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Rapid ocean warming due to climate change poses a serious risk to the survival of coral reefs. It is estimated that 70–90 percent of all reefs will be severely degraded by mid-century even if the 1.5°C goal of the Paris Climate Agreement is achieved. However, one coral reef ecosystem seems to be more resilient to rising sea temperatures than most others. The Red Sea’s reef ecosystem is one of the longest continuous living reefs in the world, and its northernmost portion extends into the Gulf of Aqaba. The scleractinian corals in the Gulf have an unusually high tolerance for the rapidly warming seawater in the region. They withstand water temperature anomalies that cause severe bleaching or mortality in most hard corals elsewhere. This uniquely resilient reef employs biological mechanisms which are likely to be important for coral survival as the planet’s oceans warm. The Gulf of Aqaba could potentially be one of the planet’s largest marine refuges from climate change. However, this unique portion of the Red Sea’s reef will only survive and flourish if serious regional environmental challenges are addressed. Localized anthropogenic stressors compound the effects of warming seawater to damage corals and should be mitigated immediately. Reefs in the rest of the Red Sea are already experiencing temperatures above their thermal tolerance and have had significant bleaching, though they too would benefit from fewer local anthropogenic stressors. The countries bordering the entire Red Sea will need to cooperate to enable effective scientific research and conservation. The newly established Transnational Red Sea Center, based at the Ecole Polytechnique Fédérale de Lausanne (EPFL), can serve as the regionally inclusive, neutral organization to foster crucial regional scientific collaboration. published

Near-surface geophysical imaging of alluvial fan settings is a challenging task but crucial for understating geological processes in such settings. The alluvial fan of Ghor Al-Haditha at the southeast shore of the Dead Sea is strongly affected by localized subsidence and destructive sinkhole collapses, with a significantly increasing sinkhole formation rate since ca. 1983. A similar increase is observed also on the western shore of the Dead Sea, in correlation with an ongoing decline in the Dead Sea level. Since different structural models of the upper 50 m of the alluvial fan and varying hypothetical sinkhole processes have been suggested for the Ghor Al-Haditha area in the past, this study aimed to clarify the subsurface characteristics responsible for sinkhole development. For this purpose, high-frequency shear wave reflection vibratory seismic surveys were carried out in the Ghor Al-Haditha area along several crossing and parallel profiles with a total length of 1.8 and 2.1 km in 2013 and 2014, respectively. The sedimentary architecture of the alluvial fan at Ghor Al-Haditha is resolved down to a depth of nearly 200 m at a high resolution and is calibrated with the stratigraphic profiles of two boreholes located inside the survey area. The most surprising result of the survey is the absence of evidence of a thick (> 2–10 m) compacted salt layer formerly suggested to lie at ca. 35–40 m depth. Instead, seismic reflection amplitudes and velocities image with good continuity a complex interlocking of alluvial fan deposits and lacustrine sediments of the Dead Sea between 0 and 200 m depth. Furthermore, the underground section of areas affected by sinkholes is characterized by highly scattering wave fields and reduced seismic interval velocities. We propose that the Dead Sea mud layers, which comprise distributed inclusions or lenses of evaporitic chloride, sulfate, and carbonate minerals as well as clay silicates, become increasingly exposed to unsaturated water as the sea level declines and are consequently destabilized and mobilized by both dissolution and physical erosion in the subsurface. This new interpretation of the underlying cause of sinkhole development is supported by surface observations in nearby channel systems. Overall, this study shows that shear wave seismic reflection technique is a promising method for enhanced near-surface imaging in such challenging alluvial fan settings. Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 979

Giant clams are among the most spectacular but also the most endangered marine invertebrates. Their large size and easy accessibility has caused overfishing and collapse of the natural stocks in many places and local extinction in some of the species 1 and 2. The diversity of giant clams is extremely low because of reliction in this Tethyan group 3 and 4. The latest additions of living species date back almost two decades 5, 6 and 7, fixing the number of extant Tridacna at seven species [3]. Here, we report the discovery of a new species of giant clam: Tridacna costata sp. nov. features characteristic shells with pronounced vertical folds, is genetically distinct, and shows an earlier and abbreviated reproduction than its Red Sea congeners. This species represents less than 1% of the present stocks but up to >80% of the fossil shells. The decline in proportion and shell size (20×) indicates overharvesting [8] dating back to the early human occupation of the Red Sea >125,000 years ago [9]. This earliest depletion reported so far of a shallow-water megafaunal invertebrate has important ramifications for human dispersal out of Africa [10]. Its oversight in one of the best-investigated reef provinces 11, 12 and 13 illustrates the dearth of knowledge on marine biodiversity.

The COVID-19 pandemic has produced an unprecedented change in the educational system worldwide. Besides the economic and social impacts, there is a dilemma of accepting the new educational system ''e-learning'' by students within educational institutions. In particular, universities students have to handle several kinds of environmental, electronic and mental struggles due to COVID-19. To catch the current circumstances of more than two hundred thousand Jordanian university student during COVID-19. The students have been randomly selected to respond on an online survey using universities' portals and websites between March and April 2020. At the end of the data gathering process, we have received 587 records. The dataset includes 1) Demographics of students; 2) students’ perspectives concerning the factors influencing their intention to use e-learning system within the Jordanian universities context. Data were analyzed using Partial Least Squares - Structural Equation Modelling (PLS-SEM). Next, the result has confirmed the positive of direct effect variables (subjective norm, perceived ease of use, and perceived usefulness) on the students’ intention to use e-learning system. Next, the result has also confirmed the mediating effect of perceived usefulness and perceived ease of use between subjective norm and the behavioral intention to use the e-learning system with partially supported.

210 Po and 210 Pb activity concentrations and their concentration ratio (CR) in marine zooplankton collected for the first time from the Syrian coastal waters (the eastern Mediterranean Sea) have been determined. The average activity concentrations of 210 Po and 210 Pb were 243±36 and 26.4±4.3 Bqkg -1 dw. The 210 Po/ 210 Pb activity ratio was found to be more than one in all zooplankton samples with an average of 9.2 (8.4 to 10), which indicates that the accumulation of 210 Po in zooplankton does not come from the decay of the 210 Pb only, and reflects a preferential bioaccumulation of 210 Po over 210 Pb. In addition, the Concentration Ratio (CR) for 210 Po and 210 Pb reached 10 4 and 10 3 , respectively. This study will contribute to the radioecological reference database for zooplankton in the Mediterranean Sea.

Identifying and quantifying nitrogen pools is essential for understanding the nitrogen cycle in aquatic ecosystems. The ubiquitous diatoms represent an overlooked nitrate pool as they can accumulate nitrate intracellularly and utilize it for nitrogen assimilation, dissipation of excess photosynthetic energy, and Dissimilatory Nitrate Reduction to Ammonium (DNRA). Here, we document the global co-occurrence of diatoms and intracellular nitrate in phototrophic microbial communities in freshwater (n = 69), coastal (n = 44), and open marine (n = 4) habitats. Diatom abundance and total intracellular nitrate contents in water columns, sediments, microbial mats, and epilithic biofilms were highly significantly correlated. In contrast, diatom community composition had only a marginal influence on total intracellular nitrate contents. Nitrate concentrations inside diatom cells exceeded ambient nitrate concentrations similar to 100-4000-fold. The collective intracellular nitrate pool of the diatom community accounted for <1% of total nitrate in pelagic habitats and 65-95% in benthic habitats. Accordingly, nitrate-storing diatoms are emerging as significant contributors to benthic nitrogen cycling, in particular through Dissimilatory Nitrate Reduction to Ammonium activity under anoxic conditions. The accumulation and storage of nitrate by diatoms can contribute up to 1% of total pelagic nitrate and as much as 95% of total benthic nitrate, which indicates a potentially important contribution of diatoms to benthic nitrogen cycling, according to a global analysis

Butana and Kenana are two types of zebu cattle found in Sudan. They are unique amongst African indigenous zebu cattle because of their high milk production. Aiming to understand their genome structure, we genotyped 25 individuals from each breed using the Illumina BovineHD Genotyping BeadChip. Genetic structure analysis shows that both breeds have an admixed genome composed of an even proportion of indicine (0.75 ± 0.03 in Butana, 0.76 ± 0.006 in Kenana) and taurine (0.23 ± 0.009 in Butana, 0.24 ± 0.006 in Kenana) ancestries. We also observe a proportion of 0.02 to 0.12 of European taurine ancestry in ten individuals of Butana that were sampled from cattle herds in Tamboul area suggesting local crossbreeding with exotic breeds. Signatures of selection analyses (iHS and Rsb) reveal 87 and 61 candidate positive selection regions in Butana and Kenana, respectively. These regions span genes and quantitative trait loci (QTL) associated with biological pathways that are important for adaptation to marginal environments (e.g., immunity, reproduction and heat tolerance). Trypanotolerance QTL are intersecting candidate regions in Kenana cattle indicating selection pressure acting on them, which might be associated with an unexplored level of trypanotolerance in this cattle breed. Several dairy traits QTL are overlapping the identified candidate regions in these two zebu cattle breeds. Our findings underline the potential to improve dairy production in the semi-arid pastoral areas of Africa through breeding improvement strategy of indigenous local breeds.