding a new artificial inlet were proposed by applying Surface-water Modeling System (SMS) with two dimensional hydrodynamic. The second phase involved in developing the required hierarchical MCA based on an integrated technical, environmental, economic and socio-community indicators. The main results of MCA showed that the water quality management scenario focusing on combination of applying biological biofilm technique for drain effluents and also adding a new artificial inlet at the northern lake region can represent the optimum scenario for solving the lake water quality problems.

Water Quality and Bacterial Load of Water and Tilapia Organs from Edku Lake

Water Quality and Bacterial Load of Water and Tilapia Organs from Edku Lake

Diatom analysis of Edku Lake sediments to assess the Late Holocene environmental changes in northern Egypt

Quantitative and qualitative diatom analyses from the Edku Lake core sediments were used to assess the environmentalhistory of the lake during the Late Holocene. A total of 128 diatom species and varieties were identified from 118 samplesrepresenting of four short cores obtained from the lake. The topmost samples represent the recent time are dominant by diatom taxathan that recorded in the lowered cores samples. Detailed diatom investigation indicated a considerable variation in the compositionand distribution of the diatom taxa among the studied cores. The non-planktonic epiphytic taxa Cocconeis placentula, Epithemiasorex, Epithemia adnata and the benthic forms Navicula aegyptiaca, Campylodiscus biocostatus and Campylodiscus clypeus werethe most dominant species in the core sediments, which mainly reflect slightly brackish, alkaline, eutrophic shallow lake conditionduring the time of deposition. Multivariate statistical analysis included hierarchical ascending clustering and Detrendedcorrespondence analyses were used to identify ecological groups of diatoms. The results distinguished six ecological groups thatreflect changes in the water quality, water salinity, lake-level, pH and eutrophication of the lake, which in turn may related toclimatic changes and anthropogenic impacts.

Sustainability of Water Bodies of Edku Lake, Northwest of Nile Delta, Egypt: RS/GIS Approach

In this paper, Edku Lake was selected as a case study to apply the RS/GIS techniques to investigate the water body sustainability. It is one of the northern coastal lakes in Egypt, located at the northwestern part of the Nile Delta. Edku Lake is an important fishing area in Egypt and receives its water from two sources. One of sources is the drainage water of Kom Belag and Bersik drains and second is the sea water. Remote sensing and GIS software are used in this study for processing of the images and managing the database of each image. The different techniques of classification were tested, the results showed that the maximum likelihood supervised classification technique was more accurate to monitor changes in the water bodies of the Lake. The technique was applied to subsets of the Landsat TM, ETM+ and OLI/TIRS images acquired on 1984, 1990, 1998, 2003 and 2015, respectively to monitor changes in the Lake. The results showed that the water bodies of the lake decreased during the period from 1984 to 2015. The extracted data from the images have been used to develop statistical models for the different classes to predict the future situation of each class. The results of prediction indicated that the water body of the lake will be more decrease in 2030. The results indicate that the water body of the lake is not sustainable. The results of this study will act as warning for the decision makers to take the necessary actions/policy to reduce the environmental risk and maintain the healthy environment of the lake.

Evaluation the Effect of Local and Imported Yeasts as Supplementary Food on the African Catfish (Clarias gariepinus) in Egypt

This study aims to evaluate the effect of different graded levels of local and imported yeast (Saccharomyces cerevisiae) on the growth performance of African catfish, Clarias gariepinus. 250 fingerlings of the African catfish were collected from Edku Lake (northern Egypt) to carry out an experimental study. After a two-week acclimation period, the fish were divided into 5 groups of 50 fish each. Then, each group of fish was randomly distributed into aerated rectangular fiber glass tanks (0.90 x 3.70 x 1.90 m). The tanks were filled with tap water in which oxygen saturation was 5.6 g/l at pH 7.9; water temperature range from 26 to 27°C; and, photoperiod was 12:12 Light: Dark. The results showed that the supplementation of local yeast, Saccharomyces cerevisiae, improved growth and feed utilization. Significant results were recorded for treatment group 2 (G2) that fed on commercial pellets diet with 2% local Baker Yeast compared to the control group. It was shown that the yeast supplementation significantly affected the whole-fish body composition (Feed intake-dry matter, protein intake and energy intake). All treatments exhibited higher values compared to the control group. It was suggested that the positive effect of live yeast in African catfish diets under the present study conditions may be due the release of growth factors at the selected yeast concentration. In this study treatment of G2 that fed on commercial pellets diet with 2% local Baker Yeast showed the lowest values for dray matter, ether extract and ash content, while it showed highest value for crude protein compared to the control group. Hematological analysis of all the treatment groups showed satisfactory values compared to the control groups. From the economic point of view similar to the imported yeast, the use of cheap local baker's yeast for African catfish also increases their growth and production under farming conditions.

Evaluation on the effect of local and imported yeast as supplementary feed on African catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt; Burchell, 1822) in Egypt

This study aims to evaluate the effect of different graded levels of local and imported yeast ( Saccharomyces cerevisiae ) on growth performance of African catfish, Clarias gariepinus . A total of 250 fingerlings of the African catfish Clarias gariepnus were collected from Edku Lake for the experiment. The fish were divided into 5 groups, containing of 50 fish in each group. Describe the group and treatment given to each group of the fish. The results showed that the supplementation of local yeast, improved the growth and feed utilization. Significant results were recorded for treatment of G2 compared to the G1. It was shown that the yeast supplementation significantly affected the whole-fish body composition. All treatments exhibited higher values compared to the G1. Treatment of G2 also showed the lowest values for dray matter, ether extract and ash content, while it showed highest value for crude protein compared to the G1. Hematological analysis of all the treatments showed satisfactory values compared to the G1. From the economic point of view, the utilization of local baker's yeast for African catfish could reduce the cost, while increases the growth and production performance under farming conditions.

Phylogenetic differentiation of wild and cultured Nile tilapia (Oreochromis niloticus) populations based on phenotype and genotype analysis

Variation in phenotype based on morphometric character indices and meristic counts and in genotype based on random amplified polymorphic DNA (RAPD) fingerprinting among different wild and cultured Nile tilapia (Oreochromis niloticus ) populations were analyzed phylogenetically to study and compare the amount of differences in phenotype with the amount of differences in genotype and to help assess the degree of phenotypic plasticity shown by these populations. The results revealed that there were significant differences (P≤0.05) in most of morphometric character indices and meristic counts among different wild and cultured Nile tilapia populations tested. Data of genetic similarity coefficients among four populations of Nile tilapia based on RAPD data of all primers used, showed the highest interpopulation genetic similarity (64%) exhibited between Manzalah and Edku Lake populations, while the lowest genetic similarity (37%) was recorded between Manzalah Lake and cultured populations. The hierarchical cluster analysis based on each phenotype and genotype analysis grouped the four populations into two major category groups: Edku Lake, Manzalah Lake and Nile river populations group and cultured population group. Within these major grouping, wild Nile tilapia were grouped close together. Also, Edku Lake population appears to be more similar to that of Manzalah Lake population than that of Nile river population. Moreover, the great concordance between each phylogeny based on phenotype and genotype analysis revealed that the phenotypic plasticity may not be found in the different Nile tilapia populations tested and the relationship among them considered as intraspecific.

Flesh quality differentiation of wild and cultured Nile tilapia (Oreochromis niloticus) populations

Variation in chemical composition and carcass traits among different wild and cultured Nile tilapia, Oreochromis niloticus populations were analyzed to study and compare the differences among different wild (Manzalah lake, Nile river and Edku lake) and cultured Nile tilapia populations. Data of body composition of different Nile tilapia ( O. niloticus ) populations showed that, the highest mean value of moisture content (80.32 ± 0.39%) was shown by cultured population and differ significantly (P≤0.05) from those of other populations studied. The highest mean value of protein content (58.14 ± 0.51%) was shown by cultured population but did not differ significantly (P≤0.05) from that of River Nile population. Lipids content showed lower mean (21.74 ± 0.06%) by River Nile population but did not differ significantly (P≤0.05) from that of cultured population. The results of carcass traits show insignificant differences (P≤0.05) in all parameters among different Nile tilapia populations studied. The evaluation of flesh quality of different wild and cultured populations of Nile tilapia studied can result in a genotype suitable for aquaculture. Key words : Flesh quality, wild, cultured, Nile tilapia, population.