El impacto de las inundaciones y las tormentas de arena en el crecimiento y la supervivencia de las plántulas del manglar Avicennia marina en el sur del Mar Rojo

Mangroves occur in tropical and subtropical regions, including harsh arid areas. Little is known about how the environmental conditions of deserts influence the ecology of mangrove seedlings. The seedlings of the mangrove Avicennia marina were examined in situ in a natural stand of the southern Red Sea coast of Saudi Arabia to (1) estimate and compare the growth rate of A. marina between selected microhabitats with different tidal exposures, and (2) examine the influence of sandstorms on the growth and survival of the seedlings. Samplings were conducted in four zones established according to their tidal exposure: low tidal exposure (Z1), medium tidal exposure (Z2), high tidal exposure with numerous burrows (Z3), and high tidal exposure with a few or no burrows (Z4). Vertical growth and mortality of the seedlings and selected environmental variables were quantified. The results show that seedling growth rates differed significantly between the sampling zones, the highest growth being found in the high tidal regions (Z3 followed by Z4) and the lowest growth in Z1. Growth rate followed a significant decreasing pattern over time, coinciding with increasing air temperature and decreasing relative humidity. Sandstorms showed a marked increase in July, leading to massive dust deposition that caused extensive mortality of the seedlings by burial. Our study highlights that seedling growth can be affected by the extent of tidal inundation and that sandstorms act as a natural stressor.Los manglares proliferan en regiones tropicales y subtropicales, incluidos los desiertos. Sin embargo, se sabe poco acerca de cómo las condiciones ambientales de los desiertos influyen en la ecología de las plántulas de manglares. Las plántulas del manglar Avicennia marina se examinaron in situ en un manglar natural de la costa sur del Mar Rojo de Arabia Saudita para (1) estimar y comparar la tasa de crecimiento de A. marina entre microhábitats seleccionados con diferente exposición a las mareas, y (2) examinar la influencia de las tormentas de arena en el crecimiento y supervivencia de las plántulas. Los muestreos se realizaron en cuatro zonas establecidas en función de su exposición a las mareas: exposición a las mareas bajas (Z1), exposición a las mareas medias (Z2), exposición a las mareas altas con numerosas madrigueras de cangrejos (Z3) y exposición a las mareas altas pero con pocas o ninguna madriguera (Z4). Se cuantificó el crecimiento vertical y la mortalidad de las plántulas, así como las variables ambientales seleccionadas. Los resultados muestran que las tasas de crecimiento de las plántulas difirieron significativamente entre las zonas de muestreo con el mayor crecimiento encontrado en las regiones de marea alta (Z3 seguida de Z4) y el crecimiento más bajo en Z1. La tasa de crecimiento siguió un patrón decreciente significativo a lo largo del tiempo, que coincidió con el aumento de la temperatura del aire y la disminución de la humedad relativa. Las tormentas de arena aumentaron en julio, causando una deposición masiva de polvo que enterró a las plántulas, desencadenando una gran mortalidad. Nuestro estudio destaca que el crecimiento y la supervivencia de las plántulas pueden verse afectados por la extensión de la inundación de las mareas y las tormentas de arena, actuando como factores de estrés natural

Diversity, distribution, and density of marine mammals along the Saudi waters of the Arabian Gulf: update from a multi-method approach

Despite the important role of marine mammals in marine ecosystems and the imperative for their conservation, there is still a great lack of information on the diversity, distribution, and density of these animals in the Saudi waters of the Arabian Gulf. To fill this gap, an integrative data-collection approach including fishermen’s questionnaires, opportunistic sighting reports, and directed boat-based surveys, was undertaken between 2016 and 2020, leading to the first scientific report of marine mammal diversity, distribution, and density in the region. The results of the different approaches carried out during the study confirmed a high diversity of cetaceans on the west coast of the study area, with bottlenose dolphins (Tursiops aduncus), humpback dolphins (Sousa plumbea) and dugongs (Dugong dugon) as the most common species. While the two dolphin species were found to be widely distributed in both coastal and offshore waters, D. dugon appears to occur exclusively in coastal waters in the southern part of the study area, mainly in the Gulf of Salwah. The presence of both species of dolphins increased during the summer months and in the vicinity of the numerous oil and gas facilities in this region. The distribution of the observed dolphins was found mostly within a 10–20 km radius around each facility. Other cetacean species observed less frequently in the area include Bryde’s whale (Balaenoptera edeni), killer whale (Orcinus orca), common dolphin (Delphinus delphis) and finless porpoise (Neophocaena phocaenoides). Regarding the density of marine mammals in the region, boat-based surveys confirmed the results of fishermen’s questionnaires and reports of opportunistic sightings, with bottlenose and humpback dolphins being the most abundant species. These results provide a baseline for policies oriented to the conservation of mammals in the Saudi waters of the Arabian Gulf.info:eu-repo/semantics/publishedVersio

Impact of Prolonged use of Video Gaming on Grip and Pinch Strength in Young Adult

Background Video gaming has become an increasingly popular and globally recognized phenomenon in recent years While playing there are multi repetitive movements of the fingers which may lead to significant hand grip or pinch grip problems Purposes The purpose of this study was to investigate the effect of prolonged use of video games on the grip and pinch strength Materials and Methods Forty male students from King Abdulaziz University participated in this study their age ranged from 18-24 years They were divided into two groups prolonged user and non- user group The hand grip and pinch strength for all participants were measured by a handheld dynamometer and the level of video game addiction was assessed by Game Addiction Test Results There was a significant decrease in hand grip strength of the prolonged user group compared with non-user group while there was a non-significant difference between both groups in the pinch strength The result showed a nonsignificant correlation between hours of playing and Video game addiction Teat VAT with hand grip strength and pinch strength Conclusion There was a significant decrease in hand grip strength of the prolonged users of video games while there was a non-significant decrease in the pinch strength in the prolonged user group compared with non- user grou

Factors governing the deep ventilation of the Red Sea

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 120 (2015): 7493–7505, doi:10.1002/2015JC010996.A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red Sea. Historical and recent hydrographic data consistently indicate that the ventilation of the near-bottom layer in the Red Sea is a robust feature of the thermohaline circulation. Dense water capable to reach the bottom layers of the Red Sea can be regularly produced mostly inside the Gulfs of Aqaba and Suez. Occasionally, during colder than usual winters, deep water formation may also take place over coastal areas in the northernmost end of the open Red Sea just outside the Gulfs of Aqaba and Suez. However, the origin as well as the amount of deep waters exhibit considerable interannual variability depending not only on atmospheric forcing but also on the water circulation over the northern Red Sea. Analysis of several recent winters shows that the strength of the cyclonic gyre prevailing in the northernmost part of the basin can effectively influence the sea surface temperature (SST) and intensify or moderate the winter surface cooling. Upwelling associated with periods of persistent gyre circulation lowers the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme heat loss by the sea surface. In addition, the occasional persistence of the cyclonic gyre feeds the surface layers of the northern Red Sea with nutrients, considerably increasing the phytoplankton biomass.Saudi ARAMCO Marine Environmental Centre of King Abdullah University of Science and Technology (KAUST); Saudi Aramco Oil Co.2016-05-1

New depth records and novel feeding observations of three elasmobranchs species in the Eastern Red Sea

Understanding the vertical distribution of elasmobranch species and associated ecological dynamics can be a crucial component of developing effective conservation strategies, particularly in light of their global population decline. Previous studies have primarily focused on horizontal extent and movement patterns of elasmobranchs, with limited knowledge about their vertical distribution. This knowledge gap stems from limited access to technological advancements and reliance on surface data from fisheries operations. Today, advancements in observing platforms such as electronic tracking, remotely operated vehicles and submersibles, and reductions in costs for drop cameras and BRUVs, allow for direct observation of animals at great depths, facilitating improved understanding of their ecological and trophic niches. This study reports new global depth records for three elasmobranch species observed in the Saudi Arabian Red Sea (Carcharhinus altimus, Rhinobatos punctifer, Iago omanensis), also presenting ethological evidence on Iago omanensis feeding behavior. Our findings have significant implications for conservation strategies and the development of targeted conservation measures. The provisioning of data on new depth ranges allows places like NEOM to better manage and protect deep sea habitats, due to the presence of species occurring at those depths

An investigation of factors influencing the spatial and temporal distribution of surface phytoplankton in the English Channel and Bay of Biscay in 2003 and 2004

Throughout 2003 and 2004 continuous autonomous observations of surfacetemperature, conductivity and chlorophyll fluorescence were recorded on the P&O"Pride of Bilbao" ferry between Portsmouth, UK and Bilbao Spain. Different conditionsover the shelf, slope and deep waters along the route were detected and studied - fromeutrophic harbour waters to the southern Bay of Biscay, which is oligotrophic insummer. During the two years, 21 manned crossings on the ferry provided informationon nutrients, phytoplankton biomass and speciation. Measurements include chlorophylla concentrations (calibration of the fluorimeter is discussed), High Performance LiquidChromatography (HPLC) determined pigments concentrations, phytoplankton speciesabundance (biomass and identification) and nutrients. Data was also available fromsatellite images for estimates of chlorophyll (SeaWIFS), zooplankton abundance fromCPR (Continuous Plankton Recorder) tows, wind speed and direction and irradiance.This has enabled phytoplankton populations to be related to-: (1) nutrient supply (2)grazing pressure (3) fresh water influences, (4) hydrography and (5) climatic conditions.The distributions of hydrographic properties and of plankton were analysed on the basisof four generalised regions (i) well-mixed, (ii) northern summer stratified, and (iii)southern summer stratified on the shelf and (iv) oceanic region in the Bay of Biscaywater. There were differences between the two years in the timing of seasonal changesand in the abundance of phytoplankton species. Chlorophyll a values were generallyhigher in shelf waters compared to oceanic water in both years.The spring phytoplankton bloom reached its peak during March 2003 in the Bay ofBiscay and during April on the continental shelf with maximum chlorophyll values of 2-4 mg m-3. Whereas, the strong SW wind in Bay of Biscay in winter 2004 may havedelayed growth in this region. In the shelf regions in 2004 low salinity values offwestern France and high solar irradiance in the north are likely to have led to earlierphytoplankton biomass than in 2003. During early summer, the coccolithophore,Emiliania huxlyei (>1000 cells ml-1) was widespread in northern stratified regions, moreso in 2003 than in 2004. In the summer of 2003 an exceptional dinoflagellate bloomoccurred in the western English Channel. The bloom was composed of a monspecificsurface population of Karenia mikimotoi, giving cell densities up to 8000 cells ml-1 andchlorophyll a concentrations up to 70 mg m-3. Development of this dinoflagellate bloomin the western English Channel could be explained in terms of physical stability, andiilow wind speed together with sufficient light and a supply of inorganic nutrientsfavouring growth of the cells. By contrast, in 2004, the abundance of diatoms washigher than 2003 and K. mikimotoi was common but not at bloom levels (chlorophyll a~4.0 mg m-3). A mixed diatom-dinoflagellate community was the dominant the finalstage in the succession, as the summer thermocline was less well developed. Thephytoplankton biomass and composition in 2003 matches the classical model ofphytoplankton seasonal succession in temperate waters (Margalef, 1978; Smayda, 1980)but this was not obvious in 2004.In general, the FerryBox system on the Pride of Bilbao in 2003 and 2004 was successfuland improved understanding of the relationship between the phytoplankton populationand hydrographic regimes in 2003 and 2004 between Portsmouth and Bilbao.Improvements in future might include continuous observations of oxygen and nutrientsand more work can be done to link FerryBox data, satellite and CPR basedobservations

Techniques of efficient fertilizer management for wetland rice - a review.

Efficient fertilizer management was proved as a tool for increased crop production in an environmental friendly way. Nutrient response studies determine optimum economic doses for a particular nutrient under specific soil environment. Fertilizers need assessment entails, soil test results and nutrient response models. A few models for fertilizer rate calculation based on soil test values, are briefly discussed in this paper. The test results from site specific nutrient management (SSNM) model showed about 10% grain yield increase compared to that of farmers' practice in Asia. The results of several studies showed that the use of urea supper granule (USG), leaf color chart (LCC) and Soil Plant Analysis Division: Chlorophyll meter (SPAD) based on N fertilizer management increased N fertilizer use efficiency and reduces environmental risk. The mean yield values of 18 tidal prone sites of Bangladesh showed USG produced an average of 17.84% higher yield of MV rice and saved an average of 32.52% of N over prilled urea. N and K nutrients response in rice were best fitted to quadratic and square root quadratic, while for P response curve it was linear plateau. In clay loam soils of Bangladesh, a linear yield increase was observed from <3 to 6 mg kg-1 available P and then leveled-off up to 17 mg kg-1. Potassium fertilizer positive response was found up to 80 kg ha-1 of K in clay loam soils of Bangladesh. It can be concluded that for sustainable, efficient and environment-friendly rice production fertilizer application should be based on plant and soil tests, either it derived from different model or crop nutrient response study

First record of Caromiobenella helgolandica (Claus, 1863) (Copepoda, Monstrilloida) from the Saudi waters of the Arabian Gulf

Caromiobenella helgolandica (Claus, 1863), a presumedly widespread monstrilloid copepod, is reported for the first time from Saudi waters of the Arabian Gulf; only females were found in zooplankton samples collected from Tarut Bay in the Arabian Gulf. Caromiobenella Jeon, Lee, & Soh, 2018 is a recently described genus that is distinguished by having modified male antennules. The nauplii of monstrilloid copepods are endoparasitic on molluscs and polychaetes, while the adults are free-living reproductive forms. This study is an unprecedented record of C. helgolandica from the Arabian Gulf region

First record of Caromiobenella helgolandica (Claus, 1863) (Copepoda, Monstrilloida) from the Saudi waters of the Arabian Gulf

Caromiobenella helgolandica (Claus, 1863), a presumedly widespread monstrilloid copepod, is reported for the first time from Saudi waters of the Arabian Gulf; only females were found in zooplankton samples collected from Tarut Bay in the Arabian Gulf. Caromiobenella Jeon, Lee, & Soh, 2018 is a recently described genus that is distinguished by having modified male antennules. The nauplii of monstrilloid copepods are endoparasitic on molluscs and polychaetes, while the adults are free-living reproductive forms. This study is an unprecedented record of C. helgolandica from the Arabian Gulf region

Video_9_New depth records and novel feeding observations of three elasmobranchs species in the Eastern Red Sea.mp4

Understanding the vertical distribution of elasmobranch species and associated ecological dynamics can be a crucial component of developing effective conservation strategies, particularly in light of their global population decline. Previous studies have primarily focused on horizontal extent and movement patterns of elasmobranchs, with limited knowledge about their vertical distribution. This knowledge gap stems from limited access to technological advancements and reliance on surface data from fisheries operations. Today, advancements in observing platforms such as electronic tracking, remotely operated vehicles and submersibles, and reductions in costs for drop cameras and BRUVs, allow for direct observation of animals at great depths, facilitating improved understanding of their ecological and trophic niches. This study reports new global depth records for three elasmobranch species observed in the Saudi Arabian Red Sea (Carcharhinus altimus, Rhinobatos punctifer, Iago omanensis), also presenting ethological evidence on Iago omanensis feeding behavior. Our findings have significant implications for conservation strategies and the development of targeted conservation measures. The provisioning of data on new depth ranges allows places like NEOM to better manage and protect deep sea habitats, due to the presence of species occurring at those depths.</p