Accumulation of Trace Metals, Petroleum Hydrocarbons, and Polycyclic Aromatic Hydrocarbons in Marine Copepods from the Arabian Gulf

In this study, zooplankton samples were collected from the coastal waters of Qatar during winter and summer 1998 to assess the impact of growing industrialization on the bioaccumulation of trace metals, total petroleum hydrocarbons (TPHCs) and polycyclic aromatic hydrocarbons (PAHs) in copepods, the dominant zooplankton group and main food for fish in the Arabian Gulf

Prevalence of Chlamydia trachomatis among women attending gynecology and infertility clinics in Gaza, Palestine

SummaryBackgroundChlamydia trachomatis is an obligate intracellular bacterium characterized by a biphasic developmental cycle of replication. The organism is recognized as one of the major causes of sexually transmissible human bacterial infection throughout the world. Since there have been no previous studies dealing with chlamydial diagnosis in Palestine, this study was conducted to determine the prevalence of C. trachomatis infection among women attending gynecology and infertility clinics.MethodsEndocervical swabs were collected from 109 women, aged 18–52 years (median 29 years), attending gynecology and infertility clinics in Gaza. These specimens were processed using molecular (polymerase chain reaction, PCR) and enzyme immunoassay (EIA; IDEIA™ PCE Chlamydia) techniques.ResultsThe results obtained show that the overall prevalence rate of C. trachomatis was 20.2%. The sensitivity was 73% for the EIA, 86% for the MOMP (major outer membrane protein gene)-based PCR, and 100% for the plasmid-based PCR. Meanwhile the specificity was 94% for the EIA, 98% for the plasmid-based PCR, and 100% for the MOMP-based PCR. In multivariate analysis, only cervical discharge was significantly associated with positivity for C. trachomatis (adjusted odds ratio 5.6, 95% confidence interval 2.0–15.5; p=0.001).ConclusionsThe study revealed that a significant proportion of Palestinian women expressed evidence of exposure to C. trachomatis. Women with cervicitis are more likely to have been previously infected or exposed to Chlamydia infection. Furthermore, PCR proved to be superior and more efficient in the diagnosis of C. trachomatis than EIA

Environmental Drivers of Habitat Use by Hawksbill Turtles (Eretmochelys imbricata) in the Arabian Gulf (Qatar)

Understanding the environmental drivers of movement patterns are critical to the protection, management and recovery of endangered species. The Arabian Gulf is considered to be the hottest marine system in the world and is known for its extreme environmental conditions that pose substantial physiological stress on marine organisms living there. Satellite tags were deployed on hawksbill turtles in the Arabian Gulf and quantitative ecological modeling (i.e., Bayesian state-space models and GAMMs) was used to provide new insights into the ecological basis of observed hawksbill movement and behavior. Hawksbills used a relatively large core area in the southeast Arabian Gulf when transit and area-restricted search behaviors were included. The numerous hotspots identified suggest that important habitat occurs along a large area of the Qatari eastern coastline and into Saudi Arabia. Offshore islands with fringing reef habitat and deep-water habitats near the 30–50 m isobaths were intensely used. Hawksbills made seasonal migrations to deep-water habitat during summer months, typically once SST reached ∼33°C and bottom temperature reached ∼32°C. These data provide valuable information to managers seeking to conserve hawksbills in the region. Our data also provide a context to understand the underlying physiological, energetic and behavioral drivers of hawksbill movement in the Arabian Gulf. Future studies should include the use of biologging devices, benthic surveys, and dietary biomarkers to better understand the seasonal migrations of Arabian Gulf hawksbills to this deep-water region.This work was funded by the Qatar National Research Fund, National Priorities Research Program 5-642-1-110. The open access publishing fees for this article have been covered by the Texas A&M University Open Access to Knowledge Fund (OAKFund), supported by the University Libraries

Extreme 15N Depletion in Seagrasses

Seagrass beds form an important part of the coastal ecosystem in many parts of the world but are very sensitive to anthropogenic nutrient increases. In the last decades, stable isotopes have been used as tracers of anthropogenic nutrient sources and to distinguish these impacts from natural environmental change, as well as in the identification of food sources in isotopic food web reconstruction. Thus, it is important to establish the extent of natural variations on the stable isotope composition of seagrass, validating their ability to act as both tracers�of nutrients and food sources. Around the world, depending on the seagrass species and ecosystem, values of seagrass N normally vary from 0 to 8 ? ?15N. In this study, highly unusual seagrass N isotope values were observed on the east coast of Qatar, with significant spatial variation over a scale of a few metres, and with ?15N values ranging from +2.95 to ?12.39 ? within a single bay during March 2012. This pattern of variation was consistent over a period of a year although there was a seasonal effect on the seagrass ?15N values. Seagrass, water column and sediment nutrient profiles were not correlated with seagrass ?15N values and neither were longer-term indicators of nutrient limitation such as seagrass biomass and height. Sediment ?15N values were correlated with Halodule uninervis ?15N values and this, together with the small spatial scale of variation, suggest that localised sediment processes may be responsible for the extreme isotopic values. Consistent differences in sediment to plant 15N discrimination between seagrass species also suggest that species-specific nutrient uptake mechanisms contribute to the observed ?15N values. This study reports some of the most extreme, negative ?15N values ever noted for seagrass (as low as ?12.4 ?) and some of the most highly spatially variable (values varied over 15.4 ? in a relatively small area of only 655�ha). These results are widely relevant, as they demonstrate the need for adequate spatial and temporal sampling when working with N stable isotopes to identify food sources in food web studies or as tracers of anthropogenic nutrients.Scopu

Spatial distribution of heavy metals in the middle nile delta of Egypt

Heavy metal contamination in the El-Gharbia Governorate (District) of Egypt was identified by using remote sensing, Geographical Information Systems (GIS), and X-ray fluorescence (XRF) spectrometry as the main research tools. Digital Elevation Model (DEM), Landsat 8 and contour map images were used to map the landforms. Different physiographic units in the study area are represented by nine soil profiles. X-ray fluorescence spectrometry (XRF) was used for geochemical analysis of 33 soil samples. Vanadium (V), nickel (Ni), chromium (Cr), copper (Cu) and zinc (Zn) concentrations were measured and they all exceeded the average global concentrations identified by Wedepohl (1995). Ni and Cr concentrations exceeded recommended values in all soil profile horizons (Canadian Soil Quality Guidelines, 2007), while Cu had a variable distribution. Zn concentrations are under recommended concentration limits in most soil samples. Contamination Factor, Pollution Load Index and Degree of Contamination indices were used to assess the environmental risks of heavy metal contamination from the soils. All analysed metals pose some potential hazard and pollution levels were particularly high near industrial and urban areas.Open Access funded by International Research and Training Center on Erosion and Sedimentation and China Water and Power Pres

Trace element composition of size-fractionated suspended particulate matter samples from the Qatari Exclusive Economic Zone of the Arabian Gulf: the role of atmospheric dust

We analyzed net-tow samples of natural assemblages of plankton, and associated particulate matter, from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf. Size-fractionated suspended particles were collected using net tows with mesh sizes of 50 and 200 μm to examine the composition of small- and large-size plankton populations. Samples were collected in two different years (11 offshore sites in October 2012 and 6 nearshore sites in April 2014) to examine temporal and spatial variabilities.We calculated the excess metal concentrations by correcting the bulk composition for inputs from atmospheric dust using aluminum (Al) as a lithogenic tracer and the metal=Al ratios for average Qatari dust. Atmospheric dust in Qatar is depleted in Al and enriched in calcium (Ca), in the form of calcium carbonate (CaCO3), relative to the global average Upper Continental Crust (UCC). To evaluate the fate of this carbonate fraction when dust particles enter seawater, we leached a subset of dust samples using an acetic acid–hydroxylamine hydrochloride (HAc–HyHCl) procedure that should solubilize CaCO3 minerals and associated elements. As expected, we found that Ca was removed in Qatari dust; however, the concentrations (ppm) for most elements actually increased after leaching because the reduction in sample mass resulting from the removal of CaCO3 by the leach was more important than the loss of metals solubilized by the leach. BecauseQatar National Research Fund (QNRF) under the National Priorities Research Progra

Short-term behavioural responses to thermal stress by hawksbill turtles in the Arabian region

We present a previously unrecorded short-term behavioural response by hawksbill sea turtles to elevated sea surface temperatures in the Persian/Arabian Gulf. Surface waters typically exceed 30°C for sustained periods during the summer, and can be likened to a natural living laboratory for understanding thermoregulatory behaviour by marine species in the face of climate change and elevated global temperatures. We satellite-tracked 90 post-nesting hawksbill turtles between 2010 and 2013 as part of a larger programme to elucidate turtle foraging habitats and post-nesting behaviour. We used 66 of these datasets, where turtles clearly departed and returned to foraging grounds, for these analyses. Sea surface temperatures during the summer averaged 33.5°C and peaked at 34.9°C. During these elongated periods of elevated temperatures (June–August) the turtles temporarily migrated an average of 70km to deeper and cooler waters at northern latitudes, returning after 2–3months (September–October) back to original feeding grounds. Temperature differential T∆ between foraging and summer loop habitats was significantly different and approximated −2°C. Turtles undertaking summer migration loops generally moved in a north-easterly direction toward deeper water, returning in a south-westerly direction to the shallower foraging grounds. Swim speeds were significantly higher and orientation was less omnidirectional during the migrations than when foraging. The outbound migrations were significantly inversely correlated with temperature, but were not linked to chlorophyll-a, geostrophic currents or sea surface height. The turtles' preference for returning to the same foraging grounds suggests a lack of other substantial influences which might have precipitated the temporary summer migration loops. Our results indicate that Gulf hawksbills employ thermoregulatory responses which take them out of high temperature and potentially physiology-threatening conditions. These findings improve our overall understanding of hawksbill habitat use and behaviour in a climate-challenged environment, and support sea turtle conservation-related policy decision-making at national and regional levels.Emirates Wildlife Society—World Wild Fund for Nature Office. 7Days, Abu Dhabi Urban Planning Council, Bridgestone, CASP, College of the North Atlantic, Qatar, Deutsche Bank, Dubai Electricity & Water Authority, Dubai Festival City, Emirates Palace, Environment & Protected Areas Authority, Sharjah, Environment Agency—Abu Dhabi, Fairmont, Géant, Gulftainer, HSBC, Intercontinental, Dubai Festival City, Jebel Ali Golf Resort & Spa, Jumeirah Etihad Towers, Linklaters, Momentum Logistics, Mubadala, Murjan Marinas, Nokia, Sheikha Salama bint Hamdan Al Nahyan Foundation, The Club, TimeOut Dubai, and the Young Presidents Organisation

Identification of Important Sea Turtle Areas (ITAs) for hawksbill turtles in the Arabian Region

We present the first data on hawksbill turtle post-nesting migrations and behaviour in the Arabian region. Tracks from 90 post-nesting turtles (65 in the Gulf and 25 from Oman) revealed that hawksbills in the Arabian region may nest up to 6 times in a season with an average of 3 nests per turtle. Turtles from Qatar, Iran and the UAE generally migrated south and southwest to waters shared by the UAE and Qatar. A smaller number of turtles migrated northward towards Bahrain, Saudi Arabia and one reached Kuwait. Omani turtles migrated south towards Masirah island and to Quwayrah, staying close to the mainland and over the continental shelf. The widespread dispersal of hawksbill foraging grounds across the SW Gulf may limit habitat protection options available to managers, and we suggest these be linked to preservation of shallow water habitats and fishery management. In contrast, the two main foraging areas in Oman were small and could be candidates for protected area consideration. Critical migration bottlenecks were identified at the easternmost point of the Arabian Peninsula as turtles from Daymaniyat Islands migrate southward, and between Qatar and Bahrain. Overall, Gulf turtles spent 68% of the time in foraging ground with home ranges of 40–60km2 and small core areas of 6km2. Adult female turtles from Oman were significantly larger than Gulf turtles by ~11cm x¯=81.4CCL and spent 83% of their time foraging in smaller home ranges with even smaller core areas (~3km2), likely due to better habitat quality and food availability. Gulf turtles were among the smallest in the world x¯=70.3CCL and spent an average of 20% of time undertaking summer migration loops, a thermoregulatory response to avoid elevated sea surface temperatures, as the Gulf regularly experiences sustained sea surface temperatures >30°C. Fishery bycatch was determined for two of the 90 turtles. These spatio-temporal findings on habitat use will enable risk assessments for turtles in the face of multiple threats including oil and gas industries, urban and industrial development, fishery pressure, and shipping. They also improve our overall understanding of hawksbill habitat use and behaviour in the Arabian region, and will support sea turtle conservation-related policy decision-making at national and regional levels.Emirates Wildlife Society–World Wild Fund for Nature. 7Days, Abu Dhabi Urban Planning Council, Bridgestone, CASP, College of the North Atlantic-Qatar, Deutsche Bank, Dubai Electricity & Water Authority, Dubai Festival City, Emirates Palace, Environment & Protected Areas Authority, Sharjah, Environment Agency–Abu Dhabi, Fairmont, Géant, Gulftainer, HSBC, Intercontinental, Dubai Festival City, Jebel Ali Golf Resort & Spa, Jumeirah Etihad Towers, Linklaters, Momentum Logistics, Mubadala, Murjan Marinas, Nokia, Sheikha Salama bint Hamdan Al Nahyan Foundation, The Club, TimeOut Dubai, and the Young Presidents Organisation

Geochemical composition of dust from Qatar peninsula

Atmospheric dust samples have been collected from different areas in Qatar and analyzed for major and trace element composition. This region of the Arabian Gulf represents an area largely affected by dust from natural and anthropogenic sources. Twenty one samples were collected during 2014 and 2015 from Al-Khor, Katara, Sealine, Al-Waab, and Qatar University by passive and active sampling techniques. Some bulk samples were collected during the massive megastorm that occurred in April 2015. Back trajectories were determined for each sample set using the NOAA HYSPLIT model over a 50 hour time interval. Samples were equally divided between northerly (n=12; northern Saudi Arabia, Kuwait or Iraq) and southerly (n=8; SE Saudi Arabia, United Arab Emirates and Oman) sources. One sample is expected to originate from westward, in Saudi Arabia. There is more variability noticed in source locations throughout the winter months (October to March), with more of them coming from the south (9 times) compared to summer months (April to September) for twice only. Dust samples were microwave-assisted, total acid digested (HF+HCl+HNO3) and oxidized with H2O2 before analyses were conducted by ICP-OES. Only 12 out of 23 elements (Al, Ca, Fe, K, Mg, Na, Ag, As, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sr, V, Zn, P) of the Qatari dust samples were enriched relative to Upper Continental Crust (UCC). Calcium was especially enriched to a level of 400% relative to UCC. About 33% of the total sample mass was CaCO3, reflecting the composition of surface rocks in the source areas. Of the elements typically associated with anthropogenic activity, Ag, Ni, and Zn were the most enriched relative to UCC, with enrichment factors of 182%, 233%, and 209%, respectively. Other metals like Pb and V were not significantly enriched, with enrichment factors not exceeding 25% and 3%, respectively. Major elements (Al, Mn and Fe) were depleted relative to UCC due to the strong enrichment of CaCO3, with enrichment factors of -58%, -35% and -5%, respectively. Samples with northern and southern origins were separated to investigate if the elemental composition could be used to identify source/origin. Only three elements were observed to have a statistical difference. Pb and Na were higher in the samples collected from the south while Cr was higher in those from the north. This study aims to investigate present-day geochemistry of dust particles and its effect on the marine environment of the Arabian Gulf. The geochemical composition of dust is essential component for correcting lithogenic input to water column suspended matter samples.qscienc

Present Limits to Heat-Adaptability in Corals and Population-Level Responses to Climate Extremes

Climate change scenarios suggest an increase in tropical ocean temperature by 1–3°C by 2099, potentially killing many coral reefs. But Arabian/Persian Gulf corals already exist in this future thermal environment predicted for most tropical reefs and survived severe bleaching in 2010, one of the hottest years on record. Exposure to 33–35°C was on average twice as long as in non-bleaching years. Gulf corals bleached after exposure to temperatures above 34°C for a total of 8 weeks of which 3 weeks were above 35°C. This is more heat than any other corals can survive, providing an insight into the present limits of holobiont adaptation. We show that average temperatures as well as heat-waves in the Gulf have been increasing, that coral population levels will fluctuate strongly, and reef-building capability will be compromised. This, in combination with ocean acidification and significant local threats posed by rampant coastal development puts even these most heat-adapted corals at risk. WWF considers the Gulf ecoregion as “critically endangered”. We argue here that Gulf corals should be considered for assisted migration to the tropical Indo-Pacific. This would have the double benefit of avoiding local extinction of the world's most heat-adapted holobionts while at the same time introducing their genetic information to populations naïve to such extremes, potentially assisting their survival. Thus, the heat-adaptation acquired by Gulf corals over 6 k, could benefit tropical Indo-Pacific corals who have <100 y until they will experience a similarly harsh climate. Population models suggest that the heat-adapted corals could become dominant on tropical reefs within ∼20 years