Search Results (23)

The UNESCO World Heritage Centre announced in 2011 that the Wadi Rum Protected Area (WRPA) is a global landmark for natural and cultural attraction, which represents an emerging industrial suburban and a critical socio-economic significance to the country of Jordan. The study area in Wadi Rum is located northeast of the Gulf of Aqaba between the African and Arabian plates. The region is historically characterized by significant tectonic activity and seismic events. This study focuses on characterizing the subsurface structural features of Wadi Rum through the application of the geophysical method of controlled-source audio-frequency magnetotellurics (CSAMT). CSAMT data were collected from 16 sounding stations, processed, and qualitatively interpreted. The qualitative interpretation involved two main approaches: constructing sounding curves for each station and generating apparent resistivity maps at fixed depths (frequencies). The results revealed the presence of at least four distinct subsurface layers. The surface layer exhibited relatively low resistivity values (<200 Ω·m), corresponding to alluvial and wadi sediments, as well as mud flats. Two intermediate layers were identified: the first showed very low resistivity values (80–100 Ω·m), likely due to medium-grained bedded sandstone, while the second displayed intermediate resistivity values (100–800 Ω·m), representing coarse basal conglomerates and coarse sandstone formations. The deepest layer demonstrated very high resistivity values (>1000 Ω·m), which were likely attributed to basement rocks. Analysis of resistivity maps, combined with prior geological information, indicates that the subsurface in the study area features a graben-like structure, characterized by two detected faults trending in the northeast (NE) and southwest (SW) directions. The findings of this study, by providing critical insights into the subsurface structure, make a considerable contribution to the urban sustainability of the region, which is necessary for the careful assessment of potential hazards and the strategic planning of future infrastructure development within the protected area. Full article

The Ayla Oasis in Aqaba, Jordan, is a major tourism and residential development project in Aqaba, Jordan, containing three artificial lagoons. This study explores the ecological sustainable development of Ayla Lagoons, focusing on the seawater and bottom sediment quality, and the bottom habitat, in addition to coral conservation and restoration initiatives. The flushing time, averaging 3.7 days for the Upper Lagoon and 2.4 days for the Middle Lagoon, plays a crucial role in maintaining water quality. These measures secure the well-being of all visitors and residents, while also preserving the marine biodiversity. The Upper, Middle, and Tidal Lagoons exhibit physiochemical properties in alignment with seawater characteristics of the Gulf of Aqaba. Sediment quality analysis shows organic carbon levels and grain size distribution vary among lagoons, indicating expected different energy conditions and a healthy environment. The lagoons support a diverse range of species, with a total of 2343 fish individuals belonging to 22 species across 17 families recorded. The comprehensive analysis of the Ayla Oasis lagoons’ seawater and sediment quality revealed a dynamic and resilient ecosystem. Ayla’s coral conservation and restoration initiative within its lagoons feature 166 reef balls, 5 coral nurseries, and 2 metal structures, all designed to foster marine biodiversity. The project demonstrates the effectiveness of Ayla Oasis’ environmental resilience and monitoring strategies, showcasing a commitment to sustainable management and environmental stewardship. These efforts reflect Ayla’s ongoing dedication to protecting and preserving the marine ecosystem, ensuring the long-term health of its coral reefs and surrounding marine life. Full article

Egyptian Red Sea fisheries face the same challenges as most of the world’s fisheries, including overexploitation, habitat loss, IUU fishing, pollution, and climate change. These fisheries are highly diverse with multiple species targeted by multiple fleets, using different fishing gears. Much work has been performed in recent years to assess Red Sea fish stocks. However, not all fish stocks in the Egyptian Red Sea are assessed, and those that are assessed only cover 30% of landings. The assessments are unbalanced by area, with the Gulf of Suez being much better covered than the southern Red Sea and Gulf of Aqaba. The results show that most of the analyzed stocks are overexploited. There is an urgent need to take action to protect, conserve, and restore the different fish stocks in different fishing grounds. These actions will ensure the sustainability of the fisheries, making them ecologically friendly and economically and socially efficient. Full article

A comprehensive geostatistical analysis was conducted on a dataset comprising 24,321 seismic events in the Red Sea region, spanning from 1997 to 2020. This analysis involved the creation of a new seismic activity database, incorporating data from both Egyptian and Saudi Seismic Networks. This enriched database provided a robust foundation for a detailed examination of the seismic patterns and activities in the region. Utilizing geographic information systems and various spatial analytic methods, it identifies seismic patterns and tectonic influences. The findings reveal significant seismic clustering along the Central Red Sea axis, indicative of active rifting between the Nubian and Arabian plates. The study demonstrates spatial autocorrelation in seismic activities, with high-high clusters marking zones of elevated seismicity. Kernel Density Estimator analyses highlight concentrated seismic activity in the Gulfs of Aqaba and Suez. Higher magnitude events are shown to localize in areas of greater tectonic stress, aligning with known geological features. This research provides critical insights into the seismic dynamics of the Red Sea, showcasing the effectiveness of geostatistical techniques in analyzing seismic data in tectonically active regions. Full article

Traveltime picking accuracy is frequently affected by incoherent or random data noise. Within this context, we put forth a new denoising method called iterative interferometric denoising filtering. This method leverages the pseudo-Wigner distribution function to capture the offset and time-symmetric patterns of source wavelets convolved in seismic signals. Incoherent or random noises without this characteristic are eliminated via this approach. The processed data have waveform information distortion and more frequency components. However, the traveltime information can be considered correct, and the improved signal-to-noise ratio makes traveltime picking much more convenient. Our method’s practical applications in a synthetic and in two field datasets show that this technology can increase the signal-to-noise ratio, and the picked traveltime information can be used in traveltime tomography. These two field datasets were collected near the Aqaba Gulf and the Qademah fault, located in King Abdullah Economic City. Full article

Coral nurseries and associated techniques are the most common and widespread reef restoration methods worldwide. Due to the rapid decline of coral reefs, coral nurseries need to be eco-friendlier and adapted for effective upscaling to support large restoration projects. We suggest new design and fabrication processes associated with coral gardening and transplantation with 3D printing technology to offer a beneficial solution for growing coral fragments in on-land and underwater nurseries. We describe multiple combinations of building nurseries through the integration of biomimetic substrates and novel solutions for attaching coral fragments. Our methods are supported with supplemental testing of two hybrid substrate designs and coral mounting structures, building upon previous studies in the Gulf of Eilat/Aqaba (GoE/A), Red Sea. We identified and quantified marine invertebrates colonizing the surfaces of our substrates with environmental DNA (eDNA) by targeting the mitochondrial COI gene. We evaluated our coral fragments with and without our mounting structures to obtain an indication of total protein as a proxy for tissue health. We demonstrate the ability to design hybrid nurseries with custom mounting structures using biomimetic substrates, such as large ceramic artificial reefs, or with an interlocking mesh for holding numerous fragments to maximize out-planting efforts. We propose several methods for both land and underwater nurseries catered to various restoration initiatives for cost-effective up-scaling to meet the demands of global reef restoration. Full article

Identifying areas susceptible to flash flood hazards is essential to mitigating their negative impacts, particularly in arid regions. For example, in southeastern Sinai, the Egyptian government seeks to develop its coastal areas along the Gulf of Aqaba to maximize its national economy while preserving sustainable development standards. The current study aims to map and predict flash flood prone areas utilizing a spatial analytic hierarchy process (AHP) that integrates GIS capabilities, remote sensing datasets, the NASA Giovanni web tool application, and principal component analysis (PCA). Nineteen flash flood triggering parameters were initially considered for developing the susceptibility model by conducting a detailed literature review and using our experiences in the flash food studies. Next, the PCA algorithm was utilized to reduce the subjective nature of the researchers’ judgments in selecting flash flood triggering factors. By reducing the dimensionality of the data, we eliminated ten explanatory variables, and only nine relatively less correlated factors were retained, which prevented the creation of an ill-structured model. Finally, the AHP method was utilized to determine the relative weights of the nine spatial factors based on their significance in triggering flash floods. The resulting weights were as follows: rainfall (RF = 0.310), slope (S = 0.221), drainage density (DD = 0.158), geology (G = 0.107), height above nearest drainage network (HAND = 0.074), landforms (LF = 0.051), Melton ruggedness number (MRN = 0.035), plan curvature (PnC = 0.022), and stream power index (SPI = 0.022). The current research proved that AHP, among the most dependable methods for multi-criteria decision-making (MCDM), can effectively classify the degree of flash flood risk in ungauged arid areas. The study found that 59.2% of the area assessed was at very low and low risk of a flash flood, 21% was at very high and high risk, and 19.8% was at moderate risk. Using the area under the receiver operating characteristic curve (AUC ROC) as a statistical evaluation metric, the GIS-based AHP model developed demonstrated excellent predictive accuracy, achieving a score of 91.6%. Full article

The Midyan Terrane (northwest Saudi Arabia) is characterized by the presence of a massive belt of radioactive granitic rocks and thick sedimentary cover near the coastal areas. The area is greatly influenced by the tectonic activities of the Red Sea and Gulf of Aqaba, implying its high potentiality of geothermal energy. In the present work, geophysical surveys, including audio magnetotelluric and gravity methods, were integrated to investigate the subsurface structural pattern of the study area, which identified regional deep and shallow fault systems and detected the subsurface geometry/extension of the granitic rocks as well as detecting the thickness of the sedimentary basins near the coastal area. A total number of 80 audio magnetotelluric and 246 gravity stations were recorded, analyzed, and interpreted. Two high-potential geothermal targets were indicated: high-heat-generating granites and thick anomalous sedimentary basins near the coastal areas. High-heat-generating granites are significant in terms of enhanced geothermal systems (EGSs) whereas sedimentary basins play a crucial role in the formation of conventional geothermal systems. Both areas require more exploration plans to evaluate the energy potential of geothermal reservoirs. The results also contribute to the identification of the subsurface orientation and geometry of radioactive granites, providing the necessary parameters to enhance a volumetric estimation for geothermal reserves. Full article

The Saudi Arabia government announced the $500 billion mega project “NEOM City”, to build a cross-border mega city to connect Saudi Arabia, Egypt, and Jordon for attracting foreign investments to the region. NEOM city is situated on the eastern region of the Gulf of Aqaba with its western side in the Sinai Peninsula. The selected site for NEOM city is geographically remarkable; nevertheless, this site needs a detailed geological and geophysical investigation. Sinai Peninsula is a microplate between the Arabian and African plates. Its southern tip is located at a triple junction comprising the Gulf of Aqaba–Dead Sea Transform fault, the Gulf of Suez, and the Red Sea, leading to relatively higher seismic activities in the region. The current study aims to understand the thermal structure of the vicinity of NEOM city to address the potential geohazards and indicate geological attractions within and around the planned city. We use the magnetic data from which geothermal images can be obtained. The preliminary results indicate that there is geologic similarity between the southern part of Sinai Peninsula and the northern part of the Arabian shield. This is because the Gulf of Aqaba separates what was once a continues Neoproterozoic crust. In addition, the magnetic data showed the presence of prominent lineaments on either side of the Gulf of Aqaba. The notable lineaments might represent faults that could still be active. Hence, selecting a site of NEOM city to be east of the Gulf of Aqaba needs to be guided by the careful understanding of the potential hazards. In addition, shallow Curie depths near the Gulf of Aqaba are recognized as a source for renewable geothermal energy. Full article

Located at the northern tip of the Red Sea, the Gulf of Aqaba coral reef is highly susceptible to anthropogenic pressure associated with the massive development of the two neighboring cities of Eilat and Aqaba. Over the years, the reef has been extensively studied in a number of research and monitoring programs, which provide detailed information on a variety of ecological, physiological, biogeochemical and physical variables. Due to the local nature of these surveys, although the state of the reef at specific times and locations is very well characterized, long-term changes in the spatial characteristics of the reef as a whole have not yet been quantified. Here, through analysis of historical aerial images, we address one of the most important aspects of this knowledge gap and quantify the decrease in coral reef coverage, with respect to a baseline level prior to the establishment of the City of Eilat in 1949. Our results show that along a 8460 m segment of the shoreline at the northwestern edge of the GOA (29°29′–30°N/34°54′–35°E), infrastructure construction has led to the loss of more than 4810 m² of coral reef. This loss has been caused either directly by the construction (most importantly the Eilat Port) or indirectly by changing environmental conditions, which in turn damage the reef. Our results show that historical aerial images can provide a unique source of information on the spatial characteristics of marine and coastal systems prior to the era of Earth observation satellites. Full article

The historic environment of north-west Saudi Arabia is likely to be severely impacted by the construction of the Neom mega-city complex and the development of the city’s hinterland. This region, located east of the Gulf of Aqaba, has only been subject to limited archaeological survey in the past, limiting any assessment of this negative impact. This paper presents data collected through a remote sensing survey of the region undertaken by the Endangered Archaeology in the Middle East and North Africa (EAMENA) project, independent of the Neom project. It is argued that this data reflects a landscape of movement between north and south, with evidence of structures and monuments from at least the Bronze Age through to the pre-Islamic period, but little evidence of permanent settlement or agriculture. This should not be dismissed as a peripheral landscape, but one that contains rich archaeological evidence of concentrated activity, suggesting that some areas have held long-term significance to the people inhabiting and moving through this region. Full article

The global continued decline in coral reefs is intensifying the need to understand the response of corals to local environmental stressors. Coral-associated bacterial communities have been suggested to have a swift response to environmental pollutants. This study aims to determine the variation in the bacterial communities associated with the mucus of two coral species, Pocillopora damicornis (Linnaeus, 1758) and Stylophora pistillata (Esper, 1792), and the coral-surrounding seawater from three areas exposed to contamination at the Jordanian coast of the Gulf of Aqaba (Red Sea), and also explores the antibacterial activity of these bacteria. Corals were collected from three contaminated zones along the coast, and the bacteria were quantified and identified by conventional morphological and biochemical tests, as well as 16S rRNA gene sequencing. The average number of bacteria significantly varied among the coral mucus from the sampling zones and between the coral mucus and the surrounding seawater. The P. damicornis mucus-associated bacterial community was dominated by members of the classes Gammaproteobacteria, Cytophagia, and Actinomycetia, while the mucus of S. pistillata represented higher bacterial diversity, with the dominance of the bacterial classes Gammaproteobacteria, Actinomycetia, Alphaproteobacteria, and Bacilli. The effects of local anthropogenic impacts on coral mucus bacterial communities were represented in the increased abundance of bacterial species related to coral diseases. Furthermore, the results demonstrated the existence of bacterial isolates with antibacterial activity that possibly acted as a first line of defense to protect and maintain the coral host against pathogens. Indeed, the dynamics of coral-associated microbial communities highlight the importance of holistic studies that focus on microbial interactions across the coral reef ecosystem. Full article

The Gulf of Aqaba (GoA), positioned between the Sinai Peninsula and the Saudi Arabian coast is characterized by its uniquely high saline, oligotrophic waters, and seasonally stratified hydrography. Despite its geographical significance, information on its zooplankton ecology and biodiversity is still meager. Hence, the present study was aimed to investigate the detailed diversity and ecology of the dominant carnivorous zooplankton taxon chaetognath in the pelagic waters of the GoA during summer. Despite the known water flow exchange between the GoA and the Red Sea, only five chaetognath species were observed in GoA which is markedly less than the number earlier recorded in the Red Sea, indicating the role of high saline water mass as an ecophysiological boundary for the inhabitance of many epipelagic chaetognaths. Euryhaline, Serratosagitta pacifica formed the dominant species in both the surface water and the upper 200 m water column and was observed to be the most suitable representative of this high saline environment. Conspicuous diel variability in the distribution of the different growth stages of chaetognaths in the surface waters can be attributed to their varied susceptibility to visually oriented predators. The positive relation observed in the abundance of chaetognaths and their main prey, copepods, and their carbon and nitrogen contents indicated their significance in the pelagic trophic ecology of the GoA. The present study, providing the ecology of a major zooplankton taxon of this unique basin will be relevant for understanding the ecology and trophodynamics of the zooplankton community of the GoA. Full article

Bioactive compounds extracted from marine organisms showed several biological activities. The present study is an extension of our earlier studies where we assessed the antiproliferative and pro-apoptotic activities of ethanol, methylene chloride, ethyl acetate, acetone, and chloroform crude extracts of sponges: Negombata magnifica (NmE) and Callyspongia siphonella (CsE) against cancer cells. Herein, we are extending our previous findings on both sponge species depending on an alternative methanol extraction method with more advanced molecular biochemical insights as additional proof for anticancer and antimicrobial activity of N. magnifica and C. siphonella. Therefore, sponge specimens were collected during winter 2020 from the Dahab region at the Gulf of Aqaba. Each sponge was macerated with methanol to obtain the crude extracts; NmE and CsE. GC–MS analysis presented a total of 117 chemical compounds; 37 bioactive, 11 represented previously as constituents for a natural organism, and 69 had no biological activities. NmE dose-dependently inhibited the growth of HepG2, MCF-7, and Caco-2 carcinoma cell lines compared to CsE, which unfortunately has no antiproliferative activity against the same cancer cells. NmE was found to induce G0/G1 cell cycle arrest in HepG2 cells with its inhibition for CDK6, Cyclins D1, and E1 in HepG2, MCF-7, and Caco-2 cells. NmE also activated ROS production in HepG2 cells and induced apoptosis in HepG2, MCF-7, and Caco-2 cells via an increase in pro-apoptotic protein Bax, caspase-3, and cleavage PARP, and a decrease in anti-apoptotic protein BCL2. Unlike its anticancer potential, CsE exhibited clear superior results as an antimicrobial agent with a wider range against six microbial strains, whereas NmE showed a positive antibacterial activity against only two strains. Full article

Theonella swinhoei is a fairly common inhabitant of reefs throughout the Indian and Pacific Oceans. Metabolomic analyses of samples of T. swinhoei collected in different depths in the Gulf of Aqaba revealed two chemotypes differing in the profiles of the theonellamides they produce, some of which seem to be unknown. Driven by this finding, we examined a sample of T. swinhoei collected more than 40 years ago in the southern part of the Gulf of Aqaba. Large-scale extract of this sample yielded four theonellamides, the known theopalauamide (4), as the major component, and three new metabolites, theonellamide J (1), 5-cis-Apoa-theopalauamide (2), and theonellamide K (3), as the minor components. The planar structure of these complex cyclic glycopeptides was elucidated by combination of 1D and 2D NMR techniques and HRESIMS. The absolute configuration of the amino acids was established by Marfey’s and advanced Marfey’s methods, and the absolute configuration of its galactose unit using “Tanaka’s method” for monosaccharides. The biological activity of the pure compounds was tested for antibacterial activity and for cytotoxicity to HTC-116 cell line. The compounds presented significant cytotoxicity against the HTC-116 cell line, illuminating the importance of the Apoa subunit for the activity. Full article