Lake Manzala Research Articles

Characterization of 28S rRNA sequences of cestoda parasite Electrotaenia malapteruri Fritsch, 1886 from the Electric catfish Malapterurus electricus (Siluriformes: Malapteruridae)

Proteocephalids are cestoda parasites that mostly infect freshwater fish. The present study was carried out to investigate the presence of proteocephalids infecting the electric catfish Malapterurus electricus from Lake Manzala, Kafr El-Sheikh Governorate, Egypt. Morphological characterization revealed the present parasite is a cestoda belonging to the genus Electrotaenia. Morphologically, the recovered worms were characterized by an elongated body measuring 100–127 (120 ± 2) mm long and 0.92–2.11 (2.76 ± 0.1) mm wide. The anterior part of the worm was obvious terminated at a spherical scolex measured 1.12–1.91 (1.72 ± 0.01) mm long and 1.12–1.65 (1.42 ± 0.01) mm wide with a rostellum-like apical organ equipped by 5–6 irregular rows of minute hooklets, as well as four uniloculate suckers with a diameter of 0.13–0.15 (0.14 ± 0.01) mm and covered with microtriches. A long unsegmented neck was observed followed by acraspedote and anapolytic strobila consisted of 85–120 proglottids divided into 50–58 immature, 12–19 mature, and up to 49 gravid proglottids. Molecular characterization based on 28S rRNA sequences was done to confirm the taxonomy of this parasite based on its morphology. It was observed that there was a close identity up to 72.0% with other protocephalid species obtained for comparison from the GenBank. Also, the data obtained revealed that there was high blast scores and low divergence between the present parasite and previously described Electrotaenia malapteruri (acc. no. JX477434). Phylogenetic analysis showed that the parasite sequence in conjunction with existing data investigates the placement of this protocephalid species within Proteocephalidea. It was shown that the present species is deeply embedded in the genus Electrotaenia with close relationships to other Electrotaenia malapteruri as a putative sister taxon.

Assessment and ecological indicators of total and polycyclic aromatic hydrocarbons in the aquatic environment of lake Manzala, Egypt

ABSTRACTThe study objective was to assess the profile of aliphatic and polycyclic aromatic hydrocarbons in the aquatic environment of Lake Manzala and to determine the potential sources and effects of these hydrocarbons. To reach these objectives 24 surface sediment and 24 tilapia fish were collected and analyzed using GC-FID and GC-MS. The highest concentrations for n-alkanes (∑n-C15–35) (19,625 ng g−1) and PAHs (∑45PAHs) (5,153 ng g−1) were found in sediments collected from Bahr Al-Baqar drain while Al-Temsah and Al-Hamra sites contained the lowest concentrations. Different diagnostic molecular ratios for hydrocarbons were used to evaluate sources of the hydrocarbons. The hydrocarbons were found to have differing proportions of petrogenic, pyrogenic, and biogenic sources. Comparison to sediment quality guidelines indicated PAHs were below the effect range low (ERL) with the exception of acenaphthene, fluorine, and ∑45PAHs in Bahr Al-Baqar drain sediments. Tissue samples had moderate PAH concentrations for ∑45PAHs ranging from 302.5 ng g−1 West of Bashteer (S3) to 596 ng g−1 in Legam (S5). Since fish metabolize PAH quickly, their detection suggest continual or very recent exposure. The PAH in sediment and fish from Lake Manzala are at a low or below level of environmental concern.

Forecasting future changes in Manzala Lake surface area by considering variations in land use and land cover using remote sensing approach

This study assesses the changes in surface area of Manzala Lake, the largest coastal lake in Egypt, with respect to changes in land use and land cover based on a multi-temporal classification process. A regression model is provided to predict the temporal changes in the different detected classes and to assess the sustainability of the lake waterbody. Remote sensing is an effective method for detecting the impact of anthropogenic activities on the surface area of a lagoon such as Manzala Lake. The techniques used in this study include unsupervised classification, Mahalanobis distance supervised classification, minimum distance supervised classification, maximum likelihood supervised classification, and normalized difference water index. Data extracted from satellite images are used to predict the future temporal change in each class, using a statistical regression model and considering calibration, validation, and prediction phases. It was found that the maximum likelihood classification technique has the highest overall accuracy of 93.33%. This technique is selected to observe the changes in the surface area of the lake for the period from 1984 to 2015. Study results show that the waterbody surface area of the lake declined by 46% and the area of floating vegetation, islands, and land agriculture increased by 153.52, 42.86, and 42.35% respectively during the study period. Linear regression model prediction indicates that the waterbody surface area of the lake will decrease by 25.24% during the period from 2015 to 2030, which reflects the negative impact of human activities on lake sustainability represented by a severe reduction of the waterbody area.

Lake Manzala Egypt, a bibliography: II-Microbiological studies

This bibliography was compiled in order to facilitate location of available literature concerning the microbiological studies on Lake Manzala, Egypt.

Two variable residence time-based models for removal of total phosphorus and ammonium in free-water surface wetlands

This paper presents two powerful and productive models, called VART-TP model and VART-NH4 model, for simulating the removal processes of total phosphorus (TP) and ammonium (NH4+), respectively, in constructed wetlands with free water surface (FWS). A distinctive feature of the models is the incorporation of a dynamic diffusion-dominated root-zone. The VART-TP model was tested with data collected from four small test cells of constructed wetlands (TCW) planted with submerged aquatic vegetations in south Florida, USA. The test cells were divided into two groups with the north test cells (N1 & N15) receiving an average phosphorus (TP) concentration of 71μg/l and the south test cells receiving an average TP concentration of 27μg/l. Testing results showed that root mean square error (RMSE) of the VART-TP model varied in the range of 4.45-17.50μg TP/l., respectively, for north test cells while the RMSE ranged between 3.58-7.63μg TP/l for south test cells. The result suggested that (1) the N1 and N15 test cells receiving high TP concentrations are capable of removing TP with high efficiency and (2) the VART-TP model is capable of simulating the removal processes of TP. The VART-NH4 model was tested with data collected from Lake Manzala Engineered Wetland (LMEW), Egypt, which generally received the influent of high ammonia concentration (average=2.26mg NH4/l). The testing results showed that the NH4+ concentrations simulated with the VART-NH4 model were in reasonable agreement with those monitored at the wetland outlet, as indicated with the RMSE of 0.06mg/l. The results demonstrated that the VART-TP and VART-NH4 models are reliable and efficient modeling tools for designing constructed wetlands.

Seasonal Variations in Soil and Bacteriological Properties as Affected by Phytogenic Mounds (Nebkhas) of Halocnemum strobilaceum in Lake Manzala, Egypt

P HYTOGENIC mounds (nebkhas) formed by halophytes are widely distributed in coastal and desert environments. Such nebkhas provide loci for geochemical and biological activities that influence ecosystem processes and function. Seasonal variation in soil and bacterial properties were investigated within the nebkhas under the canopy of Halocnemum strobilaceum and in the surrounding unvegetated sites at salt marshes of Lake Manzala. The parameters measured include soil moisture, organic matter, total nitrogen and phosphorus, pH, electrical conductivity (EC), and bacterial community and enzyme characteristics. Enrichment ratios for soil salinity and nutrients were evaluated to indicate the salinity and fertility islands within nebkhas. Soil moisture content showed significant differences between the different seasons with the highest value in winter (16.55%) at unvegetated control site.Soil electrical conductivity, total nitrogen and phosphorus had their significantly higher values in nebkhas during autumn. The enrichment values for the measured soil parameters ranged from 0.31 to 4.09 in the four seasons which indicates a clear accumulation effect for soil nutrients and salts within the nebkhas under the canopy of H. strobilaceum. Bacterial abundance was consistently higher in nebkhas through all seasons. Eleven genera of bacteria belong to Firmicutes, Actinobacteria and proteobacteria phyla were recorded in nebkha and unvegetated sites. These genera varied in their occurrence between the two locations and the four seasons. It can be concluded that the formation of nebkhas by halophytic vegetation have noticeable effects on accumulation of soil salinity and fertility during different seasons that affect bacterial abundance and activity in coastal environment.

Physicochemical properties of Manzala Lake, Egypt

Physicochemical parameters such as temperature, total dissolved solid (TDS), pH, salinity, dissolved oxygen (DO), biological oxygen demand (BOD), permanganate index (PI), chloride and nutrient salts were measured in water samples, collected from 12 sites of Manzala Lake during winter and summer, 2015. A lot of fluctuations were observed in these parameters affected by the poor connection of water body of the lake and the diversity of the incoming flows. The pH values of water were alkaline throughout the lake and closely correlated with widely varied salinity and DO values. BOD increases in the south eastern-located sites affected mostly by Bahr El Baqur drain effluents especially during winter during the scheduled water block. PI was highly influenced by the agricultural and domestic waste effluents. Nutrients salts ranged between 5.47-249, 2.61-15.1, 0.64-24.5, and 3.47-22.9 µmol L-1 for ammonia, nitrite, nitrate and phosphate, respectively. N/P ratios (2.28-12.8) in the present study indicated that nitrogen is the limiting factor for phytoplankton fluorination except for some sites in the south eastern region. The levels of total polycyclic aromatic hydrocarbons were found affected by the seawater inflows during winter. It can be concluded from obtained data that the south eastern region showed worst water quality parameters.

Some heavy metal contents in surface water and sediment as a pollution index of El- Manzala Lake, Egypt

Some heavy metal contents in surface water and sediment as a pollution index of El- Manzala Lake, Egypt

Distribution and residue profile of organochlorine pesticides and polychlorinated biphenyls in sediment and fish of Lake Manzala, Egypt.

Distributions of OCPs and PCBs in sediment and tilapia from Lake Manzala were investigated. Chlorpyrifos, ∑DDT, and HCB sediment concentrations were spatially variable and relatively elevated. ∑96PCBs, ∑DDT, and 4,4'-DDE exceeded the Effects Range Low in 88, 75, and 42% of the sediments, respectively. The major input from Cairo, the Bahr Al-Baqar drain, exceeded the Probable Effects Level for DDT isomers in sediments. OCP and PCB concentrations in tilapia were below action and tolerance levels set by the US-EPA.

Geochemical Assessment of Pollution at Manzala Lake, Egypt: Special Mention to Environmental and Health Effects of Arsenic, Selenium, Tin and Antimony

Geochemical Assessment of Pollution at Manzala Lake, Egypt: Special Mention to Environmental and Health Effects of Arsenic, Selenium, Tin and Antimony

Environmental Damage Caused by Wastewater Discharge into the Lake Manzala in Egypt

Lake Manzala is a brackish lake in northeastern Egypt on the Nile Delta. It is the largest of the northern Delta lakes of Egypt. The Lake is exposed to high inputs of pollutants from industrial, domestic, and agricultural sources. Climate gases and large amounts of particulate matter, nutrients, bacteria, heavy metals, and toxic organics are transported to the Lake through the wastewater discharge. Water samples were collected and subjected to physicochemical analysis and microbiological study. Results have shown great changes in physical and chemical properties of water including: temperature (13.5°C in winter -32°C in summer), pH (7.8-9.2), dissolved oxygen (2.5-12.8 mgl-1), total dissolved solids (1033-43406 mgl-1), total suspended solids (120-387 mgl-1), ammonia (2.5-32.3 mgl-1), nitrite (0-0.076 mgl-1), nitrate (0.01-7.88 mgl-1), phosphate (0.26-2.37 mgl-1), Fe (0.01-0.63 mgl-1), Zn (0-0.35 mgl-1), Cu (0.01-0.91 mgl-1), Cn (0.002-0.029 mgl-1) and Ni (0-0.002 mgl-1). Results, also, showed a quit great density of total viable bacterial count and indicator organisms including total Coli forms, fecal coli forms, Aeromonas spp., Staphylococcus spp. and Vibrio spp. It is concluded that water in Lake Manzala is highly damaged and the phenomena need more attention in order to reduce the pollution load that reaches the Mediterranean Sea.

Screening of Bacterial and Fungal Biota Associated with Oreochromis niloticus in Lake Manzala and Its Impact on Human Health

In this study fish samples were investigated for Bacteria and Fungi, in fish parts, such as intestine, gills and skin. Bacterial counts of Total viable bacteria (T.V.B) reached more than 9.5 × 105 cfu and faecal coliforms (F.C) reached 1.2 × 105 cfu. Different species were identified, Using API technology. Escherichia coli comes first by being recording thirty number case of isolation constituting 36%, it followed by Proteus mirabilis which is represented by twenty four number case of isolation accounting for 30%. Other taxa viz: Klebsiella pneumonia, Citrobacter freundii, Providencia stuartii and Erwinia sp. came next according to their case number of isolation, they represented only by 7%. They showed different antibiotics with different inhibitory concentrations, resistance pattern to gentamycin 10 μg, Penicillin G, tetracycline 30 μg, Ampicillin 10 μg, Ampicillin 30 μg, chloramphenicol (C) 30 μg, Rifampicin 25 μg, Streptomycin 5 μg, cefotaxime 15 μg. Mycological investigation revealed the presence of variety of fungal species, particularly, toxigenic species, such as, Aspergillus spp, Penicillium spp and Fusarium spp. These results are indication of the spoilage of fishes which caught from Lake Manzala and are risky for human consumption and hazardous to human health in this important area of Egypt, due to the high pollution condition of Lake Manzala.

الهيئة العامة لتنمية الثروة السمکية وأثرها علي بحيرة المنزلة وعموم المسطحات المائية

الهيئة العامة لتنمية الثروة السمکية ، هي إحدى الجهات المتخصصة وأنشأت بالقرار رقم190 لسنة 1983وتختص بالدراسات العلمية والإشراف علي کافة المقرات المائية في عموم مصر من بحار وأنهار وبحيرات، ومنهم بحيرة المنزلة ، والتي تقع في شمال شرق الدلتا وسواحلها تطل علي محافظات عديدة ،دمياط، بورسعيد، الدقهلية ، الشرقية وهي أکبر البحيرات المصرية ، وتخضع بحيرة المنزلة في إدارتها للهيئة العامة لتنمية الثروة السمکية ، وهذه الهيئة تتبع وزارة الزراعة. مقر الهيئة مدينة القاهرة ويتبعها إدارات مختلفة في مواقع تلک البحيرات أو قريبة منها ، لتمکن إدارة الهيئة من التواصل والإشراف وتنفيذ المهام حسب خطة الهيئة لتحقيق أهدافها المرجوة في تنمية وتطوير الثروة السمکية في مختلف المسطحات المائية التي تتبعها بمساعدة مختص في الثروة السمکية والأحياء البحرية وکل ما هو مطلوب لتنفيذ مهام وخطة الهيئة المرسومة والمقررة وفي هذا الفصل المقدم کتب عن الهيئة ودورها وسياستها مع الترکيز علي أثر الهيئة وتقيم عملها علي مسطح بحيرة المنزلة ، وبقدر الإمکان تقييم دور وأثر الهيئة علي باقي المسطحات المائية في عموم مصر . The General Authority for the Development of Fish Wealth is one of the specialized bodies established by Decree No. 190 of 1983, which is concerned with the scientific studies and supervision of all water stations throughout Egypt from seafarers, rivers and lakes, including Manzala Lake, which is located in the northeast of the delta and its coasts. Dakahlia, the largest Egyptian lakes, and Lake Manzala under the management of the General Authority for the development of fish wealth, and this body follows the Ministry of Agriculture. The Authority's headquarters is located in the city of Cairo and is followed by different departments in the locations of these lakes or nearby, to enable the Authority's administration to communicate, supervise and carry out the tasks according to the Commission's plan to achieve its desired objectives in developing and developing the fish resources in the different water bodies followed by the assistance of a specialist in fisheries and marine life, In this chapter, he wrote about the Commission, its role and policy, focusing on the impact of the Commission and evaluating its work on the Manzala Lake, and to the extent possible assess the role and impact of the Commission on the rest of the water bodies throughout Egypt.

Effects of Salinity on Some Haematological and Biochemical Parameters in Nile Tilapia, <i>Oreochromus niloticus</i>

Any change in haematological and biochemical parameters could be a predictor of unfavorable environment or effect of different stress factors. The present study was designed to assess different salinity concentration induced changes in some haematological and biochemical parameters in 64 O. niloticus fishes captured from Manzala Lake (Egypt), they were acclimatized and fed with commercial fish diet for one week before starting the experiment for another 2 weeks. Fishes were divided into 4 equal groups assigned as; control, 4g NaCl\L, 8 g NaCl\L and 12 g NaCl\L. RBCs, HCT, Hb concentration, platelets count, superoxide dismutase activity, catalase activity, potassium level and serum total protein were estimated. The HCT, Hb concentration, platelets count and potassium levels were significantly higher in (4gNaCl\L, 8gNaCl\L and12gNaCl\L, respectively). The Superoxide dismutase activity (SOD), total protein, RBCs and catalase activit were significantly lower in (4gNaCl\L, 8g NaCl\L and 12gNaCl\L, respectively) compared to the control group. Other parameters such as WBCs, haematimetric indices (MCV, MCH, MCHC), malonedialdhyde (MDA) level, carbonyl protein (CP), glutathione reductase (GR) activity, as well as serum sodium, glucose, cortisol and IgM, did not show any significant differences in the estimated salinity concentrations.

DNA Barcoding Identifies a Unique Haplotype of Nile Tilapia <i>Oreochromis niloticus</i> Thriving in Egyptian Freshwater and Brackish Water Lakes

Global shortage of freshwater is expected to reduce aquaculture activities that depend upon freshwaters. Mining the wild genetic resources of fish species can aid much the selection and development of new strains capable of withstanding unusual culturing conditions, such as tolerance to unusual salinities. Nile tilapia is a supreme international aquaculture species, with a limited degree of tolerance to brackish waters. In the current study, DNA barcoding for the Nile Tilapia Oreochromis niloticus , using the mitochondrial cytochrome oxidase subunit I gene, was carried out. Samples were collected from two locations at Manzala Lake in the North of Egypt (El-Serow, salinity 1‰; and Ashtoom El-Gamil, Salinity 20‰); and from Lake Nasser (salinity 1‰;) in the South of Egypt. Numbers, locations and phylogenetic interrelationships among these haplotypes were determined, appending to the comparison the world haplotypes available in GenBank database. The results indicated the main haplotype lineages in the area of study and the world. Also, a newly identified haplotype with natural tolerance to different salinities could be identified from both studied lakes. This can contribute much to the genetic enhancement of tilapia aquaculture using new parents with more capability to tolerate salinity differences, producing then pure or hybrid offsprings with further ameliorated salinity tolerance.

Morphological re-description of Electrotaenia malapteruri (Cestoda: Proteocephalidae) and Dujardinnascaris malapteruri (Nematoda: Heterocheilidae) infecting the Electric catfish Malapterurus electricus and heavy metal accumulation in host and parasites in relation to water and sediment analysis in Lake Manzala, North Delta, Egypt.

Parasites are one of the most serious limiting factors in aquaculture. The Electric catfish Malapterurus electricus was subjected to study the prevalence and mean intensity of parasitic infections throughout the whole year of 2015. Heavy metals accumulation in host fish and parasites were determined in relation to water quality and sediments of two different sites of Lake Manzala (Manzala and Bahr El-Baqar), Egypt. A total of 100 specimens of Electric catfish were collected and examined for the presence of helminth parasites. Two parasite species were recovered and morphologically identified. These were cestoda Electrotaenia malapteruri and nematode Dujardinnascaris malapteruri. Heavy metal analysis in water and sediments showed that measured heavy metals in Bahr El-Baqar were found in risky levels higher than permissible limits and Manzala site. Sediments were found to contain a higher level of metals than water samples. Heavy metals accumulation in recovered parasites and their host were also determined and showed significantly higher concentrations in parasites compared to their host tissues. According to bioconcentration factors, E. malapteruri showed that highest accumulation rate for all recorded elements up to 302. Essential elements like Cu and Fe were found in significantly higher concentrations in D. malapteruri, whereas E. malapteruri accumulated elements Cd, Pb, Ni, Mn, Zn and Ca to a significantly higher degree. Accordingly, the ratios (C[D.malapteruri]/C[E. malapteruri]) for most essential elements were higher than 0.5. Therefore, fish cestodes can be regarded as useful bio-indicators more than nematodes when evaluating the environmental pollution of aquatic ecosystems by heavy metals.

Assessment of radon level in soil samples from Manzala Lake East Nile Delta, Egypt using passive technique

<p class="abstract"><strong>Background:</strong> Radon is an important natural radioactive factor harmfully, because radon is radioactive gas comes from the natural decay of uranium series deposits in soil, which is harmful on human and environment.</p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">The radon concentrations and exhalation rate were measured using passive technique with CR-39 and LR-115 detectors in twenty soil samples from and around Manzala Lake in the North Nile Delta, Egypt. </span><span lang="EN-IN"> </span></p><p class="abstract"><strong>Results:</strong> From the results the average value of radon concentration ranged from 874.51 to 136.99 Bqm<sup>-3</sup>.</p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">The present study can be used as reference information to detect any harmful radiation that would affect the human and assess any changes in the radioactive background in the studied area. </span></p>

Hydrodynamic and water quality modeling of Lake Manzala (Egypt) under data scarcity

Egyptian coastal lakes represent about 25 % of the Mediterranean total wetlands. Four of the coastal lakes are located north of the Nile Delta and are known as the Northern Delta Lakes. They are severely environmentally degraded and are considered vulnerable to the impacts of climate change, in particular the expected sea level rise. Lake Manzala lies on the eastern north coast of Egypt and is considered as the largest Egyptian coastal lake. Economically, Lake Manzala is considered as one of the most valuable fish sources in Egypt. The water quality status of the lake has been degraded due to the progressive increase in industrial, municipal, and agricultural wastewater discharge. In this work, a hydrodynamic and water quality model for Lake Manzala was developed, under the limitation of hydrological data, which prevented model validation, using MIKE21 modeling system. The proposed model was calibrated with observed data for 1 year (August 2010–July 2011). Typical records at five stations for water levels were used, while the water quality data were collected from 11 field stations. The model results show good agreement with the observed water depth, water temperature, and salinity records. The values of average absolute error, for all stations, were about 0.06 m and 0.56 °C for water depth and water temperature, respectively. In the following, the calibrated model is going to be used to investigate the impacts of future climatic changes on hydrodynamic and water quality characteristics of the lake. Moreover, this developed model will be used as a management tool to examine different enhancement water quality scenarios for the lake.

Determination of Some Heavy Metals in water of the Southern Region of Lake Manzala, Egypt

Determination of Some Heavy Metals in water of the Southern Region of Lake Manzala, Egypt

Data-driven modeling for water quality prediction case study: The drains system associated with Manzala Lake, Egypt

Abstract Manzala Lake, the largest of the Egyptian lakes, is affected qualitatively and quantitatively by drainage water that flows into the lake. This study investigated the capabilities of adaptive neuro-fuzzy inference system (ANFIS) to predict water quality parameters of drains associated with Manzala Lake, with emphasis on total phosphorus and total nitrogen. A combination of data sets was considered as input data for ANFIS models, including discharge, pH, total suspended solids, electrical conductivity, total dissolved solids, water temperature, dissolved oxygen and turbidity. The models were calibrated and validated against the measured data for the period from year 2001 to 2010. The performance of the models was measured using various prediction skill criteria. Results show that ANFIS models are capable of simulating the water quality parameters and provided reliable prediction of total phosphorus and total nitrogen, thus suggesting the suitability of the proposed model as a tool for onsite water quality evaluation.