The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square met...The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square metre belt transects along each permanent line transect at 20 metre intervals were used to collect data. The data were subjected to univariate and multivariate analyses. Spatial variations of epibenthic echinoderm abundance were assessed with one-way analysis of variance. Hierarchical agglomerative clustering was used to identify and illustrate the similarities in echinoderm abundance between line transects and between belt transects. Indices of richness (d), diversity (H'), evenness (J') and dominance (C) were used to explain the diversity of epibenthic echinoderm species. The distribution pattern of each echinoderm species was determined in each permanent line transect. A total of 986 individuals were recorded within sixteen species of epibenthic echinoderms in the four line transects. Holothuriidae was the dominant family (5 species and 342 individuals). The most abundant echinoderms species was Pearsonothuria graeffei (77 individuals, about 7.81%). Abundances intra-transects and intra-families were insignificant (f = 1.67, p = 0.183, df = 3 and f = 3.24, p = 0.083, df = 9, respectively). The highest values of Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Margalef species richness index (d), and Simpson Dominance index (C) were 2.738, 0.9875, 2.791 and 0.07159, respectively. The distribution patterns of all species in the study transects varied between clumped and uniform, with the exception of Asthenosoma varium of the Echinothuridae family, which had clumped distribution patterns in all transects. The study concluded that Dungonab Bay supports rich and diverse communities of epibenthic echinoderms.展开更多
Data obtained on hydrography and currents in meridional sections in the Gulf of Aqaba and the Red Sea in November 2013 and March 2015 were used to determine the extent of contribution of Gulf of Aqaba Water(GAW)to the...Data obtained on hydrography and currents in meridional sections in the Gulf of Aqaba and the Red Sea in November 2013 and March 2015 were used to determine the extent of contribution of Gulf of Aqaba Water(GAW)to the formation of Red Sea waters.The southward flow across the Strait of Tiran was^0.02 Sv in both periods which is direct evidence of significant contribution of GAW to Red Sea waters in autumn-winter.A multiple tracer analysis using temperature,salinity,and dissolved oxygen showed that the GAW,on entry into Red Sea,bifurcates into two branches.The upper branch exiting the Strait in the depth range 150-220 m has densities between 28.3 and 28.5,continues to flow at the same depths,and feeds the Red Sea Overflow Water(RSOW).The lower branch that exits between 220 and 250 m above the sill cascades down its southern face,mixes with northward recirculating branch of Red Sea Deep Water(RSDW)and sinks to the bottom and forms part of southward-flowing RSDW.Contribution of GAW to northern Red Sea waters below 100 m depth was 36±0.4%in November 2013 and 42.1±5.4%in March 2015.GAW is traceable down to 17-19°N in RSDW and RSOW.Volume contribution of GAW to RSOW was 9.6*1012 m3,about 50%higher than that for RSDW(6*1012 m3).Analyses of the data from R.V.Maurice Ewing cruise in 2001 gave similar results and lend support for these deductions.展开更多
Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this...Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.展开更多
The coastline changes along Yemen's the Red Sea (Al-muka, Al-khohah, Al-tiaf, Ras Katib and Al- Urji spits) were studied using a series of landsat images (MSS, TM and ETM + , 1972, 1989, 2000, 2006), coupled wit...The coastline changes along Yemen's the Red Sea (Al-muka, Al-khohah, Al-tiaf, Ras Katib and Al- Urji spits) were studied using a series of landsat images (MSS, TM and ETM + , 1972, 1989, 2000, 2006), coupled with geomorphological, sedimentological and meteorological findings. Comparison of satellite images provided a viable means for establishing long-term coastal changes (accretion and erosion) as observed in the studied spits (Al-Urj, Ras Sham, Ras Maemoon, Ras Katib, Al-Mandar, Nukhaylah, Mujamilah, Ras Ashab Abu-Zahr and Mukha). The rate of the spit accretion has the greatest value up to 89 pixel/year corresponding to 72 290 m2/year in Mukha, while the spit erosion shows greatest value up to 131 pixel/year corresponding to 106 404 m2/year in Mujamilab. The patterns of accretion and erosion along the spits depend on the spit direction, natural processes mainly of wave-induced longshore currents, the sediments supply and depth of sea.展开更多
To assess the quality of the Egyptian Red Sea coastal waters for the sustainable use and development, due to its importance for the national income, four field campaigns were annually carried out during the period fro...To assess the quality of the Egyptian Red Sea coastal waters for the sustainable use and development, due to its importance for the national income, four field campaigns were annually carried out during the period from 2011-2013 to investigate the hydrography, nutrient salts, heavy metals and petroleum hydrocarbons. Except for the area of Bir Shalatein, the results of beach litter cleared out that the shoreline of the studied area is not affected by man-made litter. No sewage could be observed. The results of the present study showed that water temperature followed seasonal changes in air temperature. Red Sea water is more saline than adjacent Arabian Sea. DO revealed high values and presence of well oxygenated waters. Minor changes in the distribution of pH, BOD, DOM and COD, revealed that limited effects of human impacts and depend mainly on the dynamics of its water as well as on the geographical location. Low Chl-a and TSM concentrations and high transparency revealed that also the effect of human impacts is almost negligible. Significantly higher sea water temperatures, TSM, pH, DO, BOD, DOM, and COD were observed in summer season compared to their corresponding values in winter season. Dissolved inorganic nitrogen concentrations were quite low because there is little nutrient input from soil, agriculture and pollution on land. Based on the annual mean values, the pattern concentrations of dissolved inorganic nitrogen forms followed the order: NO<sub>3</sub> > NH<sub>4</sub> > NO<sub>2</sub>. The Red Sea coastal waters are classified as oligotrophic to mesotrophic state. A remarkable increase of PO<sub>4</sub> concentration was observed in the middle Red Sea stations due to huge amounts of effluents enriched with phosphate from the main shipping and industry of Phosphate Companies. SiO<sub>4</sub> displayed a large variability due to the supply of SiO<sub>4</sub>, which flows in the Red Sea through the strait of Bab El-Mandab, biological consumption, organic matter decomposition and the partial dissolution of quartz particle transported to the sea from the surrounding desert during sand storms. Concentrations of ammonia, phosphorus, total nitrogen, and total phosphorus were significantly higher in summer compared to their corresponding values in winter. In general, the majority of TN and TP in winter were in the form of organic-N (91.3%) and organic P (96.8%). The mean DIN/DIP ratio revealed high nitrogen concentrations in comparison with that of phosphorous and the surface coastal waters of the Red Sea are principally, P-limited for phytoplankton growth with higher values in winter season compared to summer season. Concentrations of heavy metals were quite low most probably due the absence of major local impacts of any land-based sources and/or any major negative impacts of coastal tourism. Regional variations were almost negligible and except for Mn, Cd, and Hg insignificant seasonal variations were observed. The present study revealed concentrations for metals in the acceptable levels. Furthermore, concentrations of petroleum hydrocarbons were significantly higher in winter than in summer which is mainly attributed to the increase in the rate of evaporation for petroleum hydrocarbons in summer. In general, the maximum concentration was much lower than the harmful concentrations reported for seawater. Correlation coefficients as well as principle component analysis (PCA) were applied.展开更多
The negative effects of natural disasters on human life exist from the foot and did not occur at a specific time but found since the creation of mankind. Humans coexist with extreme events all the time, only when the ...The negative effects of natural disasters on human life exist from the foot and did not occur at a specific time but found since the creation of mankind. Humans coexist with extreme events all the time, only when the intensity of the event becomes greater than a certain level there is a resulting disaster. Small earthquakes occur all of the time with no adverse effects. Only large earthquakes cause disasters. Statistical analysis reveals that larger events occur less frequently than small events. Through the large number of seismic events, we find that at the end of the year may have a series of seismic events with different values depending on the strength of activity whether it is high or low on Richter scale and the assessment is only for the greatest value in a year even if recurring this value and the volume of dangerous increases and the frequency of their occurrence according to an ongoing activity, major disasters result from a small number of events and sustained results in a large and devastating event, and can be represented by these results and amounts On a log-scale which points are almost on a straight line and a clear indication of the evaluation event. Through previous data analysis we can understand the following events behavior for coordination and guidance on the development of evacuation plans on the expected future and use a Weibull equation to estimate the frequency of the event and the return again as a percentage for each event and the probability of the occurrence of a particular earthquake to some degree on the Richter scale in the sea during any period. Past records of earthquakes at the West Coast of the Kingdom of Saudi Arabia (Red Sea) for years 1913-2016 are used to predict future conditions concerning the annual frequency, the return period, the percentage probability for each event, and the probability of a certain-magnitude earthquake occurring in the region during any period.展开更多
Analysis of high-resolution 4 km sea surface temperature, Chlorophyll a (Chl a), and wind datasets provides a detailed description of the spatio-temporal seasonal succession of phytoplankton biomass in the Red Sea a...Analysis of high-resolution 4 km sea surface temperature, Chlorophyll a (Chl a), and wind datasets provides a detailed description of the spatio-temporal seasonal succession of phytoplankton biomass in the Red Sea and Gulf of Aden. Based on Moderate Resolution Imaging Spectroradiometer on-board aqua platform (MO- DIS Aqua) data andsynoptic observations in the Red Sea, Chl a varies from north to south, with the northern part appearing to be oligotrophic. This is likely due to the absence of strong mixing and low nutrient intru- sion in comparison to the southern part during winter. In the Gulf of Aden, the emergence of upwelling cell is clearly evident along the coast of Yemen, and is only distinct from the summer-autumn seasons. Most notable is the pulsating nature of the upwelling, with warm and cold events clearly distinguished with phytoplankton response to this physical forcing also evident. The phytoplankton biomass distribution varies considerably between the two regions of study. In both study areas, water temperature and prevailing winds control nutrient concentrations.展开更多
Zooplankton and zooneuston observations were made at seven stations(four from the Gulf of Aqaba and three from the northern Red Sea), during September and October 2016. The main objective of this study was to assess t...Zooplankton and zooneuston observations were made at seven stations(four from the Gulf of Aqaba and three from the northern Red Sea), during September and October 2016. The main objective of this study was to assess the variability of nycthemeral fauna in relation to the sampling methods using two different types of nets namely,WP2 net and Neuston net along the two study sites, i.e., the Gulf of Aqaba and the northern Red Sea. Zooplankton was sampled vertically using a standard WP2 net from a depth of 200 m to the surface, whereas zooneuston was made using a standard Neuston net from a depth of 0–10 cm of the water surface. Total zooplankton density was maximum during night time((617.83 ± 201.84) ind./m^3) at the Gulf of Aqaba and total zooneuston was maximum during night at the northern Red Sea((60.94±29.48) ind./m^3), respectively. The most abundant taxa were Copepoda, Gastropoda, Bivalva, Chaetognatha, Tunicata and Ostracoda. The abundance was almost 50% higher at night time at both the Gulf of Aqaba and the northern Red Sea. Overall, 30 taxa covering 10 phyla and 27 taxa covering 8 phyla were recorded in the Gulf of Aqaba and the northern Red Sea.展开更多
The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolu...The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary basin, active faulting and seismicity. Studies indicate that sedimentary sequences of the margin are deformed by faults and folds resulting from at least two phases of extension and a phase of uplift. During the two phases of extension due to regional plate stress the sequence was cut by set of extensional faults. While during the phase of uplift the sequence was deformed by folding and faulting. The present paper aims to clear the structural development of RSCM during these tectonic episodes, taken as particular tectonic event, by two-dimensional finite element modeling on plane strain condition. Elastic theology is assumed for the oceanic, continental and transitional crust along with syntectonic deposits. Stress field, shear stress and fault distribution suggests that mantle plume weakened the crust following rifting due to regional stress and developed the margin. These results are well consistent with those from present seismicity, active faulting and neotectonic studies.展开更多
The intensity of infestation of the epizoic stalked barnacle Octolasmis on the blue crab was calculated for a total of 180 individuals collected around Jeddah, the western Red Sea Saudi coast. More than 90% of the cra...The intensity of infestation of the epizoic stalked barnacle Octolasmis on the blue crab was calculated for a total of 180 individuals collected around Jeddah, the western Red Sea Saudi coast. More than 90% of the crabs were found bearing the Octolasmis at a prevalence rate of 92% and mean intensity of 18.5 ? 18.6(0–127 epibiont per host). The intensity of infestation increased with host size in the range 90–135 mm. Generally, females were more infested(69%) than the males(31%). Octolasmis angulata occurred mostly on the gills, and the lower side of the gill chambers was more infested(84%) than the upper side(16%) and the left side of gills was also more infested than the right side in both males and females. Further studies are still needed to examine the commensal relationship and its impact on the fishery market of the Red Sea blue crab populations.展开更多
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Is...In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands (44.55%±11.10% cover) fol-lowed by tabular forms in the Doga Islands (ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area (58.89%±15.11% cover) followed by the Jeddah coast (24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah (10.70%±8.21%) and A1-Wajh (9.81%±6.69%). The live coral cover (including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah (Northem region) and the second one comprised the middle and southem regions (Jeddah to Farassan Islands), and one outlier Rabigh.展开更多
Harrat Al-Birk volcanics are products of the Red Sea rift in southwest Saudi Arabia that started in the Tertiary and reached its climax at ~ 5 Ma.This volcanic field is almost monotonous and is dominated by basalts th...Harrat Al-Birk volcanics are products of the Red Sea rift in southwest Saudi Arabia that started in the Tertiary and reached its climax at ~ 5 Ma.This volcanic field is almost monotonous and is dominated by basalts that include mafic-ultramafic mantle xenoliths(gabbro,websterite,and garnet-clinopyroxenite).The present work presents the first detailed petrographic and geochemical notes about the basalts.They comprise vesicular basalt,porphyritic basalt,and flow-textured basalt,in addition to red and black scoria.Geochemically,the volcanic rock varieties of the Harrat Al-Birk are low- to medium-Ti,sodic-alkaline olivine basalts with an enriched oceanic island signature but extruded in a within-plate environment.There is evidence of formation by partial melting with a sort of crystal fractionation dominated by clinopyroxene and Fe-Ti oxides.The latter have abundant titanomagnetite and lesser ilmenite.There is a remarkable enrichment of light rare earth elements and depletion in Ba,Th and K,Ta,and Ti.The geochemical data in this work suggest Harrat Al-Birk basalts represent products of watersaturated melt that was silica undersaturated.This melt was brought to the surface through partial melting of asthenospheric upper mantle that produced enriched oceanic island basalts.Such partial melting is the result of subducted continental mantle lithosphere with considerable mantle metasomatism of subducted oceanic lithosphere that might contain hydrous phases in its peridotites.The fractional crystallization process was controlled by significant separation of clinopyroxene followed by amphiboles and Fe-Ti oxides,particularly ilmenite.Accordingly,the Harrat Al-Birk alkali basalts underwent crystal fractionation that is completely absent in the exotic mantle xenoliths(e.g.Nemeth et al.in The Pleistocene Jabal Akwa A1 Yamaniah maar/tuff ring-scoria cone complex as an analogy for future phreatomagmatic to magmatic explosive eruption scenarios in the Jizan Region,SW Saudi Arabia 2014).展开更多
Recombinant eel GH and yeast containing chinook salmon growth hormone (reGH and rcsGH) were incorporated into gelatin and sodium alginate (reGH GS and rcsGH GS) or polymer matrix (reGH HP55) to protect the hormone fro...Recombinant eel GH and yeast containing chinook salmon growth hormone (reGH and rcsGH) were incorporated into gelatin and sodium alginate (reGH GS and rcsGH GS) or polymer matrix (reGH HP55) to protect the hormone from proteolytic cleavage in the stomach. The diets containing reGH GS, rcsGH GS, reGH HP55 and free reGH or uncoated rcsGH were administered to red sea bream. Feeding of reGH GS, reGH HP55 and rcsGH GS diets resulted in significant increases in body weight and fork length over those of controls. These results strongly suggest that gelatin and sodium alginate as well as polymer matrix protected the hormone from proteolytic enzymes in the gastrointestinal tract to allow the bioactive hormone to enter the circulation and eventually stimulate fish growth.展开更多
Knowing Moho discontinuity undulation is fundamental to understanding mechanisms of lithosphereasthenosphere interaction, extensional tectonism and crustal deformation in volcanic passive margins such as the study are...Knowing Moho discontinuity undulation is fundamental to understanding mechanisms of lithosphereasthenosphere interaction, extensional tectonism and crustal deformation in volcanic passive margins such as the study area, which is located in the southwestern corner of the Arabian Peninsula bounded by the Red Sea and the Gulf of Aden. In this work, a 3D Moho depth model of the study area is constructed for the first time by inverting gravity data from the Earth Gravitational Model(EGM2008) using the ParkerOldenburg algorithm. This model indicates the shallow zone is situated at depths of 20 km to 24 km beneath coastal plains, whereas the deep zone is located below the plateau at depths of 30 km to 35 km and its deepest part coincides mainly with the Dhamar-Rada ’a Quaternary volcanic field. The results also indicate two channels of hot magmatic materials joining both the Sana’a-Amran Quaternary volcanic field and the Late Miocene Jabal An Nar volcanic area with the Dhamar-Rada’a volcanic field. This conclusion is supported by the widespread geothermal activity(of mantle origin) distributed along these channels,isotopic data, and the upper mantle low velocity zones indicated by earlier studies.展开更多
Monthly abundance of the subclass Copepoda was analyzed from the zooplankton samples collected at Obhur Creek, Jeddah, Saudi Arabia during December-2011 till December-2012. Zooplankton samples were collected through s...Monthly abundance of the subclass Copepoda was analyzed from the zooplankton samples collected at Obhur Creek, Jeddah, Saudi Arabia during December-2011 till December-2012. Zooplankton samples were collected through surface horizontal tows by a modified WP2 net(via. mouth diameter 50 cm, length 180 cm, 150 μm mesh size). Order Calanoida dominated the abundance with mean annual average of 75.29%. We observed abnormal protuberances on copepods, known as tumour-like anomalies(TLAs). Calanoida showed more frequent and prominent TLAs on its dorsal surface with highest mean percentage occurring during Jun. 2012(1.64%). The percentage prevalence of TLAs on the Copepoda was highest during Jun. 2012(1.36%) and least during Nov. 2012(0.03%). It is suggested that these TLAs might be caused due to the presence of potentially high levels of toxic substances, which weakens the exoskeleton and thereby making them more susceptible to infections or due to wounds from parasites or might be related to the occurrence of symbiotic tantulocarids or might be due to the radiation stress as a control measure. Whatever the reason, these TLAs have become a serious emerging threat to the aquatic food web. Our investigation is the first of its kind in the coastal waters of the Saudi Red Sea, which needs further investigations in order to elucidate the possible reasons for these abnormalities.展开更多
Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:V...Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Triaenodon obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and</span><i> </i></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"><i></i></span></i></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Hipposcarus harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><i><span style="font-family:;" "=""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">fish were purchased from Port Sudan fish central market during December 2014. The fatty acid profiles of the livers of these commercially important fish were determined. The polyunsaturated and saturated fatty acids ratio in the livers oil of </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">H. harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> was 1:2.2 and 1:1.38, respectively. The Palmatic (16:0), Pentadecenoic (12:0) and Arachidic acids were the highest in both species. The poly chain unsaturated fatty acids Linolenic (18:3n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3), Eicosapentaenoic (20:5n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) and Docosahexaenoic (22:6n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) were detected in the liver of both species. The highest values of above poly chain unsaturated fatty acids were detected in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">.</span></i></span></span>展开更多
Opening of the Red Sea started while the core of the lavas of the Ethiopian Large Igneous Province(LIP)was being erupted at;0 Ma(Hughes et al.,1991)and has continued to the Present.In the southern Red Sea,oceanic
The aim of the paper is to present a repertory of all archaeological data about the Ayla-Axum amphorae and its content. The study of these class of material will also highlight some aspects of the Early Medieval trade...The aim of the paper is to present a repertory of all archaeological data about the Ayla-Axum amphorae and its content. The study of these class of material will also highlight some aspects of the Early Medieval trade, a period in which sensible political changes occurred after the fall of the Western Roman Empire. The Ayla-Axum amphorae, found in several Red Sea's sites, are significant indicators of trading activities in the region, whose production, transport and diffusion are far from having been thoroughly investigated up to now. Although most scholars think it was used to transport date wine, at least judging on some tituli picti found in these containers, in recent years Parker and Dolinka have suggested that they might have carried garum or a similar fish-sauce produced at Ayla-AqabaI.展开更多
The expected water mixing process between Red/Dead Sea water during the proposed conveyance projects is the main target of this research. The project will ensue transporting Red Sea water to recover and maintain certa...The expected water mixing process between Red/Dead Sea water during the proposed conveyance projects is the main target of this research. The project will ensue transporting Red Sea water to recover and maintain certain level of the Dead Sea, mostly will reach <span><span><span style="font-family:;" "=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">-</span></span></span></span><span style="font-family:;" "="">395</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">m. It is found that, the two different water bodies with different EC values or different densities (salinities) are relatively divided by stable plane. This plane is defined as the BARZACH PLANE. In this study, the mixing process occurred between the Red Sea with the Dead Sea waters, located at 20</span><span style="font-family:;" "="">% </span><span style="font-family:;" "="">-</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">24% of the Dead Sea column depth based on the Barzach Plane level. During a laboratory experimental work, it is found that the mixed Red/Dead Sea water evaporates in a high rate until certain level where the solution attains oversaturated conditions with different dissolved solids. At this stage, a thin layer of solids suddenly formed and floated at the surface of the dense brine. The salinity of the captured water is so dense that floated salt layer cannot be dissolved. In addition, the formed floated salt layer at the surface prevents the below captured water to evaporate and at this stage, stalactites start to form until the excess dissolved solids are not oversaturated with any mineral.</span>展开更多
Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studie...Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studied. The study was designed to provide base line data and information on the current socio-economic situation, factors that determine the use of fishing gear, types of boats and fishing equipment, challenges facing fishers and the extent to which fishing gear and boats are related with the socio-economic characteristics of the fishers community in the study sites. Fieldwork was carried out during 2016. The study methods included a series of interviews based on questionnaires, field observations and focus group discussions. The results of the study showed that the most common fishing gears are handlines, cast nets and gillnets. The two types of boats used at the study sites are motorized fiberglass and houri (motorized and paddled) with a V-shaped hull. Boat ownership varies among fishers. Each fisher can have several types of gears in different numbers. Target fish species, season, efficiency of gear and fishing location were the main factors determining the use of fishing gear at study sites, respectively. All fishers are men and most have families of at least four people. The majority of fishers are between 21 and 50 years old and work mainly in fishing. They inherited fishing knowledge within the family, and most of them have been working in artisanal fishing for more than 10 years. Fishers have relatively good net incomes compared to other government employers in the study sites. Most fishers work full time in fishing. A small number of fishers work part-time with the possibility of undertaking other income-generating activities such as animal husbandry and seasonal agriculture. The main challenges identified by fishers at the study sites were fish prices, sea surface roughness and high cost of fishing materials, respectively. Most fishers perceived a recent decline in both catch size and abundance.展开更多
文摘The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square metre belt transects along each permanent line transect at 20 metre intervals were used to collect data. The data were subjected to univariate and multivariate analyses. Spatial variations of epibenthic echinoderm abundance were assessed with one-way analysis of variance. Hierarchical agglomerative clustering was used to identify and illustrate the similarities in echinoderm abundance between line transects and between belt transects. Indices of richness (d), diversity (H'), evenness (J') and dominance (C) were used to explain the diversity of epibenthic echinoderm species. The distribution pattern of each echinoderm species was determined in each permanent line transect. A total of 986 individuals were recorded within sixteen species of epibenthic echinoderms in the four line transects. Holothuriidae was the dominant family (5 species and 342 individuals). The most abundant echinoderms species was Pearsonothuria graeffei (77 individuals, about 7.81%). Abundances intra-transects and intra-families were insignificant (f = 1.67, p = 0.183, df = 3 and f = 3.24, p = 0.083, df = 9, respectively). The highest values of Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Margalef species richness index (d), and Simpson Dominance index (C) were 2.738, 0.9875, 2.791 and 0.07159, respectively. The distribution patterns of all species in the study transects varied between clumped and uniform, with the exception of Asthenosoma varium of the Echinothuridae family, which had clumped distribution patterns in all transects. The study concluded that Dungonab Bay supports rich and diverse communities of epibenthic echinoderms.
文摘Data obtained on hydrography and currents in meridional sections in the Gulf of Aqaba and the Red Sea in November 2013 and March 2015 were used to determine the extent of contribution of Gulf of Aqaba Water(GAW)to the formation of Red Sea waters.The southward flow across the Strait of Tiran was^0.02 Sv in both periods which is direct evidence of significant contribution of GAW to Red Sea waters in autumn-winter.A multiple tracer analysis using temperature,salinity,and dissolved oxygen showed that the GAW,on entry into Red Sea,bifurcates into two branches.The upper branch exiting the Strait in the depth range 150-220 m has densities between 28.3 and 28.5,continues to flow at the same depths,and feeds the Red Sea Overflow Water(RSOW).The lower branch that exits between 220 and 250 m above the sill cascades down its southern face,mixes with northward recirculating branch of Red Sea Deep Water(RSDW)and sinks to the bottom and forms part of southward-flowing RSDW.Contribution of GAW to northern Red Sea waters below 100 m depth was 36±0.4%in November 2013 and 42.1±5.4%in March 2015.GAW is traceable down to 17-19°N in RSDW and RSOW.Volume contribution of GAW to RSOW was 9.6*1012 m3,about 50%higher than that for RSDW(6*1012 m3).Analyses of the data from R.V.Maurice Ewing cruise in 2001 gave similar results and lend support for these deductions.
基金supported by the National Key Technology Research and Development Program of China (Grant No.2006BAD30B01)the Research Award Fund for Excellent Young Scientist of Shandong Province,China (Grant No.BS2009HZ005)
文摘Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.
文摘The coastline changes along Yemen's the Red Sea (Al-muka, Al-khohah, Al-tiaf, Ras Katib and Al- Urji spits) were studied using a series of landsat images (MSS, TM and ETM + , 1972, 1989, 2000, 2006), coupled with geomorphological, sedimentological and meteorological findings. Comparison of satellite images provided a viable means for establishing long-term coastal changes (accretion and erosion) as observed in the studied spits (Al-Urj, Ras Sham, Ras Maemoon, Ras Katib, Al-Mandar, Nukhaylah, Mujamilah, Ras Ashab Abu-Zahr and Mukha). The rate of the spit accretion has the greatest value up to 89 pixel/year corresponding to 72 290 m2/year in Mukha, while the spit erosion shows greatest value up to 131 pixel/year corresponding to 106 404 m2/year in Mujamilab. The patterns of accretion and erosion along the spits depend on the spit direction, natural processes mainly of wave-induced longshore currents, the sediments supply and depth of sea.
文摘To assess the quality of the Egyptian Red Sea coastal waters for the sustainable use and development, due to its importance for the national income, four field campaigns were annually carried out during the period from 2011-2013 to investigate the hydrography, nutrient salts, heavy metals and petroleum hydrocarbons. Except for the area of Bir Shalatein, the results of beach litter cleared out that the shoreline of the studied area is not affected by man-made litter. No sewage could be observed. The results of the present study showed that water temperature followed seasonal changes in air temperature. Red Sea water is more saline than adjacent Arabian Sea. DO revealed high values and presence of well oxygenated waters. Minor changes in the distribution of pH, BOD, DOM and COD, revealed that limited effects of human impacts and depend mainly on the dynamics of its water as well as on the geographical location. Low Chl-a and TSM concentrations and high transparency revealed that also the effect of human impacts is almost negligible. Significantly higher sea water temperatures, TSM, pH, DO, BOD, DOM, and COD were observed in summer season compared to their corresponding values in winter season. Dissolved inorganic nitrogen concentrations were quite low because there is little nutrient input from soil, agriculture and pollution on land. Based on the annual mean values, the pattern concentrations of dissolved inorganic nitrogen forms followed the order: NO<sub>3</sub> > NH<sub>4</sub> > NO<sub>2</sub>. The Red Sea coastal waters are classified as oligotrophic to mesotrophic state. A remarkable increase of PO<sub>4</sub> concentration was observed in the middle Red Sea stations due to huge amounts of effluents enriched with phosphate from the main shipping and industry of Phosphate Companies. SiO<sub>4</sub> displayed a large variability due to the supply of SiO<sub>4</sub>, which flows in the Red Sea through the strait of Bab El-Mandab, biological consumption, organic matter decomposition and the partial dissolution of quartz particle transported to the sea from the surrounding desert during sand storms. Concentrations of ammonia, phosphorus, total nitrogen, and total phosphorus were significantly higher in summer compared to their corresponding values in winter. In general, the majority of TN and TP in winter were in the form of organic-N (91.3%) and organic P (96.8%). The mean DIN/DIP ratio revealed high nitrogen concentrations in comparison with that of phosphorous and the surface coastal waters of the Red Sea are principally, P-limited for phytoplankton growth with higher values in winter season compared to summer season. Concentrations of heavy metals were quite low most probably due the absence of major local impacts of any land-based sources and/or any major negative impacts of coastal tourism. Regional variations were almost negligible and except for Mn, Cd, and Hg insignificant seasonal variations were observed. The present study revealed concentrations for metals in the acceptable levels. Furthermore, concentrations of petroleum hydrocarbons were significantly higher in winter than in summer which is mainly attributed to the increase in the rate of evaporation for petroleum hydrocarbons in summer. In general, the maximum concentration was much lower than the harmful concentrations reported for seawater. Correlation coefficients as well as principle component analysis (PCA) were applied.
文摘The negative effects of natural disasters on human life exist from the foot and did not occur at a specific time but found since the creation of mankind. Humans coexist with extreme events all the time, only when the intensity of the event becomes greater than a certain level there is a resulting disaster. Small earthquakes occur all of the time with no adverse effects. Only large earthquakes cause disasters. Statistical analysis reveals that larger events occur less frequently than small events. Through the large number of seismic events, we find that at the end of the year may have a series of seismic events with different values depending on the strength of activity whether it is high or low on Richter scale and the assessment is only for the greatest value in a year even if recurring this value and the volume of dangerous increases and the frequency of their occurrence according to an ongoing activity, major disasters result from a small number of events and sustained results in a large and devastating event, and can be represented by these results and amounts On a log-scale which points are almost on a straight line and a clear indication of the evaluation event. Through previous data analysis we can understand the following events behavior for coordination and guidance on the development of evacuation plans on the expected future and use a Weibull equation to estimate the frequency of the event and the return again as a percentage for each event and the probability of the occurrence of a particular earthquake to some degree on the Richter scale in the sea during any period. Past records of earthquakes at the West Coast of the Kingdom of Saudi Arabia (Red Sea) for years 1913-2016 are used to predict future conditions concerning the annual frequency, the return period, the percentage probability for each event, and the probability of a certain-magnitude earthquake occurring in the region during any period.
文摘Analysis of high-resolution 4 km sea surface temperature, Chlorophyll a (Chl a), and wind datasets provides a detailed description of the spatio-temporal seasonal succession of phytoplankton biomass in the Red Sea and Gulf of Aden. Based on Moderate Resolution Imaging Spectroradiometer on-board aqua platform (MO- DIS Aqua) data andsynoptic observations in the Red Sea, Chl a varies from north to south, with the northern part appearing to be oligotrophic. This is likely due to the absence of strong mixing and low nutrient intru- sion in comparison to the southern part during winter. In the Gulf of Aden, the emergence of upwelling cell is clearly evident along the coast of Yemen, and is only distinct from the summer-autumn seasons. Most notable is the pulsating nature of the upwelling, with warm and cold events clearly distinguished with phytoplankton response to this physical forcing also evident. The phytoplankton biomass distribution varies considerably between the two regions of study. In both study areas, water temperature and prevailing winds control nutrient concentrations.
基金The Deanship of Scientific Research(DSR),at King Abdulaziz University,Jeddah,Saudi Arabia,under contract No.I-002-37
文摘Zooplankton and zooneuston observations were made at seven stations(four from the Gulf of Aqaba and three from the northern Red Sea), during September and October 2016. The main objective of this study was to assess the variability of nycthemeral fauna in relation to the sampling methods using two different types of nets namely,WP2 net and Neuston net along the two study sites, i.e., the Gulf of Aqaba and the northern Red Sea. Zooplankton was sampled vertically using a standard WP2 net from a depth of 200 m to the surface, whereas zooneuston was made using a standard Neuston net from a depth of 0–10 cm of the water surface. Total zooplankton density was maximum during night time((617.83 ± 201.84) ind./m^3) at the Gulf of Aqaba and total zooneuston was maximum during night at the northern Red Sea((60.94±29.48) ind./m^3), respectively. The most abundant taxa were Copepoda, Gastropoda, Bivalva, Chaetognatha, Tunicata and Ostracoda. The abundance was almost 50% higher at night time at both the Gulf of Aqaba and the northern Red Sea. Overall, 30 taxa covering 10 phyla and 27 taxa covering 8 phyla were recorded in the Gulf of Aqaba and the northern Red Sea.
基金the Japanese Government Ministry of Education and Sports for the Monbukagakusho scholarship
文摘The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary basin, active faulting and seismicity. Studies indicate that sedimentary sequences of the margin are deformed by faults and folds resulting from at least two phases of extension and a phase of uplift. During the two phases of extension due to regional plate stress the sequence was cut by set of extensional faults. While during the phase of uplift the sequence was deformed by folding and faulting. The present paper aims to clear the structural development of RSCM during these tectonic episodes, taken as particular tectonic event, by two-dimensional finite element modeling on plane strain condition. Elastic theology is assumed for the oceanic, continental and transitional crust along with syntectonic deposits. Stress field, shear stress and fault distribution suggests that mantle plume weakened the crust following rifting due to regional stress and developed the margin. These results are well consistent with those from present seismicity, active faulting and neotectonic studies.
文摘The intensity of infestation of the epizoic stalked barnacle Octolasmis on the blue crab was calculated for a total of 180 individuals collected around Jeddah, the western Red Sea Saudi coast. More than 90% of the crabs were found bearing the Octolasmis at a prevalence rate of 92% and mean intensity of 18.5 ? 18.6(0–127 epibiont per host). The intensity of infestation increased with host size in the range 90–135 mm. Generally, females were more infested(69%) than the males(31%). Octolasmis angulata occurred mostly on the gills, and the lower side of the gill chambers was more infested(84%) than the upper side(16%) and the left side of gills was also more infested than the right side in both males and females. Further studies are still needed to examine the commensal relationship and its impact on the fishery market of the Red Sea blue crab populations.
文摘In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands (44.55%±11.10% cover) fol-lowed by tabular forms in the Doga Islands (ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area (58.89%±15.11% cover) followed by the Jeddah coast (24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah (10.70%±8.21%) and A1-Wajh (9.81%±6.69%). The live coral cover (including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah (Northem region) and the second one comprised the middle and southem regions (Jeddah to Farassan Islands), and one outlier Rabigh.
基金funded by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,under Grant No.(D1435-710-145)
文摘Harrat Al-Birk volcanics are products of the Red Sea rift in southwest Saudi Arabia that started in the Tertiary and reached its climax at ~ 5 Ma.This volcanic field is almost monotonous and is dominated by basalts that include mafic-ultramafic mantle xenoliths(gabbro,websterite,and garnet-clinopyroxenite).The present work presents the first detailed petrographic and geochemical notes about the basalts.They comprise vesicular basalt,porphyritic basalt,and flow-textured basalt,in addition to red and black scoria.Geochemically,the volcanic rock varieties of the Harrat Al-Birk are low- to medium-Ti,sodic-alkaline olivine basalts with an enriched oceanic island signature but extruded in a within-plate environment.There is evidence of formation by partial melting with a sort of crystal fractionation dominated by clinopyroxene and Fe-Ti oxides.The latter have abundant titanomagnetite and lesser ilmenite.There is a remarkable enrichment of light rare earth elements and depletion in Ba,Th and K,Ta,and Ti.The geochemical data in this work suggest Harrat Al-Birk basalts represent products of watersaturated melt that was silica undersaturated.This melt was brought to the surface through partial melting of asthenospheric upper mantle that produced enriched oceanic island basalts.Such partial melting is the result of subducted continental mantle lithosphere with considerable mantle metasomatism of subducted oceanic lithosphere that might contain hydrous phases in its peridotites.The fractional crystallization process was controlled by significant separation of clinopyroxene followed by amphiboles and Fe-Ti oxides,particularly ilmenite.Accordingly,the Harrat Al-Birk alkali basalts underwent crystal fractionation that is completely absent in the exotic mantle xenoliths(e.g.Nemeth et al.in The Pleistocene Jabal Akwa A1 Yamaniah maar/tuff ring-scoria cone complex as an analogy for future phreatomagmatic to magmatic explosive eruption scenarios in the Jizan Region,SW Saudi Arabia 2014).
文摘Recombinant eel GH and yeast containing chinook salmon growth hormone (reGH and rcsGH) were incorporated into gelatin and sodium alginate (reGH GS and rcsGH GS) or polymer matrix (reGH HP55) to protect the hormone from proteolytic cleavage in the stomach. The diets containing reGH GS, rcsGH GS, reGH HP55 and free reGH or uncoated rcsGH were administered to red sea bream. Feeding of reGH GS, reGH HP55 and rcsGH GS diets resulted in significant increases in body weight and fork length over those of controls. These results strongly suggest that gelatin and sodium alginate as well as polymer matrix protected the hormone from proteolytic enzymes in the gastrointestinal tract to allow the bioactive hormone to enter the circulation and eventually stimulate fish growth.
文摘Knowing Moho discontinuity undulation is fundamental to understanding mechanisms of lithosphereasthenosphere interaction, extensional tectonism and crustal deformation in volcanic passive margins such as the study area, which is located in the southwestern corner of the Arabian Peninsula bounded by the Red Sea and the Gulf of Aden. In this work, a 3D Moho depth model of the study area is constructed for the first time by inverting gravity data from the Earth Gravitational Model(EGM2008) using the ParkerOldenburg algorithm. This model indicates the shallow zone is situated at depths of 20 km to 24 km beneath coastal plains, whereas the deep zone is located below the plateau at depths of 30 km to 35 km and its deepest part coincides mainly with the Dhamar-Rada ’a Quaternary volcanic field. The results also indicate two channels of hot magmatic materials joining both the Sana’a-Amran Quaternary volcanic field and the Late Miocene Jabal An Nar volcanic area with the Dhamar-Rada’a volcanic field. This conclusion is supported by the widespread geothermal activity(of mantle origin) distributed along these channels,isotopic data, and the upper mantle low velocity zones indicated by earlier studies.
基金funded by the Deanship of Scientific Research (DSR) at King Abdulaziz University under grant (No. G-389-150-36)DSR for technical and financial support
文摘Monthly abundance of the subclass Copepoda was analyzed from the zooplankton samples collected at Obhur Creek, Jeddah, Saudi Arabia during December-2011 till December-2012. Zooplankton samples were collected through surface horizontal tows by a modified WP2 net(via. mouth diameter 50 cm, length 180 cm, 150 μm mesh size). Order Calanoida dominated the abundance with mean annual average of 75.29%. We observed abnormal protuberances on copepods, known as tumour-like anomalies(TLAs). Calanoida showed more frequent and prominent TLAs on its dorsal surface with highest mean percentage occurring during Jun. 2012(1.64%). The percentage prevalence of TLAs on the Copepoda was highest during Jun. 2012(1.36%) and least during Nov. 2012(0.03%). It is suggested that these TLAs might be caused due to the presence of potentially high levels of toxic substances, which weakens the exoskeleton and thereby making them more susceptible to infections or due to wounds from parasites or might be related to the occurrence of symbiotic tantulocarids or might be due to the radiation stress as a control measure. Whatever the reason, these TLAs have become a serious emerging threat to the aquatic food web. Our investigation is the first of its kind in the coastal waters of the Saudi Red Sea, which needs further investigations in order to elucidate the possible reasons for these abnormalities.
文摘Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Triaenodon obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and</span><i> </i></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"><i></i></span></i></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Hipposcarus harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><i><span style="font-family:;" "=""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">fish were purchased from Port Sudan fish central market during December 2014. The fatty acid profiles of the livers of these commercially important fish were determined. The polyunsaturated and saturated fatty acids ratio in the livers oil of </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">H. harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> was 1:2.2 and 1:1.38, respectively. The Palmatic (16:0), Pentadecenoic (12:0) and Arachidic acids were the highest in both species. The poly chain unsaturated fatty acids Linolenic (18:3n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3), Eicosapentaenoic (20:5n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) and Docosahexaenoic (22:6n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) were detected in the liver of both species. The highest values of above poly chain unsaturated fatty acids were detected in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">.</span></i></span></span>
基金P & R Geological Consultants and the CNRS/INSU/Marges programme for funding this work
文摘Opening of the Red Sea started while the core of the lavas of the Ethiopian Large Igneous Province(LIP)was being erupted at;0 Ma(Hughes et al.,1991)and has continued to the Present.In the southern Red Sea,oceanic
文摘The aim of the paper is to present a repertory of all archaeological data about the Ayla-Axum amphorae and its content. The study of these class of material will also highlight some aspects of the Early Medieval trade, a period in which sensible political changes occurred after the fall of the Western Roman Empire. The Ayla-Axum amphorae, found in several Red Sea's sites, are significant indicators of trading activities in the region, whose production, transport and diffusion are far from having been thoroughly investigated up to now. Although most scholars think it was used to transport date wine, at least judging on some tituli picti found in these containers, in recent years Parker and Dolinka have suggested that they might have carried garum or a similar fish-sauce produced at Ayla-AqabaI.
文摘The expected water mixing process between Red/Dead Sea water during the proposed conveyance projects is the main target of this research. The project will ensue transporting Red Sea water to recover and maintain certain level of the Dead Sea, mostly will reach <span><span><span style="font-family:;" "=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">-</span></span></span></span><span style="font-family:;" "="">395</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">m. It is found that, the two different water bodies with different EC values or different densities (salinities) are relatively divided by stable plane. This plane is defined as the BARZACH PLANE. In this study, the mixing process occurred between the Red Sea with the Dead Sea waters, located at 20</span><span style="font-family:;" "="">% </span><span style="font-family:;" "="">-</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">24% of the Dead Sea column depth based on the Barzach Plane level. During a laboratory experimental work, it is found that the mixed Red/Dead Sea water evaporates in a high rate until certain level where the solution attains oversaturated conditions with different dissolved solids. At this stage, a thin layer of solids suddenly formed and floated at the surface of the dense brine. The salinity of the captured water is so dense that floated salt layer cannot be dissolved. In addition, the formed floated salt layer at the surface prevents the below captured water to evaporate and at this stage, stalactites start to form until the excess dissolved solids are not oversaturated with any mineral.</span>
文摘Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studied. The study was designed to provide base line data and information on the current socio-economic situation, factors that determine the use of fishing gear, types of boats and fishing equipment, challenges facing fishers and the extent to which fishing gear and boats are related with the socio-economic characteristics of the fishers community in the study sites. Fieldwork was carried out during 2016. The study methods included a series of interviews based on questionnaires, field observations and focus group discussions. The results of the study showed that the most common fishing gears are handlines, cast nets and gillnets. The two types of boats used at the study sites are motorized fiberglass and houri (motorized and paddled) with a V-shaped hull. Boat ownership varies among fishers. Each fisher can have several types of gears in different numbers. Target fish species, season, efficiency of gear and fishing location were the main factors determining the use of fishing gear at study sites, respectively. All fishers are men and most have families of at least four people. The majority of fishers are between 21 and 50 years old and work mainly in fishing. They inherited fishing knowledge within the family, and most of them have been working in artisanal fishing for more than 10 years. Fishers have relatively good net incomes compared to other government employers in the study sites. Most fishers work full time in fishing. A small number of fishers work part-time with the possibility of undertaking other income-generating activities such as animal husbandry and seasonal agriculture. The main challenges identified by fishers at the study sites were fish prices, sea surface roughness and high cost of fishing materials, respectively. Most fishers perceived a recent decline in both catch size and abundance.