30 resultados para Nasir-Mohammed, Sultan of Egypt, 1284-1341.

em Aquatic Commons


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The configuration for the eastern side of the Gulf of Suez was studied over 241 km from Ras Mohammed to Ras Sudr including 35 station. Litters, tar balls and aged oil patches aggregated in considerable amounts on the beach and shore line of the middle part due to the oil spills from off-shore oil wells. A large reef flat in the shallow intertidal waters exists at stations 1 and 2 (Ras Mohammed, Protected area) and spars coral patches are less frequent at the Stations from 7 to 13. Density and diversity of marine benthos were higher on hard and cobble bottoms compared to muddy sand and sandy substrates. The assemblages of the benthic fauna are dominated by the gastropod Courmya (Thericium) vulgata; the bivalve Brachiodontes variabilis, and the barnacles Chthamalus stellatus, Balanus amphitrite and Tetraclita rubescens. The distribution of the algal cover in the intertidal region shows high abundance of the brown algae, Sargassum latifolium; padina pavonica and Cystoseira trinodis rather than the green and red algae. These species are found in both polluted and unpolluted areas. The changes in benthic structures in the study area depend not only on the state of pollution but also on the type of substrates.

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This paper presents the length-weight relationship parameters (a and b) for 29 fish species, belonging to 16 families, taken by otter trawl fishing from Egyptian Mediterranean waters. The b values obtained ranged from 2.50 to 3.44 (with a mean of 2.926).

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The Egyptian aquaculture industry provides more than 100,000 full-time or part-time jobs and produces the country’s least-expensive farmed animal protein. Thus, aquaculture plays an important role in both sustaining livelihoods and improving the diet quality and nutritional health of Egyptians, including a significant proportion of the 25.5% who are resource-poor. Recognizing this dual role, WorldFish has promoted sustainable growth in Egyptian aquaculture for more than 20 years. Through its work, WorldFish has identified a lack of quality data about fish consumption preferences and practices. Eager to fill this knowledge gap, WorldFish partnered with the Environment and Development Group (EDG) to study consumption of fish, red meat and poultry among the resource-poor in Egypt. This study aimed to characterize current consumer preferences for and consumption patterns of animal-source foods, comparing red meat, poultry and fish. The resulting data is meant to contribute to a better understanding of what drives demand for fish among the resource-poor in Egypt, allowing value chain actors to more successfully market their products to this segment of the population.

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This study deals with seasonal variations, natural correlations and similarities of fouling assemblages on exposure panels in the Suez Bay during January 1992 to January 1993. Three main sources of pollutions flow into the bay; industrial waste products, domestic drainage of Suez city and ships' oil and refuse.The fouling assemblages on the test pan els after various periods (1, 2 and 3 months) belonged mainly to the algae (Ulva rigida), polychaetes (Hydroides elegans), Cirripedes (Balanus amphitrite) and amphipods. The fouling at the lst station was relatively more dense than at the 2nd station during the summer and autumn seasons. The lowest productivity was achieved at the 3rd station which was considered less polluted being offshore water. The overall paucity of fouling in the bay is because of the silt covering the submerged surfaces, particularly at the 2nd station, leading to the prevention of the settlements or establishment of fouling organisms. The seasonal changes in the intensity of fouling assemblages on submerged surfaces in seawater seems to be closely related to seasonal variations in water temperature. The great fouling communities on the buoys and long exposure panels showed a remarkable variety of species and density rather than on short term exposures, which were more dense during warmer months.

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This work focuses on four marine sites in the Mediterranean Sea around the Nile Delta, Egypt. Surface water samples were collected seasonally during 2003. The concentrations of some heavy metals in dissolved form (Fe, Mn, Zn, Cu, Ni and Pb) are evaluated. The levels of heavy metals in the coastal waters were 11.92-30.4512µglˉ¹ for Fe; 5.79-17.36 µglˉ¹ for Zn; 0.30-0.83µglˉ¹ for Cu; 0.51-2.90µglˉ¹ for Ni and 0.53-10.31µglˉ¹ for Pb. These are compared, with sites in the estuaries and outlets of the Nile Delta. Fe (19.72-60.33µglˉ¹); Mn (12.63-35.60µglˉ¹); Zn (2.67-22.00); Cu (0.56-1.67µglˉ¹); Ni (1.43-3.73µglˉ¹); Pb (1.72-59.7µglˉ¹). The results showed a remarkable decrease in the concentrations of different heavy metals with increased salinity. Comparing the present data with the minimal risk concentration reported by WQC, the distribution of heavy metals was significantly lower in coastal sea water of the Mediterranean Sea off Egypt. The study indicated also that the average contents of Ni and Pb are slightly high in the area of water exchange than those reported by WQC.

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Increases in coastal development and human activities leading to sedimentation degrade the quality of water; disturb the natural structure and functions of aquatic communities. The Suez Gulf is a large semi-closed area (~625 km long coastline).The assemblages of bottom fauna were studied qualitatively and quantitatively in the shallow intertidal waters along the western coast of the Suez Gulf. The quality of seawater and sediment structures were analyzed. The distribution of macro-benthos included a total of 38 species of Gastropoda and 9 Bivalvia; and 25 species from the other invertebrates included 7 groups namely, Rhizostoma, Polychaeta, Cirripedia, Amphipoda, Isopoda, Decapoda and Echinodermata. The most dominant group among invertebrate groups was the Polychaeta which included 4 species: Hydroides elegans, Perinereis cultilifera, Perinereis nuntia and Ophelina acuminata. The Cirripedia were represented by 3 species namely, Balanus amphitrite, Chithamalus challengeri and Tetraclita squamosa. The variations in the numerical abundance and biomass of bottom fauna studied between the observation periods and at sampling sites. There was a marked increase in benthos biomass at St. IV (Ras Gharib) yielding an average of 318.8 g/m² in which the gastropod community represented the dominant species in collected samples reaching 270.28 g/m² (84.4% of the total biomass) and numerically numbered 116 ind./m². Veliger larvae of bivalves and gastropods appeared to be present in the plankton for long periods and their production seems to be continuous throughout the year. In the intertidal zone of the Suez Gulf, the values of pH varied within narrow limits. Water temperature and salinity seemed to be important in the distribution and abundance of the macro-benthos communities in the study areas. The organic content in shallow intertidal waters and sediments indicated high values in the central part of the Gulf of Suez.

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Total concentrations and chemical forms of heavy metals in sediment samples from the Gulf of Suez and the northern part of the Red Sea, collected during January 2003, were determined by atomic absorption spectrometry. Maximum concentrations of 49.56, 65.42, 33.52 and 3.52 µg/g were recorded for total Cu, Zn, Pb and Cd respectively at Adabiya location. These may reflect the high contribution of land-based activities in the northern part of the Gulf. Also, high percentages of heavy metals were found in the residual fraction (Cu=78.61, Zn=77.10 and Pb=66.80%) while a high percentage of Cd was found in the carbonate fraction (45.82%). However, few or negligible percentages were recorded in the exchangeable fractions (Cu=0.51, Zn=1.57 and Pb=1.74%). Concentration of Cd in the exchangeable fraction was too low to be detected.

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Trace elements associated with organic subfractions (humic, fulvic, and non-humic substances) were identified for seven core sediments from Lake Mariut, Egypt. Results indicated that the amounts of trace metals in humic acid and non-humic substances decreased in the following order: Zn>Cu>Pb>Cr>Cd, while in fulvic acid the order the order was Cu>Zn>Pb>Cr>Cd. There is a higher contribution of Zn, Pb, Cu and Cr in humic acid compared to fulvic acid in most samples. Slight changes in the amounts of cadmium bounded with humic and fulvic acids was also found.

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Based on the freshwater and seawater budgets, the mean in/out water fluxes as well as the monthly changes in freshwater content were determined in Lake Manzalah. About 6693 x 10^6m^3 of fresh and brackish water inflow to the lake annually through the main drains discharging into the southeastern basin. Allowances of precipitation (105.7 x 10^6m^3/y) and evaporation (1075 x 10^6m^3/y) yield a net runoff of 5723 x 10^6m^3/y. The average changes in the freshwater content (dF) of the lake was 547.0 x 10^6m^3 with the maximum i.e. 72.4 x 10^6m^3 in July. Using the quantity of inflowing and outflowing water through Boughaz El-Gamil (Lake-Sea connection), the change in water volume relative to sea level change was 549 x 10^6m^3/y. The sea-level height (dh) induced an average monthly change of 6.5 cm. Using the amount of freshwater discharge as well as the lake volume, the lake water is replaced every 48 days.

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This study includes determination and discussion of the texture and heavy mineral compositions of some modem Nile Delta coastal sands (river, coastal dune, beach-face, and nearshore marine) in order to delineate the process and factors that regulate the size distribution of heavy mineral grains comprising these coastal sands. Textural analysis of unseparated bulk samples indicate that the examined four types of sands differ in their mean grain sizes and degree of sorting. However, analysis of size distribution curves of 10 heavy mineral species or group of species in the four environments having the same general shape and nearly similar in that general order of arrangement. However, these curves vary both in median sizes and sorting. The size distribution of a heavy mineral in the Nile Delta coastal sands appear to depend on: (1) range of grain size fractions in each sample, (2) relative availability of heavy mineral in each size grade of the sample, (3) specific gravity of minerals comprising these sands, and (4) some other unknown factor or factors. Results of size measurement of heavy minerals indicated that increasing specific gravity is accompanied by increasing fineness of the heavy minerals. This study may be useful in search for marine placers and understanding the processes of grain-sorting on the sea beaches.

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Surface- and bottom-water samples were collected from October 1996 to August 1997 to study levels of iron, copper, and cadmium species in their dissolved labile as well as non-labile and particulate forms in the waters of El-Mex Bay. The results showed that the non-labile concentration of the metals was generally more abundant than that of the labile form: its content reached more than 90% of the total dissolved metal for Cu and more than 80% for Fe. The particulate form was almost at the level of the labile form. The annual concentration of the trace metals of the labile form was 13 µglˉ¹ for Fe; 3µglˉ¹ for Cu, and 1.2 µglˉ¹ for Cd in the surface- and bottom-waters.

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bulletin which documented the major and important springs in the state (Ferguson et al., 1947). This publication was revised in 1977, with many previously undocumented springs and many new water-quality analyses being added (Rosenau et al., 1977). The Florida Geological Survey's report on first magnitude springs (Scott et al., 2002) was the initial step in once again updating and revising the Springs of Florida bulletin. The new bulletin includes the spring descriptions and water-quality analyses from Scott et al. (2002). Nearly 300 springs were described in 1977. As of 2004, more than 700 springs have been recognized in the state and more are reported each year. To date, 33 first magnitude springs (with a flow greater than 100 cubic feet per second or approximately 64.6 million gallons of water per day) have been recognized in Florida, more than any other state or country (Rosenau et al., 1977). Our springs are a unique and invaluable natural resource. A comprehensive understanding of the spring systems will provide the basis for their protection and wise use. (Document pdf contains 677 pages)

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The purpose of the workshop was to enable professionals and organizations working with fishing communities in response to HIV and AIDS in Africa to share experiences, appraise the efficacy of their approaches and identify actions in research and development that will further improve their impact. The workshop pursued and achieved the following objectives: 1)Review and compare research findings and approaches applied in response to HIV and AIDS in fishing communities and the wider fishery sector. 2)Identify good practice examples for wider application. 3)Identify next steps in development and research to scale up these examples. 4)Initiate a network of practitioners in Africa for capacity building, scaling-up and further development of approaches. The range of papers presented at the conference reveals the diversity of responses to HIV and AIDS in the fishery sector at all levels. The papers discussed a range of issues within this broad remit, from community level impacts of disease to policy implementation, from spatial mapping to theatre as a mode of communication. (Document contains 92 pages)

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The culture of tilapia has a long history in Africa. Fossil remains of members of the genus have been found which are about 18 million years old (Fryer and Iles, 1972). Oreochromis niloticus was the subject of detailed observations in Egypt of 5,000 years ago. A bas relief of 2,500B.C. depicts tilapia being reared in ponds in Egypt. However, despite this long history the prolific nature of this fish results in very high populations in pond culture systems. Consequently small size fish are harvested. Several methods have thus been tried to control the excessive reproduction of tilapia in captivity with only partial success. This paper reports how large size tilapia especially O. niloticus averaging at least 150g per piece can be commercially produced using floating net cages in the marine environment