Lake Qaroun Research Articles

Dietary Supplementation Impacts of Potential Non-pathogenic Isolates on Growth Performance, Hematological Parameters and Disease Resistance in Nile Tilapia (Oreochromis Niloticus)

Pseudomonas fluorescens biovars were isolated from Oreochromis niloticus collected from Qaroun Lake fish farms, Egypt. Microorganisms were added to basal diet with 30 % protein to assess their probiotic properties on growth-performance, hematological parameters, enzymatic activities and survival rate. Tilapia (2.93 ± 0.22 g) were distributed into four equal groups, three replicates each. First group were fed on basal diet as control group, 2 nd , 3 rd and 4 th groups were fed on diet supplemented with Pseudomonas fluorescens biovar I, II & III respectively; fish were fed twice daily at the rate of 5-7 % of their body weight for 45 days. The groups were challenged intra-peritoneal with Aeromonas hydrophila (1.8 x 10 8 CFU ml −1 ) and observed for 7 days. The growth rate was significantly higher in groups fed on Pseudomonas fluorescens in the diet than control group. Hematological and non-specific immune parameters were significantly higher than control group. The highest protein, globulin, glucose, Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenases activity were observed at 3 rd group which fed on Pseudomonas fluorescens biovar II. The challenged fish exhibited lowest cumulative mortality rate in 3 rd group (10%) compared to control group (90%). So, it could be concluded that non-pathogenic pseudomonas isolates from marine or brackish water could confer beneficiary effects for Nile tilapia through improving growth performance, immunity enhancement and resistance against diseases.

Risk Assessment and Toxic Effects of Metal Pollution in Two Cultured and Wild Fish Species from Highly Degraded Aquatic Habitats

Lake Qaroun is an inland lake at the lowest part of El-Fayoum depression, Egypt. It receives agricultural and domestic non-treated drainage waters, which are also used for aquaculture in Qaroun area. The results of the present study aimed to provide comparable data between wild (collected from Lake Qaroun) and cultured (collected from Qaroun fish farms and the reference site) Nile tilapia Oreochromis niloticus and mullet Mugil cephalus, as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption. Metal concentrations in fish tissues showed a species-specific bioaccumulation pattern. Statistically significant differences were observed in the mean metal concentrations with lower bioavailability in M. cephalus compared with O. niloticus in internal vital organs (liver, kidney, and muscle) but much higher in external organs (gill and skin). Histopathological alterations and evident damages were observed in gill, liver, and kidney of both species collected from Lake Qaroun and Qaroun fish farms compared with those from the reference site. The results showed significant increase of plasma aspartate aminotransferase and alanine aminotransferase activity as well as creatinine and uric acid concentration in both fish species from polluted locations. The human health hazard index showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for consumer health.

The role of Ni in the surface stability of Cu–Al–Ni ternary alloys in sulfate–chloride solutions

Abstract The stability of Cu–Al–Ni ternary alloys used in the manufacturing of NaCl and Na2SO4 from Lake Qaroun in Egypt was investigated in sulfate–chloride electrolytes. Different electrochemical techniques were used. The results show that the increase in the nickel content improves the stability of the ternary alloys due to formation of a stable barrier film. The barrier film behaves like an ideal capacitor and its stability is affected by the chloride ion concentration. An equivalent circuit model for the electrode/electrolyte interface was proposed and the experimental impedance data were fitted to theoretical data according to this model. The surface morphology and barrier layer constituents were investigated by SEM/EDAX unit.

Genotoxic effects of metal pollution in two fish species, Oreochromis niloticus and Mugil cephalus, from highly degraded aquatic habitats

In Egypt, Lake Qaroun and its neighbouring fish farms are in a serious environmental situation as a result of pollution by agricultural sewage and domestic non-treated discharges. The present study aims to evaluate genotoxic effects of toxic metals in cultured and wild Nile tilapia, Oreochromis niloticus and mullet, Mugil cephalus collected from these contaminated aquatic habitats, in comparison with fish from a non-polluted reference site. Heavy-metal concentrations (Cu2+, Zn2+, Pb2+, Fe2+ and Mn2+) in water and sediment samples were recorded. The condition factor (CF) was taken as a general biomarker of the health of the fish, and genotoxicity assays such as the micronucleus (MN) test and a DNA-fragmentation assay were carried out on the fish species studied. In addition to micronuclei, other nuclear abnormalities (NA) were assessed in fish erythrocytes. Degradation of the studied aquatic habitats revealed species-specific effects. A significant decrease in CF values associated with a significant elevation in MN and NA frequencies was observed in fish collected from the polluted areas compared with those from the reference site. Moreover, mixed smearing and laddering of DNA fragments in gills and liver samples of both fish species collected from the polluted areas indicate an intricate pollution condition. Results of the present study show the significance of integrating a set of biomarkers to identify the effects of anthropogenic pollution. High concentrations of heavy metals have a potential genotoxic effects, and genotoxicity is possibly related to agricultural and domestic activities.

Actinopolyspora egyptensis sp. nov., a new halophilic actinomycete

A halophilic actinomycete, designated HT371T, was isolated from a soil sample collected from the shore of the salty Lake Qaroun, Egypt, and was the subject of a polyphasic study. Analysis of 16S rRNA indicated that the isolate belonged to the genus Actinopolyspora and constituted a separate clade in the Actinopolyspora 16S rRNA gene tree with similarity values of 96.5 and 96.2% with Actinopolyspora halophila DSM43834T and Actinopolyspora mortivallis DSM44261T, respectively. Isolate HT371T had chemotaxonomic and morphological properties consistent with its classification in the genus Actinopolysporaand could grow on agar plates at NaCl concentrations of up to 25% (w/v). The isolate was readily differentiated from the type strains of genus Actinopolyspora using a range of phenotypic characters. On the basis of polyphasic evidence, the strain HT371T represents a novel species for which the name Actinopolyspora egyptensis sp. nov. is proposed. The type strain is HT371T (=CGMCC 4.2041T). Key words: Actinopolyspora egyptensis sp. nov., halophilic isolate, polyphasic taxonomy.

Delineation of Shallow Subsurface Structure by Azimuthal Resistivity Sounding and Joint Inversion of VES-TEM Data: Case Study near Lake Qaroun, El Fayoum, Egypt

An azimuthal resistivity survey was conducted at the transition zone between the desert area and the cultivated land near Lake Qaroun, Egypt. This area has been affected by an east-west trending fault system as indicated from the surface geology. Apparent resistivity values were plotted along azimuth on a polar diagram. Resistivity anomalies, for most of the AB/2 values with long axes strike in a direction parallel to the contact between the desert and cultivated lands, indicate the presence of electrical macro-anisotropy, mainly due to the faulting effect, at this area. Vertical electrical soundings (VES) and transient electromagnetic (TEM) measurements were conducted at eight stations along a line that crosses the boundary between the desert and cultivated land. Joint inversion of VES-TEM data was successfully used for identification of the subsurface lithostratigraphic succession and demonstrated the effect of the fault zone on the investigated subsurface medium. Apparent anisotropy coefficients at all current electrode spacings were calculated, plotted against AB/2 values and compared with the geoelectrical cross section. The effect of the fault zone was detected at AB/2 spacings equal to 100 m and extended downward and is largely related to the depth of the fault, as indicated in the constructed cross section.

IMPORTANCE OF PROTOZOA AS FOOD TO ZOOPLANKTON AND SOME FISH SPECIES IN LAKE QAROUN, EGYPT

The relationship between the protozoan organisms and zooplankton in addition to fish predation of Lake Qaroun were herby studied. An experiment was conducted in the aquatic laboratory of Shakshouk Station-Fayoum close to Lake Qaroun using cylindrical fiberglass enclosures of 1000 liters capacity that were filled with water pumped from 0.5m depth of Lake Qaroun. The numbers and net population growth and production of the dominant protozoan organisms in absence and presence of small and large- sized zooplankton as well as two native fishes namely, Mitgil cephalus and Tilapia zillii were described. The average air and water temperatures were 27.7±2.1 and 22.6±l.lsC (mean ±SD) respectively. PH values ranged from 7.39 to 8.00 (7.74±0.13, mean±SD) while ammonium ranged from 64.39^gf 1 to 1.05mgmrl during the experiment At the start, the protozoan organisms, constituted numerically 48.12% of total zooplankton organisms that dominated by three species; Tintinnopsis kofoidi, Helicostomella subulata, and Euplots vannus. In the presence of the small-sized organisms (SS), the total protozoan number was decreased. In the presence of small and large sized organisms (SLS) the protozoan number returned to the control level The impact of the fishes was more pronounce in presence of M. cephalus than T. zilli compared to the control enclosure. Protozoan organisms were observed in the gut contents of M cephalus and T. zilli, representing 1429% and 4.69% respectively. The net population growth (NPG) was higher in control. (2.15 day') followed by SLS (2.10 day1). NPGR of T. kofoidi was the highest especially in presence of the SLS

Evaporation model of Lake Qaroun as influenced by lake salinity1

AbstractA model for estimating monthly and annual evaporation of Lake Qaroun was developed using the energy budget concept. The evaporation is estimated from the amount of solar radiation, atmospheric long‐wave radiation, back radiation and evaporative energy. A modification is made to the energy equation to allow the calculation of evaporation from saline lakes by analyzing data from four evaporation pans with different salinities.The model simulations were checked against evaporation rates measured by Mankarous WF (1979. Hydrology of Lake Qaroun. MSc thesis, Faculty of Engineering, Cairo University, Cairo, Egypt). The monthly comparison shows that the model gives an acceptable accuracy with a relative error ranging from −12.4 to +12.9%. The model produces reliable results in terms of annual prediction with a maximum percent error of 3% and the minimum of −2.7%. The standard deviation of differences indicates that there is a good probability of obtaining simulated values within 0.8 mm (in May) to within 22.2 mm (in December) of measured values. Copyright © 2001 John Wiley & Sons, Ltd.

DISTRIBUTION AND SALINITY RANGES OF ZOOPLANKTON ORGANISMS AT EL-FAYOUM DEPRESSION (EL-FAYOUM-EGYPT)

Distribution and salinity ranges of the different zooplankton species at Ei Fayoum depression (El Wadi drain, Wadi El-Rayan Lakes, Fish Farms, Lake Qaroun, and EMISAL company ponds were discussed 18 species of Protozoa, 39 of Rotifera, 10 of Cladocera, 9 of Copepoda and only one Branchiopod were found, Moreover, the Tardigrad Macrobiotus macronyx and the Qstracod Cyprideis torosa in addition to the larvae of some benthic invertebrates were also obtained. Water of the studied area had a salinity range from 1.7 to 322 %o. In distribution, the species numbers were mostly decreased with increasing salinity. Some species werefoundtobeeujyhalineas5racA/o«usj7//caft'to (1.7-127.7 %o), Hexarthra oxyuris (2.5-73J%o),Keratellatropicaand!C valga { 1.7-42 %o for the two species ), while all the Cladocera were stenohaline. On the other hand, thirteen species were endemic to its area.

Strategies for agricultural development in the Fayoum area, Egypt

With the present regime of irrigation supplies to the Fayoum province of Egypt, there is no real problem regarding the increase in water levels of Lake Qaroun which is the major recipient of drainage water. Future developments should therefore concentrate on solving the problem of peak supplies for agricultural use. It has been proposed to remedy the shortage caused by further agricultural developments by increasing the system capacity by 20%. There is, however, an alternative approach which requires no engineering work; this is to change the cropping pattern by introducing rotations which reduce peak water requirements. A simplified water balance based on available data is prepared in order to acquire a better understanding of the whole situation and to set up a strategy for future agricultural development. The developed strategy takes into account the limitations imposed by the closed system of the Fayoum basin such as the irrigation efficiency, the Lake Qaroun optimum water level, land reclamation possibilities, Wadi Rayan drainage surplus, and salt concentrations in Lake Qaroun.

Silicified reed plants from the Fayum, Egypt

Silicified reed remains of Bambusa sp. have been found in Pleistocene lacustrine diatomaceous deposits near Qaroun lake. Silicification was primarily a paradiagenetic (halmyrolytic) process involving degradation in an anaerobic environment and polymerization. The silica is considered to have been supplied by interstitial solutions rather than diatom skeletons.

Successful Stocking of Lake Qaroun with Mullets (Mugil cephalis Linn. and M. capito Cuv.) from the Mediterranean

Internationale Revue der gesamten Hydrobiologie und HydrographieVolume 33, Issue 4 p. 434-439 Article Successful Stocking of Lake Qaroun with Mullets (Mugil cephalis Linn. and M. capito Cuv.) from the Mediterranean Hussein Faouzi, Hussein Faouzi EgyptSearch for more papers by this author Hussein Faouzi, Hussein Faouzi EgyptSearch for more papers by this author First published: 1936 https://doi.org/10.1002/iroh.19360330403Citations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume33, Issue41936Pages 434-439 RelatedInformation